Skip to main content
NCBI home page
The Journal of Cell Biology logoLink to The Journal of Cell Biology
. 1971 Dec 1;51(3):686–702. doi: 10.1083/jcb.51.3.686

pH AND POPULATION DENSITY IN THE REGULATION OF ANIMAL CELL MULTIPLICATION

H Rubin 1
PMCID: PMC2108048  PMID: 4331502

Abstract

Sparse and dense cultures of chick embryo cells were affected differently by pH. The rates of cell multiplication and of thymidine-3H incorporation into DNA of dense cultures were increased as the pH was increased from 6.6 to 7.6. At pH higher than 7.6 the rate of multiplication decreased slightly in the dense cultures, but the rate of thymidine-3H incorporation continued to increase. The discrepancy was due in part to cell death and detachment at very high pH, and in part to a more rapid uptake of thymidine-3H at very high pH. Sparse cultures were much less sensitive to pH reduction and, when a suitably conditioned medium was used to minimize cell damage, very sparse cultures grew almost as well at pH 6.7 as at higher pH. The rates of cell multiplication and thymidine-3H incorporation at low pH decreased in the initially sparse cultures before they reached confluent cell densities. There was no microscope evidence of direct contact between plasma membranes of cells at these densities although the parallel orientation indicated that the cells were influencing locally each other's behavior. Even at much higher cell densities, electron microscopy revealed large intercellular gaps partly filled with a fragmentary electron-opaque material suspected to be glycoprotein. Wounding experiments showed that pH affected cell migration in a manner similar to its effects on cell multiplication. Low pH inhibited cell migration, but those cells which migrated into the denuded region multiplied as rapidly at low pH as at high pH. The effects of pH on growth were correlated with effects on the uptake of 2-deoxyglucose-3H. Dense populations of cells inhibited by low pH were stimulated to incorporate thymidine-3H by the addition of small amounts of diethylaminoethyl-dextran. Rous sarcoma cells at high cell density were less sensitive to pH than were normal cells at the same density, but were more sensitive than sparse normal cultures. The results suggest that cell growth is inhibited through the combined effects of both lowered pH and high cell density on cell surface permeability.

Full Text

The Full Text of this article is available as a PDF (1.3 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. ABERCROMBIE M., HEAYSMAN J. E., KARTHAUSER H. M. Social behaviour of cells in tissue culture. III. Mutual influence of sarcoma cells and fibroblasts. Exp Cell Res. 1957 Oct;13(2):276–291. doi: 10.1016/0014-4827(57)90007-1. [DOI] [PubMed] [Google Scholar]
  2. Castor L. N. Flattening, movement and control of division of epithelial-like cells. J Cell Physiol. 1970 Feb;75(1):57–64. doi: 10.1002/jcp.1040750107. [DOI] [PubMed] [Google Scholar]
  3. Ceccarini C., Eagle H. pH as a determinant of cellular growth and contact inhibition. Proc Natl Acad Sci U S A. 1971 Jan;68(1):229–233. doi: 10.1073/pnas.68.1.229. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Gail M. H., Boone C. W. Density inhibition of motility in 3T3 fibroblasts and their SV40 transformants. Exp Cell Res. 1971 Jan;64(1):156–162. doi: 10.1016/0014-4827(71)90206-0. [DOI] [PubMed] [Google Scholar]
  5. Hutter O. F., Warner A. E. The pH sensitivity of the chloride conductance of frog skeletal muscle. J Physiol. 1967 Apr;189(3):403–425. doi: 10.1113/jphysiol.1967.sp008176. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. PAUL J. Environmental influences on the metabolism and composition of cultured cells. J Exp Zool. 1959 Oct-Dec;142:475–505. doi: 10.1002/jez.1401420122. [DOI] [PubMed] [Google Scholar]
  7. Rein A., Rubin H. Effects of local cell concentrations upon the growth of chick embryo cells in tissue culture. Exp Cell Res. 1968 Mar;49(3):666–678. doi: 10.1016/0014-4827(68)90213-9. [DOI] [PubMed] [Google Scholar]
  8. Rubin H. A VIRUS IN CHICK EMBRYOS WHICH INDUCES RESISTANCE IN VITRO TO INFECTION WITH ROUS SARCOMA VIRUS. Proc Natl Acad Sci U S A. 1960 Aug;46(8):1105–1119. doi: 10.1073/pnas.46.8.1105. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Rubin H. A substance in conditioned medium which enhances the growth of small numbers of chick embryo cells. Exp Cell Res. 1966 Jan;41(1):138–148. doi: 10.1016/0014-4827(66)90554-4. [DOI] [PubMed] [Google Scholar]
  10. Rubin H., Colby C. Early release of growth inhibition in cells infected with Rous sarcoma virus. Proc Natl Acad Sci U S A. 1968 Jun;60(2):482–488. doi: 10.1073/pnas.60.2.482. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Rubin H. Overgrowth-stimulating activity of disrupted chick embryo cells and cells infected with Rous sarcoma virus. Proc Natl Acad Sci U S A. 1970 Nov;67(3):1256–1263. doi: 10.1073/pnas.67.3.1256. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Sefton B. M., Rubin H. Release from density dependent growth inhibition by proteolytic enzymes. Nature. 1970 Aug 22;227(5260):843–845. doi: 10.1038/227843a0. [DOI] [PubMed] [Google Scholar]
  13. Tasaki I., Singer I., Takenaka T. Effects of internal and external ionic environment on excitability of squid giant axon. A macromolecular approach. J Gen Physiol. 1965 Jul;48(6):1095–1123. doi: 10.1085/jgp.48.6.1095. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Vasiliev J. M., Gelfand I. M., Domnina L. V., Rappoport R. I. Wound healing processes in cell cultures. Exp Cell Res. 1969 Jan;54(1):83–93. doi: 10.1016/0014-4827(69)90296-1. [DOI] [PubMed] [Google Scholar]
  15. WEISS P., SCOTT B. I. POLARIZATION OF CELL LOCOMOTION IN VITRO. Proc Natl Acad Sci U S A. 1963 Aug;50:330–336. doi: 10.1073/pnas.50.2.330. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Winzler R. J. Carbohydrates in cell surfaces. Int Rev Cytol. 1970;29:77–125. doi: 10.1016/s0074-7696(08)60033-9. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of Cell Biology are provided here courtesy of The Rockefeller University Press

RESOURCES