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

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