Hexose recognition by insulin-secreting BRIN-BD11 cells

Clonal BRIN-BD11 cells were produced by electrofusion of NEDH rat islet B-cells with immortal RINm5F cells. Western blotting analysis revealed that unlike RINm5F, novel BRIN-BD11 cells expressed high levels of the glucose transport protein GLUT-2, coupled with a rapid and sustained uptake for D-glucose, significantly greater than RINm5F after only 5 min (p<0.05). Whereas BRIN-BD11 cells expressed a high glucokinase:hexokinase ration with 1.4-2.0 fold and 1.4-1.7 fold stepwise stimulation of insulin secretion with 4.2-16.7 nM D-glucose and D-mannose respectively. RINm5F had a lower glucokinase;hexokinase ratio (p<0.001) and were notably unresponsive to D-glucose and D-mannose. Unlike RINm5F cells, BRIN-BD11 were unresponsive to other hexoses, with RINm5F only responding to D-galactose (p<0.05). BRIN-BD11 cells should be useful for studies of nutrient-induced insulin secretion. (C) 1996 Academic Press, Inc.