1998 年 25 巻 1 号 p. 25-30
Folate absorption was studied in rats with streptozotocin-induced diabetes. Absorption, as determined by the rise in serum folate levels after ingestion of either synthetic simple or dietary polyglutamylfolates, was observed to be 1.6-1.8-fold higher in diabetic rats than in normal ones. Folate transport in everted intestinal segments was also 60% higher in the diabetic animals. The enzyme folyl conjugase, which breaks down dietary polyglutamylfolates to simple absorbable forms, was induced 2-fold in pancreas 30min following folate ingestion in both control and diabetic animals. Luminal folyl conjugase, which showed very little activity at the onset, was elevated 7-9-fold after dietary folate ingestion in the control as well as in the diabetic group. These results indicate that the induction and release into the lumen of folyl conjugase is not adversely affected in diabetes and that the enhanced folate absorption and transport observed in diabetes might be physiological adaptation due to increased requirements.
