The antihypertensive effect of acute intracerebroventricular administration of captopril in Dahl salt-sensitive rats.
The ability of centrally administered angiotensin converting enzyme (ACE) inhibitors to lower mean arterial pressure (MAP) has been demonstrated in numerous animal models of hypertension. In the present study, we assessed the effect of intracerebroventricular (i.c.v.) injection of the ACE inhibitor captopril (10 micrograms) on MAP in conscious, freely moving hypertensive inbred Dahl salt-sensitive (DS/JR) rats and their normotensive control inbred Dahl salt-resistant (DP/JR) rats. Both DS/JR and DR/JR rats were maintained on an 8% salt diet from 4 weeks of age until experimentation at 7-8 weeks of age, at which time DS/JR pressures were significantly elevated as compared to DR/JR rats (185 +/- 6 vs. 99 +/- 2 mm Hg, respectively). Following i.c.v. administration of captopril, a significant depressor response lasting for several hours was observed in DS/JR rats, with a maximum reduction of 17.6 +/- 4.1 mm Hg. The same treatment had no effect on the MAP of DR/JR rats. Mean arterial pressures in both groups were not significantly affected by i.c.v. administration of vehicle alone or by intravenous (i.v.) administration of 100 micrograms of captopril. These findings indicate that i.c.v. captopril lowers MAP in hypertensive DS/JR rats. Further studies will be necessary to elucidate the mechanism of this antihypertensive effect.
Lark
L A
LA
Neuroscience Program, University of Illinois, Urbana 61801.
Weyhenmeyer
J A
JA
D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002216:Captopril / Q000008:administration & dosage / Q000494:pharmacology*; D006973:Hypertension / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D007276:Injections, Intraventricular; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012965:Sodium Chloride
D000959:Antihypertensive Agents; D012965:Sodium Chloride; D002216:Captopril