Enkephalin-containing polypeptide levels in normal tensive and SHR rat adrenal glands

The levels of enkephalin-containing polypeptides (ECPs) in the adrenal glands of normal tensive rats (WKY) and spontaneously hypertensive rats (SHR) were compared. Innervated and denervated adrenals from both types of rats showed very similar levels of ECPs. The only difference observed was a small increase in the 18 kdal ECP and a concomitant decrease in the 12 kdal and 5.3 kdal ECPs in the innervated SHR rat adrenal gland. From these data it appears that the adrenal ECPs are not a major contributor to hypertension in the SHR rat nor does hypertension, at this age, affect the ECP levels.