The importance of aerobic metabolism in the renal concentrating process

Edward Weinstein; Andrzej Manitius; Franklin H. Epstein

doi:10.1172/JCI106151

The importance of aerobic metabolism in the renal concentrating process

Edward Weinstein, Andrzej Manitius, and Franklin H. Epstein

Published October 1, 1969 - More info

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Abstract

The extent to which the concentrating function of the kidney depends on oxidative processes was investigated by infusing cyanide into one renal artery of dogs undergoing mild mannitol diuresis while receiving an infusion of vasopressin. This produced an abrupt fall in concentrating capacity (T^c_H₂O) that was reversed when the cyanide infusion was stopped. The change could not be accounted for by the accompanying solute diuresis, since it was not reproduced by increasing the rate of mannitol infusion. The reduction in T^c_H₂O induced by cyanide did not result from increased delivery of dilute urine to the collecting ducts, since free water clearance (C_H₂O), studied in other dogs during water diuresis, was unchanged or decreased by cyanide. Cyanide produced renal vasodilatation, as did intraarterial acetylcholine, but in contrast to the striking reduction in concentrating capacity evoked by cyanide, T^c_H₂O was not significantly changed by acetylcholine.

The data indicate that concentrating ability is closely tied to oxidative metabolism in the kidney, and it is suggested that the region where this is critically important is the red medulla and the thick ascending limb of Henle's loop.