Adrenal medulla as a mediator of diet-induced hypertension.

Male Sprague-Dawley rats fed either a high-fat or glucose-enriched diet for 10 wk developed higher blood pressure (BP) and higher urinary catecholamine excretion than rats fed a control diet. After 10 wk of diet treatment, systolic BP was 164 +/- 3, 156 +/- 2, and 145 +/- 4 mmHg in rats fed the high-fat, glucose, and control diets, respectively (P < 0.02 vs. control). During weeks 7-9 of diet treatment, excretion of epinephrine and norepinephrine was increased in hypertensive rats (those fed the high-fat or glucose diet) when compared with rats fed the control diet (P < 0.001). The purpose of this study was to determine whether the hypertensive response to nutrients could be prevented by prior surgical removal of the adrenal medulla. Adrenal demedullation nearly abolished epinephrine excretion, attenuated norepinephrine excretion, and completely blocked the hypertensive response to dietary fat and glucose. These findings suggest that adrenal medullary catecholamines play a role in the hypertensive response to nutrients.