Central effects of arginine vasopressin on blood pressure in rats

In anesthetized male Sprague-Dawley rats, intraventricular injection of 25-5000 pmol AVP caused short-latency, dose-related increases in blood pressure. Blood pressure increases occurred before any changes in urine flow were observed, suggesting that the AVP was acting centrally. Similar increases in blood pressure were observed after central AVP injection into homozygous Brattleboro rats which lack AVP, indicating these effects were not due to release of pituitary AVP stores. These results raise the possibility that endogenous AVP plays a role in the central control of blood pressure.