Abstract
Summary
The transport of nonmetaboliz-able sugar, 3-methyl glucose (3MG), was studied in the isolated intestinal epithelial cells from rat small intestine. Epithelial cells when incubated in Krebs-Ringer bicarbonate (KRB) medium for 20 min (37°) accumulated 3MG to approximately 4 times its concentration in the medium. Active transport of 3MG into epithelial cells was abolished by: (a) replacement of Na+ in the KRB with K+ or choline, (b) addition of 0.1 mM dinitrophenol (DNP) or iodoacetamide (IA), or (c) anaerobic conditions. The passive uptake of 3MG into epithelial cells, however, varied under these conditions. The net uptake values as compared to control, approximately, were: 65% with DNP, 53% with IA or anoxia, and 40% in the absence of Na+. The greater decrease in 3MG uptake in the Na+ free medium might indicate a facilitation by Na+ of the passive 3MG transport process.
The technical assistance of Ms. Ann Mitchell is gratefully acknowledged.
This work was supported by grants from U. S. Public Health Service Grant No. HE 12278-04, U. S. Army Contract No. DA DA 17-69-C-9165, and General Research Support Grant No. SOI RR05491 from NIH.
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