Insulin secretion by pancreatic β-cells is stimulated by glucose, amino acids, and other
metabolic fuels. Glutamate dehydrogenase (GDH) has been shown to play a regulatory role
in this process. The importance of GDH was underscored by features of hyperinsulinemia/
hyperammonemia syndrome, where a dominant mutation causes the loss of inhibition by
GTP and ATP. Here we report the effects of green tea polyphenols on GDH and insulin
secretion. Of the four compounds tested, epigallocatechin gallate (EGCG) and epicatechin …