Mechanisms of the effects of vasopressin on plasma levels of free fatty acids and triglycerides in pygmy goats.

1. Intraperitoneal injection of vasopressin (VP, 0.4 or 0.75 microgram/kg body wt) produced a decrease in plasma free fatty acids (FFA) and an increase in plasma triglyceride (TG) levels in pygmy goats. 2. These effects were not attenuated by prior or co-injection of a vasopressin antagonist with a selective affinity to V1-receptors. 3. A vasopressin antagonist with predominant affinity to V2-receptors prevented vasopressin's effect on plasma lipid levels whereas a V2-receptor agonist did not significantly influence plasma lipids. 4. The effect of vasopressin on plasma lipids in pygmy goats therefore seems to be mediated by receptors being neither identical with V1- or V2-receptors.