Skip to main content
NCBI home page
Environmental Health Perspectives logoLink to Environmental Health Perspectives
. 1979 Dec;33:37–44. doi: 10.1289/ehp.793337

Intestinal transport: studies with isolated epithelial cells

George A Kimmich
PMCID: PMC1638117  PMID: 540624

Abstract

Isolated intestinal epithelial cells have been extremely useful for characterizing the nature of intestinal absorption processes and for providing insight into the energetics of Na+-dependent transport systems. This report describes a number of experimental approaches which have been used for investigating the specific epithelial transport systems involved in sugar absorption, but provides information which ultimately should prove useful for characterizing a number of different intestinal transport events. Similar experiments should also prove useful for exploring the effect of environmental agents on the function of intestinal tissue.

In the case of sugars, net absorption is accomplished via a mucosal, Na+-dependent concentrative transport system acting in sequence with a passive serosal system which does not require Na+. The serosal system limits the full gradient-forming capability of the muscosal system. Agents such as phloretin or cytochalasin B which inhibit serosal transport allow the cells to establish sugar gradients as high as 70 fold in contrast to 10-15 fold gradients observed for control cells. Seventy-fold sugar gradients cannot be explained in terms of the energy available in the electrochemical potential for Na+ if the Na+:sugar coupling stoichiometry is 1:1 as commonly assumed. New information indicates that the true Na+:sugar stoichiometry is in fact 2:1. Flow of two Na+ ions per sugar molecule down the transmembrane electrochemical potential for Na+ provides more than sufficient energy to account for observed 70 fold sugar gradients. If flow of sugar by other routes could be completely inhibited, theoretical sugar gradients as high as 400 could be achieved assuming that the cells maintain a membrane potential of −36 mV as measured for intact tissue.

Full text

PDF
37

Selected References

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

  1. ANAST C., KENNEDY R., VOLK G., ADAMSON L. IN VITRO STUDIES OF SULFATE TRANSPORT BY THE SMALL INTESTINE OF THE RAT, RABBIT, AND HAMSTER. J Lab Clin Med. 1965 Jun;65:903–911. [PubMed] [Google Scholar]
  2. Berner W., Kinne R., Murer H. Phosphate transport into brush-border membrane vesicles isolated from rat small intestine. Biochem J. 1976 Dec 15;160(3):467–474. doi: 10.1042/bj1600467. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Curran P. F., Schultz S. G., Chez R. A., Fuisz R. E. Kinetic relations of the Na-amino acid interaction at the mucosal border of intestine. J Gen Physiol. 1967 May;50(5):1261–1286. doi: 10.1085/jgp.50.5.1261. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Goldner A. M., Schultz S. G., Curran P. F. Sodium and sugar fluxes across the mucosal border of rabbit ileum. J Gen Physiol. 1969 Mar;53(3):362–383. doi: 10.1085/jgp.53.3.362. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Hopfer U. INtestinal sugar transport: studies with isolated plasma membranes. Ann N Y Acad Sci. 1975 Dec 30;264:414–427. doi: 10.1111/j.1749-6632.1975.tb31500.x. [DOI] [PubMed] [Google Scholar]
  6. Kimmich G. A., Carter-Su C. Membrane potentials and the energetics of intestinal Na+-dependent transport systems. Am J Physiol. 1978 Sep;235(3):C73–C81. doi: 10.1152/ajpcell.1978.235.3.C73. [DOI] [PubMed] [Google Scholar]
  7. Kimmich G. A. Preparation and properties of mucosl epithelial cells isolated frmsmall intestine of the chicken. Biochemistry. 1970 Sep 15;9(19):3659–3668. doi: 10.1021/bi00821a003. [DOI] [PubMed] [Google Scholar]
  8. Kimmich G. A., Randles J. 2-Deoxyglucose transport by intestinal epithelial cells isolated from the chick. J Membr Biol. 1976 Jun 30;27(4):363–379. doi: 10.1007/BF01869146. [DOI] [PubMed] [Google Scholar]
  9. Kimmich G. A., Randles J. A Na+-independent, phloretin-sensitive monosaccharide transport system in isolated intestinal epithelial cells. J Membr Biol. 1975 Aug 11;23(1):57–76. doi: 10.1007/BF01870244. [DOI] [PubMed] [Google Scholar]
  10. Kimmich G. A., Randles J. Energetics of sugar transport by isolated intestinal epithelial cells: effects of cytochalasin B. Am J Physiol. 1979 Jul;237(1):C56–C63. doi: 10.1152/ajpcell.1979.237.1.C56. [DOI] [PubMed] [Google Scholar]
  11. Kimmich G. A., Randles J. Phloretin-like action of bioflavonoids on sugar accumulation capability of isolated intestinal cells. Membr Biochem. 1978;1(3-4):221–237. doi: 10.3109/09687687809063849. [DOI] [PubMed] [Google Scholar]
  12. Kinne R., Berner W., Hoffman N., Murer H. Phosphate transport by isolated renal and intestinal plasma membranes. Adv Exp Med Biol. 1977;81:265–277. doi: 10.1007/978-1-4613-4217-5_26. [DOI] [PubMed] [Google Scholar]
  13. PLAYOUST M. R., ISSELBACHER K. J. STUDIES ON THE TRANSPORT AND METABOLISM OF CONJUGATED BILE SALTS BY INTESTINAL MUCOSA. J Clin Invest. 1964 Mar;43:467–476. doi: 10.1172/JCI104932. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Randles J., Kimmich G. A. Effects of phloretin and theophylline on 3-O-methylglucose transport by intestinal epithelial cells. Am J Physiol. 1978 Mar;234(3):C64–C72. doi: 10.1152/ajpcell.1978.234.3.C64. [DOI] [PubMed] [Google Scholar]
  15. Rose R. C., Schultz S. G. Studies on the electrical potential profile across rabbit ileum. Effects of sugars and amino acids on transmural and transmucosal electrical potential differences. J Gen Physiol. 1971 Jun;57(6):639–663. doi: 10.1085/jgp.57.6.639. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Environmental Health Perspectives are provided here courtesy of National Institute of Environmental Health Sciences

RESOURCES