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ANNUAL REPORT

OF

PROGRAM ACTIVITIES

U : NATIONAL HEART AND LUNG INSTITUTE

Fiscal Year 1973

Part II

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE Public Health Service National Institutes of Health

INTRAMURAL RESEARCH

NATIONAL HEART AND LUNG INSTITUTE

July 1, 1972 - June 30, 1973

INTRAMURAL RESEARCH

Project Reports Cardiology Branch

Summary 1

1. Phosphorylation of human platelet myosin and contractile

proteins from other sources 11

2(c) Characterization of cardiac contractile proteins from

patients with idiopathic hypertrophic subaortic stenosis 12

3(c) Echocardiographic findings in patients with idiopathic

hypereosinophilic syndromes 13

4. Effect of lidocaine and of elevating arterial pressure on the incidence of spontaneous ventricular fibrillation in

dogs during coronary occlusion 14

5. Effect of nitroglycerin on the incidence of spontaneous ventricular fibrillation during coronary occlusion in dogs- 16

6(c) Echocardiographic assessment of secondary cardiomyopathies- 17 7(c) ASH masquerading as coronary artery disease and idiopathic

myocardial hypertrophy 18

8(c) Electrocardiographic findings in 100 patients with

asjonmetric septal hypertrophy 19

9(c) Familial incidence and genetic transmission of IHSS 20

10(c) Coronary collateral function in patients without coronary

artery disease 21

11. Visualization of acute myocardial infarction by the Radionuclide Gallium-67 22

12. Lack of deleterious effects of vagally mediated brady- cardia during acute myocardial ischemia in the dog 23

13(c) Effects of nitroglycerin on coronary collateral function

in patients with coronary occlusive disease 24

14. Failure of nitroglycerin to alleviate acute myocardial

ischemia or improve collateral flow when M^02 is held con- stant in the heart-lung preparation 26

15(c) Quantification of ventricular regularization in atrial

f ibrillation 27

16(c) Quantitative assessment of left ventricular function in

man utilizing roentgen videodensitometry 29

17. Adrenergic influences on ventricular fibrillation threshold

and post-occlusion arrhythmias 30

18(c) Factors affecting the operative mortality in aortic

valATular disease 3 2

19(c) Mitral valve position in patients with asymmetric septal

hypertrophy 33

20. A video scanner-analog computer system for the analysis of

routine echocardiograms 35

21(c) Long-term effects of operation on obstruction and LV

hypertrophy in IHSS 36

22(c) Distribution of the cardiomyopathy in IHSS 37

23(c) Non- invasive determination of the pressure gradient in

patients with idiopathic hypertrophic subaortic stenosis 39

24(c) Echocardiographic diagnosis of IHSS by detection of

asymmetric septal hypertrophy 41

25(c) The clinical characteristics of obstructive and non- obstructive asymmetric septal hypertrophy 42

26(c) A real time system for two-dimensional echocardiography 43

27(c) Effects of operation on the cardiac response to exercise

in patients with IHSS 45

28. Reduction in extent of myocardial infarction when nitro- glycerin and methoxamine are administered during coronary occlusion 46

29(c) Preoperative predictors of the long-term results of wave

replacement in patients with aortic regurgitation 47

30(c) Characterization of the cardiac response to exercise and effects of propranolol in patients with asymmetric septal hy pe r t r ophy 4 9

31. Cholinergic innervation of the cardiac conduction system: autonomic and functional correlations 51

32. Electrical stability of acutely ischemic myocardium: Inde- pendent influences of heart rate and vagal tone 53

33. The electrical stability of acutely ischemic myocardial effects of nitroglycerin 55

34. The role of prostaglandins in the control of coronary vascular tone 56

35. Physiological and biochemical characteristics of a new

group of inotropic agents: Analogues of angiotensin II 58

36(c) Differences in distribution of morphologic abnormalities

in patients with obstructive and non-obstructive asymmetric

septal hypertrophy (ASH) : Light and electron microscopic

ob s e rva t io ns 5 9

37(c) Significance of multiple intercalated discs in hyper-

trophied human myocardium 61

38(c) Postoperative response to intense upright exercise in patients with ventricular septal defect and pulmonary hypertension: relation of impairment to age at operation 62

39(c) The occurrence of a-glycogen in human cardiac muscle cells- 63

40(c) Unusual evolution of acquired infundibular pulmonary stenosis in patients with ventricular sepal defect: Clinical and morphologic observations 64

41(c) Ultrastructural features of myocardial cell degeneration in

patients with cardiac hypertrophy 65

42. Effects of vagal stimulation on survival during experi- mental acute myocardial infarction 66

43(c) Evaluation of the ability of echocardiography to measure

alterations in left ventricular volume 67

44(c) Use of biventricular cineangiography in the evaluation of

patients with asymmetric septal hypertrophy 68

45(c) Echocardiography during upright exercise 69

46(c) Sustained effects of nitroglycerin ointment in patients

with angina pectoris 70

47(c) Deterioration of myocardial function following aorto-

coronary bypass operation 71

48. Increased myocardial ischemia caused by reflexly induced

hypotension during coronary occlusion in the conscious dog- 72

ii

Clinic of Surgery

Summary 73

49(c) NU-5 atomic powered pacemaker experimental and clinical

evaluation 79

50(c) Long-term follow-up of patients with congenital aortic

stenosis treated with aortic commissurotomy 80

51. The pathophysiology of intimal hyperlasia of the venous

graft in the arterial system 81

52(c) Silastic ball variance detection 82

53(c) Light and electron microscopic evaluation of hypertrophied right ventricular outflow tract muscle from patients with

; I congenital heart disease 83

'"-']'.', 54(c) Assessment of aortic regurgitation in patients with the

use of the Doppler Bidirectional Velocitometer 84

55, Experimental production of progressive mitral stenosis 85

, . , 56. The effects of naloxone hydrochloride on ventricular

irritability 86

57(c) Clinical effects of abrupt decrease in left atrial pressure

on renal sodium excretory patterns 87

58. Systemic and renal responses to a graded reduction in

cardiac output ' 88

59. Blood volume expansion without altering hematocrit. Renal effects in a cross-transfusion model 89

60. Systemic and renal effects of methyl prednisolone following

a graded reduction in cardiac output 90

61. Apical-aortic valvular anastomosis for diffuse left ventricular outflow tract obstruction 91

62. Experimental evaluation of the membrane oxygenator 92

63. Transcutaneous measurement of aortic regurgitation with

a Doppler Velocitometer 93

64. A new canine model for echocardiographic evaluation of myocardial function 94

65. A comparison of left ventricular pressure, aortic flow and echocardiography in determining the response of left ventricular function or propranolol 95

66. Experimental creation of infundibular pulmonic stenosis ventricular septal defect and right ventricular hyper- tension in puppies 96

" 67(c) A review of eighteen years experience with total correction

of tetralogy of Fallot at the NIH 97

68. The experimental creation of infundibular pulmonic stenosis

and demonstration of its hemodynamic relationships 99

69. Hemodynamic and anatomic evaluation of experimental

valvular aortic stenosis 101

70. Effects of aortic stenosis on (A) coronary blood flow and

(B) regional distribution of blood flow 102

71. Hypothermic asanguineous circulatory arrest (HACA) 103

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Summa ry -^ 105

72. A new radiochemical esterolytic assay for human urinary urokinase 117

73. Clinical biochemistry of the kallikrein-kinin system 119

74. Peptide biochemistry 122

75. Studies on the enzymes involved in the activation of human plasma kallikrein: PF/dil and Hageman Factor 124

76(c) Antigen-antibody-induced release of mediators from

passively sensitized human lung: Studies on histamine and arginine esterases 128

77. Biochemistry of the kallikrein-kininogen-kinin system 130

78. The role of prostaglandins in the vascular system 133

79. Studies on the isolation and characterization of clostridial electron transfer proteins and other iron- sulfur proteins 135

80(c) Effect of renal infarction on aromatic amino acid decar- boxylase levels in serum and kidney tissue 138

81. Characterization of bovine adrenal dopamine 3-hydroxylase- 140

82. The regulation of the hydroxyindole pathway of tryptophan

me tabolism 142

83. In vivo protein synthesis in heart, aorta, and mesenteric artery of normotensive and spontaneously hypertensive rats

84. Studies on 5,6- and 5, 7-dihydroxytryptamine Agents that

cause degeneration of serotonergic neurons 147

85. Studies on serotonin N-acetyl-transf erase in mammalian

pineal glands 149

86. Studies on tryptophan hydroxylase 153

87. Monoamine metabolism and blood pressure of spontaneously hypertensive rats 155

88. Strain differences of catecholamine synthesizing enzyme activity in the rat 158

89. cAMP dependent protein kinase in vascular smooth muscle

and its relationship to calcium uptake 160

90(c) The effects of varying salt intake and of acute saline

infusion on norepinephrine and dopamine excretion in man 162

91(c) Clinical investigation of cardiovascular drugs 164

92. The role of endogenous prostaglandin synthesis in the

control of the coronary circulation 167

93(c) The role of renal prostaglandins in sodium homeostasis

and blood pressure regulation in man 170

94(c) Studies on the biological role of histamine: Alteration of

histamine metabolism in man and animals by salicylates and

other inhibitors 172

95(c) The biological role of histamine and monoamines: Studies

of histaminase and other enzyme activities in medullary

thyroid carcinoma and hyperlipoproteinemia 175

96. The biological role of histamine and other amines: Participation of histamine and serotonin in inflammation 179

97. Studies on the biological role of histamine and poly- amines: Ornithine decarboxylase and histaminase activities

in rat thymus and other organs 182

98(c) Metabolism of hydroxyproline and collagen 185

99(c) Studies on the interrelationships between the renin- angiotensin system, urinary and plasma kallikrein and prostaglandins in normal volunteers and hypertensive

patients 188

100. Effects of tolbutamide on plasma renin activity (P.R.A.) 190 101(c) Urinary and plasma kallikrein 192

102. Studies on renal catecholamine synthesis 195

103. Acute effects of alphamethyldopa on plasma renin activity- 197 104(c) Effects of steroid, thyroid and protein hormones, electro- lytes and psychodelic agents on neural and sensory

f unc tion 199

105(c) Trace metal metabolism 206

106(c) Taste and olfaction 217

Molecular Hematology Branch

Summary 23 7

107. Metabolism of globin mRNA transcription in bone marrow

cells 239

108. The mechanism of hemoglobin biosynthesis in rabbit reticulocyte cell-free systems 240

109(c) Regulation of hemoglobin chain synthesis in beta-

thalassemia 242

110. Evolutionary homology of components of the protein synthesizing machinery 244

111. The mechanism of hemoglobin switching in sheep and goats 246

112. Mechanism of action of the enzjnne RNA-directed DNA

p o lyme r as e 248

Laboratory of Technical Development

Summary 251

113. Discrete cell temperature measurement study 259

114. Development of stopped-flow micro-calorimetry for the study of biochemical and cellular reactions; applications

to clinical biochemistry 262

115. The development of methods for investigating the mechanism of biochemical reactions important in cardiology, pul- monary and respiratory function, and in the circulation 265

116. An automated method for rapid bacterial and mammalian cell growth and assay 269

117. Fluorescent complexes of proteins 273

118. Methodology in fluorescence measurements 276

119. Applications of fluorescence in biochemistry 279

120. Countercurrent chromatography: Liquid-liquid partition chromatography without solid support (Part II) 282

121. Countercurrent chromatography: Liquid-liquid partition chromatography without solid support (Part I) 286

122(c) Development of the spiral coil membrane blood oxygenator and systems for long-term temporary support of pulmonary and cardiovascular systems 290

123. Blood flow measurement using nuclear magnetic resonance

te chniques 295

124. Peltier-seebeck equilibrator 298

125. Pseudo differentiator 300

126. Measurement of picomole amounts of carbon dioxide 301

127. Calorimetric measurement of carbon dioxide 303

Laboratory of Kidney and Electrolyte Metabolism

Summary 307

128. The effect of chlorpropamide on the water permeability response of the toad bladder to vasopressin 313

129. A study of the leakage of cyclic AMP from the toad

urinary bladder 315

130. A study of the concentration of cyclic AMP in the urinary bladder of the toad 317

131. Function of the early distal tubule of frog 320

132. Function of the thick ascending limb of Henle's loop 322

133. The study of ion transport in renal cortical collecting tubules 3 25

134. Mechanism of salt and water transport by proximal renal

t ubu 1 e s 328

135. Volume regulation in duck erythrocytes. Hormonal control

of cation transport in duck erythrocytes 330

136. Effect of cardiac glycosides on the excitation-contraction system in mammalian skeletal muscle 334

Pulmonary Branch

Summary - Section on Pulmonary Biochemistry 339

137(c) Sites of action and physiologic importance to some

mediators of the type I allergic reaction in man 341

138. Models of lung growth 343

139. Mechanism of collagen and non-collagen protein synthesis

in rabbit lung cell-free systems 345

140(c) The composition and synthesis of collagen in human lung 347

Laboratory of Chemistry

Summary 3 49

141. A study of organic and bio-organic systems by magnetic resonance 355

142. Mass spectrometry and structure of natural products 358

143. Structural characterization of natural products 361

144. X-ray crystallographic studies of molecules of interest for theoretical reasons and for understanding of modes

of physiological actions 364

145. Theoretical and computational investigations of the limitations of small-angle X-ray scattering 367

146. The characterization of natural materials 368

Laboratory of Biochemistiry

Summary 371

147. Studies on the anaerobic metabolism of the branched-

148. Biochemical genetics of NH^-assimilatory enzymes in

149. Kinetics and mechanisms of biochemical reactions 392

150. 1. Anaerobic metabolism of certain amino acids and other

nitrogen compounds with especial reference to the role of B]^2 coenzyme and to electron transfer and phosphory- lation reactions involved. 2. Methane biosynthesis and one-carbon compound

metabolism 398

vi

151. 1. Studies on pyridoxal-P and B-.^ coenz3rrae-dependent

amino mutases. 2. Studies on 3,5-diaralnohexanoate dehydrogenase 402

152. Menadlone-dependent p-nltrophenylphosphatase of

Clostridium stlcklandll 405

153. Ciliary structure and function.

1. Motility: Energy transducing proteins.

2. Mlcrotuble structure: a. Mutants resistant to drugs which Inhibit normal microtubule assembly, b. Tubulin affinity labeling with podophyllotoxln derivatives 407

154. Enzyme structure and mechanisms of action and control 411

155. Regulatory proteins of glutamlne synthetase from E^. coll separation, purification, and regulatory mechanisms 418

156. 1. Components Involved In the adenylylation and

deadenylylatlon of glutamlne synthetase from Pseudomonas putlda 2. Preparation and characterization of E-adenylylated

glutamlne synthetase 470

157. 1. Kinetic reaction mechanism of the y-glutamyl trans-

ferase activity of E^. coll glutamlne synthetase. 2. Purification and properties of the Pjj regulatory protein associated with the E^. coll ATP: Glutamlne synthetase adenylyl transferase 422

158. Regulation of nitrogen metabolism In E^ coll W. The application of continuous culture techniques 425

159. 1. Stereochemical studies of enzymatic reactions

2. Synthetic studies of organic compounds of biological

Interest 429

160. DNA synthesis In E^ coll 433

f'161. Studies on the binding site of mouse myeloma protein,

specific for the 2,4-dlnltrophenyl (DNP) group 436

162. Adenosine triphosphate - actln Interactions. Application of a contact-labeling technique to elucidation of the

protein binding site 438

163. Studies on the self-radlolysls of chymotrypsln, labeled with a trltlated dllsopropylphosphoryl (DIP) group. Re- lationship of free-radical distribution to binding site composition 440

164. Proteolytic fragmentation of fibrinogen 442

165. Structure of enzymatic fragments of fibrinogen 444

166. The Interaction of actln and myosin 446

167. Control of the Interaction of actln and myosin by native tropomyosin ' 449

168. Resolution and characterization of the electron transport chain of E. coll 451

169. The enzymatic propertels of SH]^ blocked myosin and its interaction with actln and ATP 454

170. Membrane biochemistry: Chemical composition and molecular organization of the amoeba plasma membrane 457

vii

171. Membrane biochemistry: Mechanism of membrane fusion in

amoeba in relation to endocytosis 460

172. Cytology of Acanthamoeba 463

Laboratory of Chemical Pharmacology

Summary 465

173. Acetaminophen-induced liver necrosis. I. Relationship between hepatic necrosis and the covalent binding of an acetaminophen metabolite to liver macromolecules 473

174. Acetaminophen-induced liver necrosis. II. Protective role

of glutathione 474

175. Acetaminophen-induced liver necrosis. III. Relationship between severity of liver necrosis and urinary metabolites

of acetaminophen 479

176(c) Acetaicinophen-induced liver necrosis. IV. Clinical

177. Acetaminophen-induced necrosis. V. N-oxidation of acetanilide analogues 485

178. The role of cytochrone P-450 in N-hydroxylation of N- acetylarylamines. Studies with 2-acetylaminofluorene

179. Role of drug-metabolism in the hemolysis caused by aniline

in rats 489

180. Role of the methemoglobinemia in hemolysis caused by

aniline and acetanilide in rats 493

181. Furosemide-induced hepatic and renal tubular necrosis. I. Occurrence of tissue lesions and modulation of the toxicity by treatments which alter drug-metabolizing

act ivi ty 496

182. Furosemide-induced hepatic necrosis. II, Comparison of necrosis with covalent binding of furosemide 498

183. Drug-induced necrosis in the kidney: Comparison of

mercuric chloride, p-aminophenol and furosemide 500

184. Possible role of cytochrome c^ reductase and cytochrome P-450 in the covalent binding of halome thanes to micro- somal protein - studies using specific antibody against cytochrome c^ reductase and by specific destruction of cytochrome P-450 502

185. Mechanism of renal toxicity-induced by chloroform 507

186. Relationship between covalent binding of aromatic hydro- carbons to lungs and production of bronchial necrosis 510

187. Biochemical changes after acetaminophen and furosemide- induced liver injury 516

188(c) Isoniazid-related hepatitis in man: Significance of ab- normal liver function tests during prophylactic therapy and correlation of susceptibility with acetylator pheno- ty pe 5 18

189. Isoniazid-induced hepatic damage: Investigations of the possible formation of an alkylating metabolite 521

190. The influence of pretreatment of rats on isoniazid metabolism 524

191. Spironolactone and testicular cytochrome P-450: Decrease of cytochrome P-450 and progesterone 17a-hydroxylase after spironolactone administration 527

viii

192. Toxic effects of l,l'-dlinethyl-4,4'-dipyrldilium di-

chloride (paraquat) in the rat and rabbit 530

193. Mechanism of dimethylnitrosamine-lnduced liver toxicity 533

194. Covalent binding as a basis of toxicity of chloramphenicol: Possible modification of structure to diminish toxicity of chloramphenicol without loss of antibacterial activity 535

195. Drug metabolism in fetal tissue 537

196. Interaction between nitrofurazone and various tissues

197. Effect of chronic treatment with phenobarbital or 3- methylcholanthrene on cytochrome P-450 and metabolic

activity in testes, adrenals, lungs and liver 541

198. Studies on the role of NADH in the metabolism of drugs

by cytochrome P-450 enzymes in liver microsomes 547

199. Development of a histochemical method for the assay of glutathione in tissues 550

200. The role of electrolytes in binding, mobilization and re- lease of norepinephrine in adrenergic neurons 552

201. Does sodium inhibit calcium-dependent mobilization of neurotransmitter at an intracellular or extracellular

site of action 555

202. The effects of exogenous metabolites of glycolysis on the retention of norepinephrine by rat heart slices 557

203. Studies on the potentiation of CCl/-induced hepatotoxicity in rats by pretreatment with ethyl alcohol, isopropanol,

or acetone 559

204. Mechanisms involved in thyprotective action of Dibenamine pretreatment against the hepatotoxicity of CCl, 562

205. Diene conjugation and lipid peroxidation as a mechanism

of hepatotoxicity 564

206. Temperature-dependent toxicity of adrenergic agonists in

mice 566

207. Studies on the in vivo covalent binding of CCl, and CCl^Br- 568

208. Studies on covalent binding as related to hepatotoxicity: comparison of CCL, and CBrCln 574

209. Covalent binding as a biochemical mechanism for toxicities: Covalent binding of stllbene to liver microsomes 579

210. The mechanisms of hydrazine toxicity 581

211. The role and mechanism of action of hormones in the control of cellular processes: I. The study of the effects of carbamylcholine on cyclic 3' ,5'-guanosine monophosphate

levels in the lung 584

212. The role and mechanism of action of hormones in the control of cellular processes. II. The role of GTP in the prostaglandin E-, activiation of the human blood platelet adenyl cyclase 587

213. Purification and characterization of the enzymatic ion transport system 589

214. Comparative pharmacology of receptor systems in smooth

ix

215. Studies on the chemical nature of the pharmacological receptor systems in vascular smooth muscle. I. Labeling studies of proteins associated with the a-adrenergic

receptor in rabbit aorta 595

216. Biochemical studies of the interaction of oxidant pollutants with the lung. I. The effect of N0„ on phospho- lipid bilayers 597

217. Physicochemical studies of lung surfactant lipoprotein 599

218. Physicochemical studies of complexes between drugs and biomolecules. XI. Fluorescence polarization as a tech- nique for measuring drug binding to plasma albumin 602

219. Physicochemical studies of complexes between drugs and biomolecules. XHI. Spin label studies of horse erythro- cyte carbonic anhydrases C and D 604

220. Physicochemical studies of complexes between drugs and biomolecules. XIV. A spin label study of avidin 606

221. Physicochemical studies of complexes between drugs and biomolecules. XV. A spin label study of azoester (methyl phenyldiazene carboxylate) induced damage to

human erythrocyte ghost membranes 608

Office of the Director, Intramural Research

222. Mathematical theory of renal function 611

223. Computer simulation of renal function 614

ODIR - Section of Pathology

Summary 61 7

224(c) Alcoholism an important but unemphasized factor predis- posing to infective endocarditis with reemphasis on the syndrome of pneumococcal endocarditis, meningitis and pneumonitis in alcoholics 625

225(c) The quadricuspid semilunar valve 626

226(c) A new cause of a diastolic murmur after replacement of

the aortic valve with a caged ball prosthesis 627

227(c) Calcification of prosthetic valve anuli: A late compli- cation of cardiac valve replacement 628

228(c) Mitral valvular disease. A clinicopathologic survey

of the conditions causing the mitral valve to function

ab no rma 1 ly 629

229(c) Pathologic anatony of the cardiomyopathies (idiopathic dilated and hypertrophic types, infiltrative types and endomyocardial disease with and without eosinophilia) 630

230 Lesions observed in arterial autogenous vein grafts

light and electron microscopic evaluation 631

231(c) Cardiovascular pathology in hyperlipoproteinemia

anatomic observations in 41 necropsy patients with

normal or abnormal serum lipoprotein patterns 632

232(c) Structural features of cardiac myxomas 633

233(c) Operative treatment of hypertrophic obstructive cardio- myopathy. The case against mitral valve replacement 634

234(c) The pathologic anatomy of cardiac valve replacement 635

235(c) Structural alterations in tissue cardiac valves

implanted in hiamans and calves 636

236(c) Non-rheumatic valvular cardiac disease. A clinico- pathologic survey of 27 different conditions causing valvular dysfunction 637

237(c) Ankylosing spondylitis and aortic regurgitation

description of the characteristic cardiovascular lesion

from study of 8 necropsy patients 638

238(c) Cardiac ultrastructural changes induced by daunorubicin

therapy 639

239(c) Early human arteriosclerosis 641

240(c) The coronary arteries and myocardium in acute myocardial

infarction and shock 643

241(c) Pathology of Sipple's syndrome 645

242(c) Chylomicrons and the formation of foam cells in type I

hyperlipoproteinemia 647

243(c) Ultrastructural studies of Tangier disease 648

244(c) Ultrastructure and cytochemistry of glycogen in cardiac

d is eas es 649

245(c) Intermyo fibrillar and nuclear-myo fibrillar connections in human and canine myocardium. An ultrastructural study 650

246(c) Plasma membrane extensions in intercalated discs of human myocardium and their relationship to partial dissociation of the discs 651

247(c) Fatal tachyarrhythmias associated with myofibrillar loss, mitochondrial hyperplasia and fatty change in myocardium. A new clinico-pathologic syndrome in children 652

ODIR - Section on Experimental Atherosclerosis

Summary 653

248. Blood velocity profiles and hemodynamic stresses in the aorta and its major branches, including the large coronary arteries 657

249. Vascular mechanics: arterial wall properties 658

250. The topography of experimental atherosclerotic lesions

in the dog and pig 661

251. Development of canine and miniature swine experimental atherosclerotic animal colonies 663

252. Endothelial nuclear orientation and morphology and its relation to hemodynamic factors- 665

253. An arterial life support system for study of plasma

protein transvascular transport mechanics 667

254. Re-endothelialization of eroded vascular interface 669

255. Growth and metabolism of the aortic smooth muscle cell and its response to various factors implicated in the pathogenesis of atherosclerosis 671

256. The rate and mechanisms of regression of various crystalline lipids placed in the arterial wall 672

257. Quantitation of 4 separate isotopes following oxygen combustion of plasma lipoproteins or aorta 674

258. Aortic metabolism of plasma lipoproteins 675

xl

259 Characterization of canine plasma lipoproteins in the

normal and hyperlipemic animal 677

260 Triglyceride lipase associated with the aortic endo-

thel ium 679

Molecular Disease Branch

S ummary 681

261(c) NHLI Type II coronary intervention study 693

262(c) The study of the lipid storage disease metachromatic

leulcodys trophy 696

263(c) Enzymatic studies in tissue lipid storage diseases 700

26A(c) Glycolipids and other lipid constituents of normal

human liver 705

265(c) Tissue lipidoses: Abnormal biochemistry in tissue lipid

storage diseases 708

266(c) The biochemistry and metabolism of plasma lipoproteins:

The metabolism of plasma lipoproteins in the rat 711

267 The biochemistry of plasma lipoproteins: The structure

of plasma lipoproteins in the rat 713

268(c) The biochemistry of plasma lipoproteins: The structure

of very low density lipoproteins 715

269(c) The biochemistry and metabolism of plasma lipoproteins:

Post-heparin lipolytic enzymes and their role in normal

and abnormal lipid transport and clearance 718

270 Structure-function relationships of the plasma apolipo-

pr o t eins 722

271 1. Chemistry and physical properties of human parathyroid

hormone (HPTH) . 2. Mass spectroscopic identification of the methyl and phenyl thiazolinone and thiohydantoin amino acids ob- tained from the automated edman degradation of poly- peptides and proteins. 3. Chemistry of the high density lipoprotein, apo-Lp-G-I

(A-I ) 7 24

272(c) The biochemistry and metabolism of plasma lipoproteins: The turnover and function of very low density, low

density and high density lipoproteins 731

273(c) Tissue lipidoses: Microscopic studies in tissue lipid

storage diseases 735

274(c) The biochemistry and metabolism of plasma lipoproteins:

Studies of familial hyperlipoproteinemia 738

275 The biochemistry and metabolism of plasma lipoproteins: A

study of a differentiated mouse liver cell line 747

276 The effect of insulin and dexamethasone on the metabolism

of mammalian cells in culture 751

277 Release of histamine from mast cells 754

278 Adipose tissue metabolism: Lipoprotein lipase 756

279 Role of cyclic AMP and cyclic CMP in modulation of growth, differentiation and aging of cells in culture 758

280 Effects of hormones on metabolism of adipose tissue

studied in vitro 760

xll

281 Investigation of the control of cyclic A^G' phospho- diesterase (PDL) activity in fat cells 762

282 Metabolism of Guanosine 3 *, 5 '-monophosphate in lung 76A

283 Adipose tissue hormone-sensitive lipase: Mechanisms for regulation of activity 767

Laboratory of Biochemical Genetics

284 Gene expression in neuroblastoma x glioma hybrid cells 777

285 Biochemical assays for action potential or receptor ionophores 778

286 Selection for cells of neuronal origin synthesizing

specific transmitters 779

287 Development of cell lines with neuronal phenotypes 780

288 Study of acetylcholine receptors on muscle cells grown

in vitro 781

289 Probing neuronal acetylcholine receptors with a—

bungaro toxin 782

290 The acetylcholine receptors of the nervous system in

Aplysia 783

291 Development of cell lines with neuronal properties 785

292 Development of cell lines expressing neuronal phenotypes by treating embryonic neuronal tissue with ethylnitro-

sourea 786

293 The storage and release of molecules required for synaptic communication 787

294 Ultrastructural investigation of the neuronal properties of somatic cell hybrids between neuroblastoma and other

cell types 788

295 Cell recognition and adhesion as early events in synapse formation 790

296 Glycolipids of neuroblastoma and neuroblastoma x glioma

hybrid cells 791

297 Dissociated cell culture assay of nerve growth factor 792

298 Neural models for a two dimensional nerve net 793

299 Chemistry and function of microtubules 795

300 A general method for mapping mammalian genes using somatic

cell hybrids 797

301 Development of an in vitro model of the Lesch-Nyhan

Syndrome 798

302 Genetic analysis of A particles using somatic cell hybrids- 799

303 Genetic analysis of adenosine 3',5'-cyclic monophosphate

(cAMP) in mammalian cells 800

304 Disseminated intravascular coagulation 801

305 Genetic analysis of differentiated functions using somatic

cell hybrids 803

306 The biology of cyclic AMP in E. coli 804

307 Mechanisms in protein synthesis 806

308 Cultured cell systems for neurobiology 808

309 A histof luorescence study of cultured chromaffin cells 810

ANNUAL REPORT OF THE CARDIOLOGY BRANCH NATIONAL HEART AND LUNG INSTITUTE July 1, 1972 through June 30, 1973

The experimental interests of the Cardiology Branch developed over the past few years have continued. These relate to the pathogenesis, pathophysiology, and treatment of coronary artery disease; the ultras true tural and molecular mechanisms responsible for impaired contractile function of the heart; the de- velopment of the potential capabilities of echocardiography; and the applica- tion of echocardiographic and electron microscopic techniques to define the basic developmental pathophysiology, genetics, and epidemiology of asymmetric septal hypertrophy, or ASH (idiopathic hypertrophic subaortic stenosis).

CORONARY ARTERY DISEASE

Mechanisms of Sudden Death and Pharmacologic Treatment of Acute Myocardial Infarction

I) Atropine in Acute Myocardial Infarction. Approximately 60% of deaths caused by acute myocardial infarction (AMI) occur within the first two hours of onset of symptoms and before medical aid arrives. Since bradycardia 1) oc- curs in a high percentage of patients seen soon after the onset of AMI, and 2) is believed to predispose to the development of ventricular ectopic rhythms and ventricular fibrillation (VF) , it has been suggested that a substantial decrease in the number of prehospital arrhythmic deaths would result if atro- pine were administered shortly after onset of ischemic pain in patients with bradycardia. We have performed several studies to test this hypothesis.

1) When AMI is produced in conscious closed-chest dogs by inflation of a balloon cuff previously implanted around the left anterior coronary artery (LAD), arrhythmias, including VF, tend to develop more frequently in dogs treat- ed with atropine than in randomly selected control dogs. We also found that the type of ventricular ectopic beats occurring during the early phase of AMI in dogs can be characterized as malignant arrhythmias (those that when present often lead to VF and death) and benign arrhythmias (those that never are asso- ciated with the eventual development of VF) . Using this information, we demon- strated that while benign arrhythmias are successfully suppressed by increasing heart rate with either atropine or atrial pacing, these interventions rarely abolish malignant arrhythmias. We next determined the influence of pronounced and persistent bradycardia, produced by vagal stimulation, on the incidence of benign and malignant arrhythmias during AMI. In the same closed-chest dog prep- aration heart rate was held between 80 and 100 beats /min in the control group and between 40 and 60 in the bradycardia group. Our findings demonstrated that the overall incidence of arrhythmias as well as the incidence of malignant ar- rhythmias was not increased by bradycardia during AMI. Moreover, when arrhyth- mias occurred in the bradycardia group, they were more short-lived, with sig- nificantly fewer arrhythmias present 45 minutes after AMI in the bradycardia as compared to the normal heart rate dogs. Thus a) bradycardia appears to ex- ert a favorable influence on the incidence of ventricular arrhythmias during experimental AMI, b) increasing heart rate with atropine tends to have a dele- terious effect on arrhythmias, c) not all ventricular arrhythmias are potenti-

ally lethal, and d) interventions may have very different effects on benign and malignant arrhythmias, a finding indicating that the clinical efficacy of antiarrhythmic drugs cannot be based on the assumption that a decrease in over- all arrhythmia incidence is equivalent to a reduction in mortality.

2) Additional studies were designed to determine the mechanisms responsible for the apparent protective effects of bradycardia and deleterious effects of increasing heart rate on serious ventricular arrhythmias during AMI.

a) First, we found a highly significant direct correlation between per cent increase in heart rate produced by atropine and per cent increase in is- chemic injury (as determined by ST segment elevation recorded from intramyo- cardial electrodes) over a heart ratf range of 30 to 180 beats/min. This find- ing indicates that the increase in MVO2 produced by a faster rate is sufficient to unfavorably alter the critical balance between myocardial oxygen demand and supply, thereby producing increased ischemia.

b) Previous studies from other laboratories showed that bradycardia and that acute myocardial ischemia lower VF threshold and increase disparity of myocardial refractory periods, findings indicating diminished electrial stabil- ity and leading to the now commonly accepted concept that increasing heart rate during AMI protects against serious ventricular arrhythmias. However, the elec- trophysiologic effects of a faster heart rate during AMI were not explored, an important omission since elevating heart rate during AMI increases the degree of ischemic injury. We thus measured VF threshold and disparity of refractory periods during AMI in open-chest dogs. As we suspected, fibrillation threshold was lower at faster heart rates and disparity of refractory periods was great- er. Thus, lower heart rates during AMI lead to electrophysiologic changes that protect against the development of serious ventricular arrhythmias. In addi- tion, we found that vagal stimulation per se, independent of changes in heart rate, enhanced electrical stability of the ventricle. This was an unexpected result, since it commonly is believed that vagal innervation of the ventricles is not physiologically important. To localize the cholinergic pathways respon- sible for this stabilizing electrophysiologic effect, vinblastine, a neurotoxic agent, was injected into the para-aortic area adjacent to the AV node. This area contains cholinergic ganglia that supply postganglionic fibers to the ven- tricle. Five to 7 days later, vagal stimulation caused atrial slowing but did not change VF threshold, signifying that vagal efferents to the atria were in- tact but those to the ventricle (responsible for increasing electrical stabil- ity) were functionally inoperative. The anatomic correlate of this electro- physiologic finding was obtained by studying the morphologic relationship of the ventricular conducting system and cholinergic nerves within the ventricu- lar septum. In control dogs Purkinje fibers were encapsulated by numerous cholinergic nerves. However, few cholinergic fibers were found in vinblastine treated dogs. We conclude that 1) stimulation of the vagus nerve decreases vulnerability of the ventricle to fibrillation, and 2) this action is mediated by a rich network of cholinergic nerves intimately related to Purkinje fibers

in the ventricular septum.

3) To determine whether the electrophysiologic effects of vagal stimulation are of functional significance, the incidence of VF is being assessed in dogs with and without vagal stimulation during 30 min of LAD occlusion. In one

series of experiments heart rate is allowed to slow in the vagally stimulated dogs. While 87% of the control dogs have fibrillated after 30 minutes of AMI, only 407o of the vagally treated dogs have. Moreover, when heart rate is held constant (to assess the effects of vagal stimulation per se ) , 88% of control dogs have developed VF during coronary occlusion, vihile only 45% of the vagally stimulated dogs have.

II, Nitroglycerin and Acute Myocardial Infarction. Nitroglycerin (TNG) gen- erally is believed contraindicated in the treatment of AMI because of the po- tential deleterious effects of a decrease in blood pressure (and thereby coro- nary perfusion pressure) and reflex increase in heart rate. If TNG dilates coronary collateral vessels, however, its net effect may be beneficial. We have now completed several studies, the results of which suggest that TNG may favorably alter the course of AMI.

1) We first demonstrated that hypotension, either reflexly induced (by stim- ulating the carotid baroreceptors) or induced by hemorrhage, increases the de- gree of ischemic injury occurring during AMI. In contrast, when identical lev- els of hypotension are produced by TNG, the degree of ST elevation (and presum- ably, the degree of ischemia) is reduced during 15 minutes of coronary occlu- sion. Moreover, v^en arterial pressure is held constant by simultaneous infu- sion of the alpha receptor agonists methoxamine or phenylephrine, the current of injury is reduced further. To confirm that the beneficial action on ST seg- ments reflects a decrease in myocardial ischemia, another series of randomly treated closed-chest dogs was studied. In these animals the effects of TNG and methoxamine on development of myocardial infarction was examined after 5 hrs of coronary occlusion. Ten minutes after onset of occlusion, ST elevation was measured in each of several previously implanted intramyocardial electrodes, and dogs were randomized into control and treated groups. Treated dogs received iv TNG during the remainder of the 5 hr occlusion, and arterial pressure was maintained at preinfusion levels with iv methoxamine. Six of 13 control dogs died; 2 of 14 treated dogs died. After 24 hours severity of infarct was as- sessed in survivors by measurement of creatine phosphokinase (CPK) content of myocardium subjacent to each electrode. In controls, a significant reduction

in CPK occurred in 48 of 57 electrode sites where ST elevation was present af- ter 10 minutes of occlusion. Only 19 of 69 such sites showed significant CPK reduction in treated dogs (p < .001). We conclude that in experimental coro- nary occlusion TNG reduces myocardial ischemia, an effect greatly potentiated by preventing the decrease in coronary perfusion pressure and reflex tachy- cardia with methoxamine.

2) It currently is believed that TNG does not significantly increase myocar- dial blood flow in patients with diseased coronary arteries. Thus, relief of angina pectoris by TNG is ascribed to a lowering of myocardial oxygen demands. The studies just presented, however, demonstrated that even when 2 of the more important determinants of myocardial oxygen consumption were held constant (arterial pressure and heart rate), TNG still reduced ischemic injury. There- fore, to determine \Aiether TNG can increase blood flow to ischemic regions, the capacity of coronary collaterals to supply blood to areas of potential ischemia was assessed before and after TNG in dogs in which MVO2 was held constant, and

in patients undergoing saphenous vein bypass surgery. In the animal experiments.

we found that whenever TNG reduced the current of injury recorded by epicardial electrodes after LAD occlusion, the reduction in ischemic injury always corre- lated with an increase in retrograde coronary flow, a measure of the capacity of the collaterals to supply blood to ischemic myocardium. In patients under- going coronary artery bypass operation, flow and pressure measurements were made from the distally (but not proximally) attached vein graft while the fi- brillating heart was sustained by cardiopulmonary bypass. Following TNG coro- nary collateral resistance fell. Thus, TNG can reduce ischemic injury during experimental AMI as a result of increased collateral flow. Moreover, TNG also is capable of diminishing resistance to collateral flow in man despite severe multivessel disease.

3) We next studied the electrophysiologic effects of TNG during AMI produced in the open-chest dog. VF threshold was measured during ischemia in the pres- ence and absence of TNG infusion, and during ischemia when phenylephrine was administered with TNG to maintain arterial pressure at control levels. We found that TNG enhanced electrical stability of the heart during AMI; moreover when arterial pressure was restored by simultaneous infusion of phenylephrine, VF threshold during AMI returned to control values.

4) Finally, a highly malignant model of AMI in dogs was developed to deter- mine whether the beneficial effects of TNG on ischemic injury, collateral re- sistance, and electrical stability could alter the incidence of VF and death during AMI. Twelve of 13 control dogs died from VF during 30 minutes of AMI; in contrast, only 7 of 14 dogs treated with TNG and methoxamine died (p < .05). As a result of these studies, we conclude that the long-standing clinical ca- veat not to administer TNG to patients with AMI may be in error; indeed, TNG may be uniquely valuable in the treatment of AMI, having the potential to di- minish ischemic injury and reduce the incidence of fatal arrhythmias.

Surgical Therapy of Coronary Artery Disease

Despite the enormous number of aorto-coronary bypass grafts being performed worldwide, little is known of the effects of operation on overall and regional myocardial function. We have studied 22 consecutive patients who underwent cardiac catheterization before and one week to 9 months after aorto-coronary bypass. We found that all patients, regardless of whether grafts were patent or occluded, improved clinically. In many angina was relieved totally. How- ever, overall LV performance deteriorated in 10 of these patients and improved in only one. In patients whose grafts were occluded, ejection fraction de- creased an average of 187o (p "^ .05). Twenty-eight LV wall segments were sup- plied by patent grafts; function improved in 6, was unchanged in 13, and dete- rioBted in 9. Twenty-two segments were supplied by occluded grafts; none im- proved, 14 were unchanged, and 8 deteriorated. We conclude that regardless of graft patency, most patients improve clinically. Despite this, deterioration of myocardial function