Effects of bromocriptine on pituitary arginine vasopressin content in the segregating generation of the hybrid of spontaneously hypertensive and Wistar Kyoto rats

Abstract

Pituitary arginine vasopressin (AVP) content was determined by radioimmunoassay in bromocriptine (BRC)- and vehicle-treated male rats of the segregating F 2 generation of the hybrid of the spontaneously hypertensive rat (SHR) and the normotensive Wistar-Kyoto (WKY) control rat to see if there was any direct relationship between raised systolic blood pressure (SBP) and pituitary AVP content. The F 2 rats were divided into 3 groups: low SBP (<140 mmHg), intermediate SBP (140-160 mmHg) and high SBP (>160 mmHg). The pituitary AVP content in the BRC-treated group I rats was significantly higher than that in the vehicle-treated group I rats. There was no significant difference in the pituitary AVP content between the BRC- and vehicle-treated group II and group III rats. There was also no significant difference in the pituitary AVP content between the three groups of vehicle-treated rats either. The results suggest that AVP may not have a significant role to play in the hypertension of the SHR/WKY hybrid rats.