title: NH4Cl and protein metabolism in human gingival fibroblasts.
abstract: The biologic effect of ammonia was studied in cultures of fibroblasts isolated from human gingiva, NH4Cl in the range 2-20 mM was found to exhibit a concentration dependent growth inhibitory effect, with a delayed action which was most pronounced at low concentrations. Concomitant with the growth inhibitory effect a significant cellular accumulation of protein was evident. No effects on protein synthesis in general, as measured by 14C-proline incorporation, was found, whereas some inhibitory effect on collagen biosynthesis was indicated. Secretion of 14C-collagen and other labeled proteins was not affected. The only pronounced effect of ammonia on metabolism of the 14C-labeled proteins was an inhibition of the intracellular degradation of newly synthesized collagen, the lysosomes being suggested as the site for this degradation.
mesh_terms: D000641:Ammonia / Q000008:administration & dosage / Q000494:pharmacology*; D000643:Ammonium Chloride / Q000494:pharmacology; D002452:Cell Count; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects*; D005881:Gingiva / Q000166:cytology*; D006801:Humans; D011506:Proteins / Q000378:metabolism*; D013997:Time Factors
chemical_list: D011506:Proteins; D000643:Ammonium Chloride; D000641:Ammonia; D003094:Collagen