D-GLUCOSE METABOLISM IN BRIN-BD11 ISLET CELLS

A novel insulin-secreting cell line, BRIN-BD11, was recently establish ed following electrofusion of RINm5F cells with NEDH rat pancreatic is let cells. In the present study, D-glucose metabolism was compared in BRIN-BD11 and RINm5F cells. The concentration dependency of D-[5-H-3]g lucose utilization displayed a comparable pattern in the two cell line s, but the absolute values were lower in BRIN-BD11 than RINm5F cells. Except in the case of D-[1-C-14]glucose, the ratio between C-14 labele d D-glucose oxidation and D-[5-H-3]glucose utilization was higher, how ever, in BRIN-BD11 than RINm5F cells. Moreover, BRIN-BD11 cells were l ess affected than RINm5F cells by a rise in D-glucose concentration, i n terms of the inhibitory action of the hexose upon oxidative variable s, such as oxidative glycolysis, pyruvate decarboxylation, and oxidati on of glucose-derived acetyl residues in the Krebs cycle. The total en ergy yield from D-glucose catabolism appeared similar, however, in BRI N-BD11 and RINm5F cells. These findings extend the knowledge that BRIN -BD11 cells display an improved metabolic and secretory behavior, when considering the difference otherwise found between normal and tumoral islet cells. (C) 1996 Academic Press, Inc.