Regulation of coronary blood flow.
Regulation of coronary blood flow (CBF) is a complex process in which many neural, mechanical, myogenic and metabolic factors are involved and is largely controlled by local factors. Our recent results suggest that CBF and oxygen delivery to cardiac tissue is regulated according to the actual needs of the tissue, determined by oxygen consumption in the mitochondrial respiratory chain, controlled by the energy state of the cell. Several substances have been proposed to serve as messengers between the cardiac myocyte and the vascular smooth muscle cells. Abundant evidence has been accumulated showing that adenosine is an important regulator of CBF, its effects being thought to be mediated by binding to specific external or internal surface receptors, with regulatory link to adenylate cyclase. There is also evidence that adenosine formation takes place intracellularly, predominantly via a cytosolic 5'-nucleotidase. The intracellular level of adenosine is thought to be under delicate control by adenosine producing and metabolizing enzymes. Several arachidonic acid metabolites, especially prostacyclin, are also involved in the regulation of coronary circulation. The physiological significance of atrial natriuretic factor, which also seems to regulate CBF, cannot be established at this stage.
D000241:Adenosine / Q000378:metabolism / Q000502:physiology; D009320:Atrial Natriuretic Factor / Q000502:physiology; D003326:Coronary Circulation; D006439:Hemodynamics; D006706:Homeostasis; D006801:Humans; D008929:Mitochondria, Heart / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D011453:Prostaglandins / Q000502:physiology
D011453:Prostaglandins; D009320:Atrial Natriuretic Factor; D000241:Adenosine