The effect of simultaneous administration of levarterenol and phentolamine on renal blood flow.

The effect of simultaneous administration of levarterenol and phentolamine upon renal blood flow was studied over a 3-hour period in 22 mongrel dogs. The infusion of levarterenol alone produced a fall in renal blood flow that ranged from 28 to 58% from the baseline value. When both drugs were administered simultaneously, renal flow fell only 17 to 22% from baseline (p less than 0.05). From these studies we conclude that the simultaneous administration of levarterenol and phentolamine in optimal ratios maintains renal blood flow near baseline levels.