Blood Pressure Responses of Conscious Normotensive and Spontaneously Hypertensive Rats

In conscious spontaneously hypertensive rats, intracerebroTentricular injection of captopril (2 rag/kg) resulted in a rapid hypotenshe response that lasted several hours. The same dose given by Intracerebroventricular injection had no significant effect on blood pressure (BP) of normotensive Wistar-Kyoto (WK) rats over 7 hours. There was no significant change in BP of conscious spontaneously hypertensive rats (SHR) in response to Intracerebroventricular injection of vehicle and only a transitory fall in BP in response to intravenous injection of captopril (2 mg/kg). There was no significant differences between plasma renin activity (PRA) of conscious norrootenslve WKY rats and the PRA of SHR. These results suggest biochemical differences between the brains of SHR and normotensive WKY control rats. These differences could involve the brain renin-angiotensin system or other iteuropeptides. (Hypertension 2: 546-550, 1980)