Excretion of Solutes Injected into the Renal Artery of the Dog

Abstract

Various solutes were injd. into one renal artery of a dog in such a way as to minimize interference with ipsilateral blood flow, at the time of the injn. Hypertonic saline, hyper- and hypotonic mannitol, 10% urea, hypertonic NaHCO3 and Na2HPO4 increased greatly the urine flow and the rate of Na excretion by the homolateral kidney, as compared with the opposite kidney. 25% albumin inconstantly decreased urine flow and the excretion of Na. Changes in the excretion of chloride were somewhat dependent on the nature of the injd. solute. It is concluded that the diuresis caused by the administration of hypertonic saline, urea, and NaHCO3 and by hyper- or hypotonic mannitol, is mediated at least in large part by a direct renal response to a change in the concn. of the solute in the blood perfusing the kidney. An hypothesis of the intrarenal mechanism involved in this response to injected solutes is offered.