Abstract
(1) In spite of the existence of hypertension, PRC levels were not at all high in SHR B2, SHRSP and M-SHRSP with BP below 210mmHg. (2) PRC showed clear increases when BP did go over 210mmHg. (3) BP dropped to about 150mmHg upon administration of hydralazine hydrochloride but dropped only to around 210mmHg when renin-angiotensin system inhibitors such as saralasin or captopril were given. These findings suggest that plasma renin-angiotensin system are activated by extremely high BP levels of 210mmHg or more in SHRSP and M-SHRSP. This, in turn, may worsen the hypertension.
