Many coronary stenoses are compliant and are capable of changes in caliber. Large coronary artery vasomotion caused by physiologic factors or by vasoactive drugs could have important effects on blood flow through compliant coronary stenoses. In this project, metabolic control and pharmacologic responses of large coronary artery caliber will be studied in chronically instrumented awake dogs using sonomicrometry. The effects of exercise on large coronary artery hemodynamics and diameter will also be studied. Studies will be done of passive changes in the resistance of compliant coronary stenoses in response to changes in intraluminal pressure in a dog model in which the diameter of the artery in the area of the stenosis will be measured. Studies will also be done concerning the responses of compliant coronary stenoses to vasoactive drugs and direct correlations will be made of changes in coronary arterial diameter, stenosis pressure gradient and blood flow through the stenotic artery. The proposed research is planned to contribute to our understanding of the mechanisms by which a coronary stenosis may lead to myocardial ischemia or infarction and to investigate how drugs modify the effects of severe coronary stenoses.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL031510-03
Application #
3342679
Study Section
Cardiovascular and Pulmonary Research B Study Section (CVB)
Project Start
1984-08-01
Project End
1987-07-31
Budget Start
1986-08-01
Budget End
1987-07-31
Support Year
3
Fiscal Year
1986
Total Cost
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Type
Schools of Medicine
DUNS #
168559177
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Canty Jr, J M; Schwartz, J S (1994) Nitric oxide mediates flow-dependent epicardial coronary vasodilation to changes in pulse frequency but not mean flow in conscious dogs. Circulation 89:375-84
Baran, K W; Bache, R J; Dai, X Z et al. (1992) Effect of alpha-adrenergic blockade with prazosin on large coronary diameter during exercise. Circulation 85:1139-45
Schwartz, J S; Baran, K W; Bache, R J (1990) Effect of stenosis on exercise-induced dilation of large coronary arteries. Am Heart J 119:520-4
Schwartz, J S; Bache, R J (1988) Effect of ouabain on large coronary artery diameter. J Cardiovasc Pharmacol 11:608-13
Schwartz, J S; Bache, R J (1988) Combined effects of calcium antagonists and nitroglycerin on large coronary artery diameter. Am Heart J 115:964-9
Bache, R J; Dai, X Z; Schwartz, J S et al. (1988) Role of adenosine in coronary vasodilation during exercise. Circ Res 62:846-53
Schwartz, J S (1987) Effect of nitroprusside-induced fall in systemic pressure on coronary stenoses. Int J Cardiol 14:15-24
Schwartz, J S; Bache, R J (1987) Effect of anesthesia on reactivity of large coronary arteries in the dog. J Cardiovasc Pharmacol 9:87-90
Schwartz, J S; Bache, R J (1985) Effect of arteriolar dilation on coronary artery diameter distal to coronary stenoses. Am J Physiol 249:H981-8