Proximal Tubule Glutamine Synthetase Expression is Necessary for the Normal Response to Dietary Protein Restriction.

Proximal Tubule Glutamine Synthetase Expression is Necessary for the Normal Response to Dietary Protein Restriction. Am J Physiol Renal Physiol. 2017 Mar 22;:ajprenal.00048.2017 Authors: Lee HW, Osis G, Handlogten ME, Verlander JW, Weiner ID Abstract Dietary protein restriction has multiple benefits in kidney disease. Because protein intake is a major determinant of endogenous acid production, it is important that net acid excretion change in parallel during changes in dietary protein intake. Dietary protein restriction decreases endogenous acid production and ¬decreases urinary ammonia excretion, a major component of net acid excretion. Glutamine synthetase (GS) catalyzes the reaction of NH4+ and glutamate, which regenerates the essential amino acid glutamine and decreases net ammonia generation. Because renal proximal tubule GS expression increases during dietary protein restriction, this could contribute to the decreased ammonia excretion. The current study's purpose was to determine proximal tubule GS's role in the renal response to protein restriction. We generated mice with proximal tubule-specific GS deletion (PT-GS-KO) using Cre-loxP techniques. Cre-negative (Control) and PT-GS-KO mice in metabolic cages were provided 20% protein diet for 2 days and were then changed to low protein (6%) diet for the next 7 days. Additional PT-GS-KO mice were maintained on 20% protein diet. Dietary protein restriction caused a rapid decrease ...
Source: Am J Physiol Renal P... - Category: Urology & Nephrology Authors: Tags: Am J Physiol Renal Physiol Source Type: research