Q. Describe about coronary reactive hyperemia?
Myocardium depends almost completely on aerobic metabolism. Occlusion of a coronary artery even briefly produces an increase in coronary blood flow above baseline, immediately following release of the occlusion. This response is called coronary reactive hyperemia. The potential mediators of this are adenosine, other nucleotides, NO, PG, CO2 and H+. Adenosine plays a significant role in the regulation of coronary blood flow during reactive hyperemia, hypoxia, inotropic stimulation with isoproterenol, dobutamine and mental stress. Other vasodilators involved in metabolic regulation of coronary flow are NO and prostanoids.