Adrenal medulla denervation prevents stress-induced epinephrine plasma elevation and cardiac hypertrophy

Circulating catecholamines have been proposed as trophic agents for the heart. Denervation of the adrenal medullae, the major source of plasma epinephrine, totally blocked left ventricular hypertrophy after aortic coarctation in the dog. The level of epinephrine after adrenal medullary cholinergic denervation dropped to a mean of 10 pg/ml within 48 hours compared to 317 pg/ml in coarcted dogs with intact adrenal innervation, and 116 pg/ml in sham-coarcted controls. Decreased epinephrine levels were concomitant with a decrease in the heart weight to body weight ratios. These data implicate epinephrine as the specific hormone regulating cardiac hypertrophy.