title: Density-dependent regulation of growth of BSC-1 cells in cell culture: growth inhibitors formed by the cells.
abstract: Inhibitors formed by a monkey epithelial cell line, BSC-1, play an important role in limiting growth at high cell densities. At least three inhibitors are formed: lactic acid, ammonia, and an unidentified inhibitor that may be an unstable protein. The unidentified inhibitor is destroyed by shaking the conditioned medium, by bubbling gas through the medium, or by heating or storing the medium in the absence of cells. The concentrations of lactic acid and ammonia that accumulate in conditioned medium inhibit growth when added to fresh medium. These results, together with earlier studies, indicate that density-dependent regulation of growth of BSC-1 cells results from the combined effects of (a) inhibitors formed by the cells, (b) decreased availability of receptor sites for serum growth factors as the cells become crowded, and (c) limiting concentrations of low molecular weight nutrients in the medium. In contrast, density-dependent regulation of growth in 3T3 mouse embryo fibroblasts results almost entirely from inactivation of serum factors.
mesh_terms: D000641:Ammonia / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects*; D002460:Cell Line; D003260:Contact Inhibition; D003470:Culture Media; D004848:Epithelium / Q000254:growth & development; D007773:Lactates / Q000494:pharmacology; D013997:Time Factors
chemical_list: D003470:Culture Media; D007773:Lactates; D000641:Ammonia
references.citation: J Immunol. 1963 Sep;91:416-24
references.pmid: 14071033
references.citation: Proc Natl Acad Sci U S A. 1977 Nov;74(11):5046-50
references.pmid: 303774
references.citation: Nature. 1977 Jun 16;267(5612):623-5
references.pmid: 141620
references.citation: Proc Natl Acad Sci U S A. 1978 Jan;75(1):339-41
references.pmid: 272650
references.citation: J Cell Physiol. 1971 Dec;78(3):333-44
references.pmid: 5003705
references.citation: Nature. 1970 Aug 22;227(5260):802-6
references.pmid: 4317354
references.citation: Int Rev Cytol. 1975;42:1-47
references.pmid: 127756
references.citation: Nature. 1973 Nov 23;246(5430):200-3
references.pmid: 4586793
references.citation: Nature. 1973 Nov 23;246(5430):197-9
references.pmid: 4586792
references.citation: Proc Natl Acad Sci U S A. 1974 Jul;71(7):2908-11
references.pmid: 4527719
references.citation: Proc Natl Acad Sci U S A. 1975 Jan;72(1):214-8
references.pmid: 1054496
references.citation: In Vitro. 1970 Sep-Oct;6(2):89-108
references.pmid: 5523183