Pheochromocytoma and myocardial infarction.

Pheochromocytomas are rare chromaffin cell tumors, 90% of which arise from the adrenal glands. Pheochromocytomas presenting with true myocardial infarction are even more rare. We report a 76-year-old man who had a previously undiagnosed pheochromocytoma, and presented with the uncommon complication of myocardial infarction.

Activation of ATP-sensitive potassium channels contributes to reactive hyperemia in humans.

Activation of ATP-sensitive potassium (KATP) channels present on vascular smooth muscle cells causes membrane hyperpolarization and vasodilation. The purpose of this study was to determine whether KATP channels contribute to reactive hyperemia in humans. Accordingly, we studied the effect of tolbutamide, a KATP channel inhibitor, on reactive hyperemic forearm blood flow.

Endothelial release of nitric oxide contributes to the vasodilator effect of adenosine in humans.

Background: The endogenous nucleoside adenosine plays an important role in the regulation of vascular tone, especially during ischemia. Experimental data derived from animal models suggest that nitric oxide (NO) contributes to the vasodilator effect of adenosine. The primary purpose of this investigation was to determine whether the endothelial release of NO contributes to adenosine-induced vasodilation in humans.

Myogenic and agonist induced responses of coronary venules after cold hyperkalaemic cardioplegia.

Objective: The aim was to examine agonist induced and myogenic venular responses after crystalloid cardioplegia in conditions simulating cardiopulmonary bypass.

Methods: Hearts of pigs were arrested with cold hyperkalaemic ([K+] = 25 mM) crystalloid cardioplegic solution for 1 h under conditions of cardiopulmonary bypass. In another group, hearts were arrested and then reperfused with warm blood for 1 h while being separated from cardiopulmonary bypass.