Effects of dopamine on renal receptors for arginine vasopressin

To determine whether dopamine would affect the arginine vasopressin (AVP) receptors in the kidney, and if so, which source of dopamine would predominantly affect them, changes in the AVP receptors of the rat kidney were measured under the conditions of chronic renal denervation and the chronic infusion of dopamine using the radiolabeled receptor assay (RRA) of [³H]-AVP. Denervation was performed by stripping the nerves from the renal artery and coating them with 10% phenol. Chronic denervation had no significant effect on either the affinity or maximum binding capacity of the renal AVP receptors, although diuresis was observed. The chronic infusion of dopamine using an osmotic minipump produced a decrease in the affinity of the AVP receptors. These observations indicate that dopamine may regulate the AVP receptors in rat kidney via circulating dopamine.