Use of phlorizin binding to demonstrate induction of intestinal glucose transporters
Tóm tắt
We used specific binding of phlorizin to the intact intestinal mucosa in order to measure glucose transport site density in intestines of mice fed a high-carbohydrate or no-carbohydrate diet. Nonspecific binding varied with intestinal position but showed only modest dependence on diet. Specific binding to glucose transporters was 1.9 times greater in jejunum of high-carbohydrate mice than of no-carbohydrate mice; this ratio was the same as the ratio for Vmax values of actived-glucose uptake between the two diet groups. The gradient in specific binding of phlorizin along the intestine paralleled the gradient in Vmax of glucose transport. These results directly demonstrate that the increase in intestinal glucose transport caused by a high-carbohydrate diet is due to induction of glucose transporter. They also indicate that the normal positional graident in glucose transport along the intestine arises from a gradient in transporters, induced by the normal gradient in luminal glucose concentration.
Tài liệu tham khảo
Amsler, K., Cook, J.S. 1985. Linear relationship of phlorizin-binding capacity and hexose uptake during differentiation in a clone of LLC-PK1 cells.J. Cell. Physiol. 122:254–258
Bode, C., Eisenhardt, J.M., Haberich, F.J., Bode, J.C. 1981. Influence of feeding fructose and glucose absorption in rat jejunum and ileum.Res. Exp. Med. 179:163–168
Csaky, T.Z., Fischer, E. 1981. Intestinal sugar transport in experimental diabetes.Diabetes 30:568–574
Diamond, J.M., Karasov, W.H. 1984. Effect of dietary carbohydrate on monosaccharide uptake by mouse small intestinein vitro.J. Physiol. (London) 349:419–440
Diedrich, D.F. 1968. Is phloretin the sugar transport inhibitor in intestine?Arch. Biohem. Biophys. 127:803–812
Dowling, R.H. 1973. The influence of luminal nutrition on intestinal adaptation after small bowel resection and by-pass.In: Intestinal Adaptation. pp. 35–45. Schattauer, Stuttgart
Dowling, R.H., Booth, C. 1967. Structural and functional changes following small intestinal resection in the rat.Clin. Sci. 32:139–149
Ferraris, R.P., Diamond, J.M. 1986. A method for measuring apical glucose transporter site density in intact intestinal mucosa by means of phlorizin binding.J. Membrane Biol. 94:65–75
Hahn, P., Koldovsky, O. 1966. Utilization of Nutrients During Postnatal Development. Pergamon, Oxford
Karasov, W.H., Buddington, R.K., Diamond, J.M. 1986. Adaptation of intestinal sugar and amino acid transport in vertebrate evolution.In: Transport Processes, Iono- and Osmoregulation. R. Gilles and M. Gilles-Baillien, editors. pp. 227–239. Springer-Verlag, Berlin
Karasov, W.H., Diamond, J.M. 1983. Adaptive regulation of sugar and amino acid transport by vertebrate intestine.Am. J. Physiol. 245:G443-G462
Karasov, W.H., Diamond, J.M. 1986. Adaptation of intestinal nutrient transport.In: Physiology of the Gastrointestinal Tract. L.R. Johnson, editor. Raven, New York (in press)
Karasov, W.H., Pond, R.S., III, Solberg, D.H., Diamond, J.M. 1983. Regulation of proline and glucose transport in mouse intestine by dietary substrate levels.Proc. Natl. Acad. Sci. USA 80:7674–7677
Karasov, W.H., Solberg, D.H., Diamond, J.M. 1985. What transport adaptation enable mammals to absorb sugars and amino acids faster than reptiles?Am. J. Physiol. 249:G271-G283
Naftalin, R.J., Kleinzeller, A. 1981. Sugar absorption and secretion by winter flounder intestine.Am. J. Physiol. 240:G392-G400
Nunn A.S., Jr., Ellert, M.S. 1967. Absorption and electrolyte changes of intestinal mucosa following substrate induction.Am. J. Physiol. 212:711–716
Reischenauer, A.M., Gray, G.M. 1985. Abrupt induction of a membrane digestive enzyme by its intraintestinal substrate.Science 227:70–72
Scharrer, E., Wolfram, S., Raab, W., Amann, B., Agne, N. 1981. Adaptive changes of amino acid and sugar transport across the brush border of rat jejunum.In: Mechanisms of Intestinal Adaptation. J.W.L. Robinson, R.H. Dowling, and E.O. Riecken, editors. pp. 123–137. MTP Press, Lancaster
Silk, D.B.A., Dawson, A.M. 1979. Intestinal absorption of carbohydrate and protein in man.In: Gastrointestinal Physiology III. Vol. 19, pp. 151–203. R.K. Crane, editor. University Park Press, Baltimore
Stirling, C.E. 1967. High-resolution radioautography of phlorizin-3H in rings of hamster intestine.J. Cell. Biol. 35:605–618
Urban, E., Haley, D.P. 1978. Glucose transport by rat small intestine after extensive bowel resection.Am. J. Physiol. 226:1304–1308
Wright, E.M., Peerce, B.E. 1985. Sodium-dependent conformational changes in the intestinal glucose carrier.Ann. N.Y. Acad. of Sci. 456:108–117