Acute and chronic leptin administration increase basal and fructose-stimulated GLUT2 and GLUT5 mRNA.
A, for acute studies, 16-hour deprived fasted mice receiving oral administration of saline (CTRL), 3 ng/g murine leptin, fructose (2 g/kg) or fructose in combination with leptin. They were sacrified 4 hours later, and total RNA was extracted from the jejunum mucosa for qRT-PCR analysis in duplicate using specific oligonucleotides for GLUT2 and GLUT5 genes. Results are means±SEM for 8 mice in each group. B, for chronic studies, mice fed a standard diet (SD) or a high-calorie diet (HFD), received saline (CTRL) or 3 ng/g leptin, administered daily by gavage for 7 days. Mice were killed on day 8 and total RNA was extracted from jejunum mucosa for qRT-PCR analysis. Results are means±SEM for 8 mice in each study and each group. * P<0.05; ** P<0.01 and *** P<0.001 vs CTRL. B insert, representative immunoblots of GLUT2 and GLUT5 proteins from jejunum extracts of mice fed a SD and a high-calorie diet (HFD) showing increased amount GLUT2 and GLUT5 proteins when mice were fed a HFD in comparison to those fed a SD.