Figure 4. Metformin activates AMPK and reduces POMC, ACTH, cortisol, and glucose levels in vivo.

(a) Immunohistochemical staining (dark brown) of paraffin-embedded pituitary sections showed metformin (20 mg/kg) induced AMPK phosphorylation, and inhibited POMC and ACTH expression (left). The images are of a representative section (original magnification, ×400. Bar, 50 μm). The number of cells immunoreactive for p-AMPK, POMC, or ACTH was normalized to the total number of cells (right). Data represent the mean ± SE (n = 6). Relative quantification of the creatinine normalized urinary (b) cortisol and (c) glucose in rats before and after metformin treatment (once-daily for 3 consecutive days). Data are expressed as the mean ± SE (n = 6). *P < 0.05, the Wilcoxon signed ranks test used.