EFFECT OF PENTOBARBITAL AND CHLORDIAZEPOXIDE ON THE CENTRAL PRESSOR ACTION OF ANGIOTENSINS IN NORMOTENSIVE AND HYPERTENSIVE RATS

Pentobarbital and chlordiazepoxide administered intracerebroventricula rly (i.c.v.) attenuated dose dependently the presser action of i.c.v. angiotensin II and angiotensin III in the conscious spontaneously hype rtensive rat (SHR) and the normotensive control Wistar Kyoto rat (WKY) . Attenuation of the presser action by the two drugs was more marked i n the WKY than in the SHR. Based on the fact that both drugs act via t he gamma-aminobutyric acid (GABA) receptors, the data support the sugg estions (i) that a central GABAergic system regulates blood pressure, (ii) that there is probable dysfunction of the GABA receptors in SHR.