Augmentation of peritoneal mass transport by dopamine: comparison with norepinephrine and evaluation of pharmacologic mechanisms.

The effect of catecholamines on transport during peritoneal dialysis was studied in unanesthetized rabbits. Intravenous I-norepinephrine consistently decreased peritoneal clearances of urea and creatinine to 84% of control values or less but did not affect osmotically induced water flux. Comparable pressor doses of dopamine increased clearances of urea and creatinine to 145% of control values, whereas osmotic fluid flux increased only slightly. Dopamine also increased urea transport when administered intraperitoneally. The augmentation of solute transport by dopamine was unaffected by simultaneous administration of propranalol, was decreased by phentolamine, and was abolished by haloperidol. Dopamine may be preferable toI-norepinephrine when vasopressor therapy is required during peritoneal dialysis. The augmented transport with dopamine appears to depend on the action of dopamine receptors causing mesenteric vasodilation and in part on alpha-adrenergic receptors simultaneously increasing blood pressure while mesenteric blood flow is maintained.