SLC2A4 and diabetes mellitus: The main findings of the study are as follows: (1) In STZ-induced hyperglycemic and hypoinsulinemic rats, the phosphorylated Akt and membranous GLUT4 protein levels were markedly reduced in the heart, suggesting that insulin-stimulated Akt/GLUT4 signaling was impaired in STZ-induced insulin-deficient diabetes.