Influence of Histamine on Electrolyte and Water Handling of the Canine Kidney

Abstract

Summary

Intra-arterial infusion of hista-mine results in dose-related increases in RBF, while GFR remains constant, resulting in progressive decrease in FF. Renal extraction of PAH (E _pah) decreased reciprocally with RBF, possibly a result of enhanced plasma flow rates. MABP remained quite stable. Increase in minute urine volume (V _u), and fractional clearance (fC) of Na⁺, K⁺, Ca²⁺, and osmality appeared to be related to the increments in blood flow, while simultaneous decrements in fT ^c _h20 and U/P_Osm occurred. The physical factors hypothesis could account for the observed changes in urine volume and electrolyte clearance, but other factors must also be considered, such as loss of nephron-concen-trating ability because of washout of the gradient of osmolality, a possible direct effect of histamine on the collecting duct H₂O permeability, or inhibition of ADH action.

This investigation was supported by National Science Foundation Grant PCM 76-04368. We are indebted to Dr. Myron H. Weinberger, Specialized Center of Research in Hypertension (Grant HL-14159), Indiana University School of Medicine, for assistance.