Effect of age on glucose oxidation by isolated rat islets

Islets were isolated from pancreases of 2-month and 12-month-old rats, and the oxidation of¹⁴C-glucose to¹⁴CO₂ determined at various medium D-glucose concentration. Islets from 12-month-old rats oxidized significantly less glucose than those from 2-month-old rats at glucose concentrations of 150, 300, and 450 mg/dl, and this was true when islets were selected by hand or by Ficoll density gradient separation. The effect of age on glucose oxidation was seen when islets were incubated with [U-¹⁴C], [1-¹⁴C], or [6-¹⁴C] glucose. The results raise the possibility that previously reported age-related defects in glucose-stimulated insulin secretion may be secondary to the effect of age on islet glucose catabolism.