Influence of dioxin on the daily variation of insulin sensitivity in mice

Abstract

To evaluate an influence of dioxin on a daily variation of insulin sensitivity, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (100ng/kg) was given for 3 weeks in mice. Insulin tolerance test and oral glucose tolerance test were performed. TCDD decreased insulin sensitivity at an active period, but not at a rest period. TCDD elevated plasma TNF-α, and the value was significantly higher during an active period than during a rest period. These data suggest that TCDD blunts insulin sensitivity, mainly during an active period. Higher elevation in plasma TNF-α during an active period might be involved in this phenomenon.

Keywords: Chronotoxicology; Dioxin; Insulin sensitivity; TNF-α.