Effect of insulin induced hypoglycaemia on in vitro uptake of 3-O-methylglucose by rat jejunum.

Acute hypoglycaemia (less than 2.0 mmol/l) selectively increased in vitro 3-O-methylglucose uptake by rat jejunum. In contrast, uptake of 3H-phenylalanine or 59Fe (III) was unchanged in the hypoglycaemic animals. The hypoglycaemia was accompanied by decreased tissue adenosine nucleotide energy charge. The increased uptake was phlorrhidzin-inhibitable and therefore reflected increased Na+ dependent glucose carrier activity. Cycloheximide did not block the increased 3-O-methylglucose uptake, implying that the mechanism is not the result of increased de novo carrier protein synthesis.