EFFECTS OF HYPERTENSION AND HYPERCHOLESTEROLEMIA ON VASODILATION IN THE RABBIT

Abstract

Vasodilator substances act either directly on vascular smooth muscle (e.g., adenosine) or indirectly (e.g., acetylcholine) on endothelial cells that respond by releasing an unknown powerful, short-lived relaxing factor. To determine whether chronic hypertension or hypercholesterolemia or both would alter the release of the endothelium-derived relaxing factor, experiments were performed in hypertensive rabbits (5-week cellophane wrap perinephritis; mean blood pressure, 134.7 mm Hg) and normotensive rabbits (mean blood pressure, 80 mm Hg) with a Doppler flow transducer and perivascular balloon implanted on the lower abdominal aorta. Rabbits were fed either 1% cholesterol or control diet for 4 ..