Reduced content of vasopressin in the brain of spontaneously hypertensive as compared to normotensive rats.

Arginine-vasopressin (AVP) content was measured by radioimmunoassay in the plasma and brain of stroke-prone spontaneously hypertensive rats (SHRsp) and normotensive Wistar Kyoto (WKY) control rats. AVP was reduced in plasma, hypothalamus, amygdala, septum and brain stem of the hypertensive animals. In view of the possible sensitizing effect of vasopressin on the baroreceptor reflex, the reduction of this peptide in the brain stem could contribute to hypertension in SHRsp.