Biomaterial Database

Adrenergic control of transmural coronary blood flow. 1990

E O Feigl

Department of Physiology and Biophysics, University of Washington, Seattle.

Tachycardia and an increase in myocardial metabolism result from the sympathetic activation that occurs during baroreceptor reflexes, emotion, and exercise. Paradoxically, a concomitant adrenergic alpha-receptor-mediated coronary vasoconstriction competes with the local metabolic coronary vasodilation that occurs during these conditions, and thereby limits metabolic hyperemia. Measurements of transmural blood flow in alpha-receptor blocked and alpha-receptor intact regions of the left ventricle during exercise demonstrate that adrenergic vasoconstriction helps maintain blood flow to the vulnerable subendocardium during tachycardia. This may be the explanation as to why paradoxical adrenergic coronary vasoconstriction has evolved. During controlled conditions of constant coronary flow, an anti-transmural steal effect due to adrenergic vasoconstriction in the subepicardium can be demonstrated during ischemic conditions. These observations demonstrate unexpected beneficial effects of adrenergic coronary vasoconstriction during tachycardia and cardiovascular stress.

UI	MeSH Term	Description	Entries
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D011942	Receptors, Adrenergic, alpha	One of the two major pharmacological subdivisions of adrenergic receptors that were originally defined by the relative potencies of various adrenergic compounds. The alpha receptors were initially described as excitatory receptors that post-junctionally stimulate SMOOTH MUSCLE contraction. However, further analysis has revealed a more complex picture involving several alpha receptor subtypes and their involvement in feedback regulation.	Adrenergic alpha-Receptor,Adrenergic alpha-Receptors,Receptors, alpha-Adrenergic,alpha-Adrenergic Receptor,alpha-Adrenergic Receptors,Receptor, Adrenergic, alpha,Adrenergic alpha Receptor,Adrenergic alpha Receptors,Receptor, alpha-Adrenergic,Receptors, alpha Adrenergic,alpha Adrenergic Receptor,alpha Adrenergic Receptors,alpha-Receptor, Adrenergic,alpha-Receptors, Adrenergic
D001783	Blood Flow Velocity	A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.	Blood Flow Velocities,Flow Velocities, Blood,Flow Velocity, Blood,Velocities, Blood Flow,Velocity, Blood Flow
D003326	Coronary Circulation	The circulation of blood through the CORONARY VESSELS of the HEART.	Circulation, Coronary
D003327	Coronary Disease	An imbalance between myocardial functional requirements and the capacity of the CORONARY VESSELS to supply sufficient blood flow. It is a form of MYOCARDIAL ISCHEMIA (insufficient blood supply to the heart muscle) caused by a decreased capacity of the coronary vessels.	Coronary Heart Disease,Coronary Diseases,Coronary Heart Diseases,Disease, Coronary,Disease, Coronary Heart,Diseases, Coronary,Diseases, Coronary Heart,Heart Disease, Coronary,Heart Diseases, Coronary
D005082	Physical Exertion	Expenditure of energy during PHYSICAL ACTIVITY. Intensity of exertion may be measured by rate of OXYGEN CONSUMPTION; HEAT produced, or HEART RATE. Perceived exertion, a psychological measure of exertion, is included.	Physical Effort,Effort, Physical,Efforts, Physical,Exertion, Physical,Exertions, Physical,Physical Efforts,Physical Exertions
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014661	Vasoconstriction	The physiological narrowing of BLOOD VESSELS by contraction of the VASCULAR SMOOTH MUSCLE.	Vasoconstrictions