Ethanol increases plasma vasopressin shortly after intraperitoneal injection in rats

In rats, ethanol has generally been thought to inhibit vasopressin (VP) release into the peripheral circulation; however, the primary evidence for this conclusion has been indirect. Radioimmunoassay was used to measure VP in the plasma of rats decapitated 5 or 60 min after intraperitoneal injection of ethanol (2.0 g/kg). Confirming the popular notion that ethanol inhibits VP release, VP levels were decreased 60 min after treatment. But radioimmunoassay techniques also revealed that VP release is markedly stimulated shortly after an injection of ethanol.