Changes of plasma renin activity following intracerebroventricular administration of biologically active peptides in two-kidney, one clip hypertensive rats.
We studied the effects of intracerebroventricular (ICV) administration of angiotensin II (ANG II), bradykinin (BK), leucine-enkephalin (Leu-ENK) and neurotensin (NT) on plasma renin activity (PRA), blood pressure and heart rate in acute (less than 4 weeks) and chronic (more than 12 weeks) two-kidney, one clip (2K-1C) hypertensive rats. These four peptides all produced pressor responses. The pressor responses caused by ICV injection of ANG II, BK, Leu-ENK and NT in hypertensive rats did not differ significantly from the response in normal rats. In both acute and chronic 2K-1C hypertensive rats, ANG II and BK significantly suppressed PRA, NT did not affect PRA, and Leu-ENK produced a significant increase in PRA followed by a significant decrease in PRA. As compared to normal rats, suppression of PRA by ANG II and NT was attenuated or abolished but BK and Leu-ENK produced significant reductions in PRA in 2K-1C hypertensive rats. The results indicate that the effects of these four centrally administered peptides on blood pressure, heart rate and PRA in acute and chronic 2K-1C hypertensive rats were not essentially different from those in normal rats.
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001920:Bradykinin / Q000494:pharmacology*; D004743:Enkephalin, Leucine / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D006978:Hypertension, Renovascular / Q000097:blood*; D007276:Injections, Intraventricular; D008297:Male; D009496:Neurotensin / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012083:Renin / Q000097:blood*
D000804:Angiotensin II; D009496:Neurotensin; D004743:Enkephalin, Leucine; D012083:Renin; D001920:Bradykinin