The decrease of the expression of the Gαi2 and Gαi3 subunits and Gi-mediated AC signaling in the case of hyperglycemia induced by short-term STZ DM or high concentration of glucose (above 20 mM) may be attributed to the increase of O2− and ONOO− levels, since the treatment with antioxidants reversed the hyperglycemia-induced abnormalities in AC system to control [128]. Here, GNAI1 is linked to diabetes mellitus.