Dopamine receptors in normal and diabetic liver plasma membrane.

Dopamine binding to liver plasma membrane isolated from diabetic livers was significantly reduced (P less than 0.01) as compared to dopamine binding to the normal membrane. Diabetic membranes exhibited a significant decrease (P less than 0.01) in specific dopamine binding as compared to the normal membranes; whereas no significant change (P less than 0.5) was noticed in the nonspecific binding patterns. The dopamine binding capacity of both membranes is temperature dependent. Procaine at different concentrations inhibited significantly (P less than 0.01) dopamine binding to normal and diabetic membranes. Treatment of the normal and diabetic membranes with insulin showed a 33% decrease in the binding capacity of the normal and 42% decrease in the binding capacity of the diabetic membrane.