Metabolic effect of sodium selenite: Insulin-like inhibition of glucagon-stimulated glycogenolysis in the isolated perfused rat liver

✍ Scribed by Michael Roden; Martin Prskavec; Clemens Fürnsinn; Ibrahim Elmadfa; Jürgen König; Barbara Schneider; Oswald Wagner; Werner Waldhäusl

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 694 KB
• Volume: 22
• Category: Article
• ISSN: 0270-9139
• DOI: 10.1002/hep.1840220127

✦ Synopsis

Selenium, an essential trace element, has been shown to decrease plasma glucose concentrations of diabetic rats. To study the short-term effects of selenium on hepatic carbohydrate metabolism, isolated perfused livers of fed Sprague-Dawley rats were continuously infused with sodium selenite for 90 minutes. This resulted in an immediate elevation of selenium in the effluent perfusate (3.3 t-0.1,16.1 t-0.4,30.3 t-1.6, and 118.9 ? 0.8 pmoVL at infusion of 10,50,100, and 500 pmoVL sodium selenite, respectively). Basal hepatic glucose production decreased in a dose-dependent manner within 60 minutes of low-dose sodium selenite infusion (10 0.60 t-0.20, 50: 0.21 2 0.40, and 100 p m o l h 0.21 t 0.09 pmol min-' * g-' liver; P < .05 vs. zero time), while it was transiently increased by 500 pmoVL sodium selenite (1.11 ? 0.18 pmol . min-'g-' liver; P < .05). Glucagon-stimulated glycogenolysis was suppressed by 50% (P < .05) at 1.8 nmoY L insulin and by 90% (P < .001) at 10 pmoVL sodium selenite. That selenium concentration did not affect glutathione peroxidase activities in liver and perfusate erythrocytes within 60 minutes. Toxic effects of highdose selenite (500 pmoVL), but not of low-dose selenite (10 pmoVL) infusion, were indicated by increased hepatic glucose (P < .05), lactate (P < .Ol), and lactate dehydrogenase (P < .001) release as well as histologically by degeneration and necrosis of periportal hepatocytes. In conclusion, low-dose selenite exerts a potent insulinlike effect on hepatic glycogenolysis in vitro by counter-Abbreviations: GSH-Px, glutathione peroxidase; K-R, Krebs-Ringer; BSA, bovine serum albumin; IP, intraperitoneally; LDH, lactate dehydrogenase; ASAT, aspartate aminotransferase; IU, international units; AUC, area under the glucose-time curve.

From the' Division of Endocrinology and Metabolism, Department of Internal Medicine 111; the