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Updated: Jun 17, 2026

Estimation of Nephron Number in Whole Kidney using the Acid Maceration Method
Published on: May 22, 2019
Urinary concentration and dilution in the aging kidney
1Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA. jsands@emory.edu
Abstract:
Aged people and rats have a reduced ability to maximally concentrate their urine. Many of the key transport proteins that contribute to urine concentrating ability are reduced in the medulla of aged rats. The reductions in the abundances of water, sodium, and urea transport proteins, and their reduced response to water restriction, contributes to the reduced ability of aged rats to concentrate their urine and conserve water. If similar mechanisms occur in human kidneys, it would provide a molecular explanation for the reduced concentrating ability in aging and may provide opportunities for novel therapeutic approaches to improve urine concentrating ability.
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