Ammonium chloride increases kidney cell protein content
Dahl, D.C.; Tsao, T.; Rabkin, R.
Mineral and Electrolyte Metabolism 18(2-5): 104-107
1992
ISSN/ISBN: 0378-0392 PMID: 1465042 Document Number: 400504
Augmented renal ammoniagenesis and renal hypertrophy often occur together. Ammonia may increase cell protein content by modulating protein synthesis, protein degradation, or both. We conducted experiments to examine the effect of ammonium chloride on the synthesis and degradation of protein in cultured kidney cells. Quiescent opossum kidney cells were exposed to 20 mM NH4Cl for two days. Monolayers were then analyzed for cell number, protein content, protein synthesis ([14C]valine incorporation), protein degradation ([14C]valine release) and DNA synthesis ([3H]thymidine incorporation). Cell protein content was increased by 18% in NH4Cl-treated cells (190 +/- 6 pg/cell control vs. 225 +/- 7 pg/cell NH4Cl, p < 0.001). NH4Cl suppressed protein degradation (1.36 +/- 0.02%/h control vs. 1.12 +/- 0.04%/h NH4Cl, p < 0.001) but did not change protein synthesis, DNA synthesis, or cell number. Thus, reduced protein degradation accounts entirely for enhanced protein accumulation at 2 days in this in vitro model of kidney cell hypertrophy.