Renal and intestinal hexose transport in familial glucose-galactose malabsorption

Possible Sodium and D-Glucose Cotransport in Isolated Jejunal Epithelium of Children

“…In all samples of jejunum, the ratio was greater than unity. These observations are in good agreement with the 4.5 accumulation ratio found by Elsas et al (14) for 10 mM D-glucose in jejunum of human adults.…”

“…There is no overlap between the values obtained in control and in Nafree solutions. These results are also in agreemeent with results on adult human jejunum (14) where ouabain produced a 85% inhibition and Na-free solution a 90% inhibition of D-glucose accumulation. These observations suggest that the overall D-glucose intracellular accumulation is Na-dependent.…”

“…This difficulty, however, cannot account for the different results observed in different experimental conditions. The second possibility for error could be the use of 14C counts to measure the intracellular glucose concentration; in fact, it has been found that the glucose specific activity in the tissue extract equal to that of the extracellular glucose; similar results were obtained previously on human jejunal biopsies (14). The absence of glucose metabolism in this situation is somewhat different from what has been found in animal intestine.…”

“…At first, the measurements depend on the determination of the intracellular volume that, in turn, depends on the determination of the extracellular volume. For this measurement, 3H inulin has been used for a long time on human (12,14) and on animal intestine (32,35). Its validity has been recently reassessed in rabbit ileum (24).…”

“…Accumulation experiments (12,14). The piece of jejunum that consisted of the epithelial layer was generally divided into two or three pieces of 3-10 mg each except if the original piece was too small.…”