Interestingly, sub-chronic Pb exposure (0.2% Pb, drinking water, 32 days) was able to disrupt the insulin secretory function of Islets of Langerhans through activating GSK-3 and ER stress, and increased activity of gluconeogenic enzymes, PEPCK, and G6P in the liver, demonstrated by glucose intolerance in male adult Wistar rats [258]. This evidence concerns the gene INS and Glucose intolerance.