Constancy of Sodium Excretion in the Presence of Chronically Altered Glomerular Filtration Rate

Abstract

Hypophysectomized dogs with chronically low glomerular filtration rates, untreated or supported by sufficient desoxycorticosterone to replace any possible deficit of adrenal salt regulating hormones, remain in Na balance. Raising the filtration rates of hypophysectomized dogs to normal or above, or those of normal dogs to supranormal levels, by growth hormone administration causes no increase in Na excretion. These findings support the view that even marked alterations in glomerular filtration rate do not produce chronic Na imbalance in the presence of normal tubular absorptive behavior toward Na.