Effect of exercise training on in vivo insulin-stimulated glucose uptake in intra-abdominal adipose tissue in rats

Intra-abdominal obesity may be crucial in the pathogenesis of the insulin-r esistance syndrome, and training may alleviate this condition. We compared insulin-mediated glucose uptake in vivo in three intra-abdominal adipose ti ssues (ATs; retroperitoneal, parametrial, and mesenteric) and in subcutaneo us AT and also studied the effect of training. Rats were either swim traine d (15 wk, n = 9) or sedentary (n = 16). While the rats were under anesthesi a, a hyperinsulinemic (similar to 900 phl), euglycemic clamp was carried ou t and local glucose uptake was measured by both the 2-deoxy-D-[H-3] glucose and microdialysis techniques. Blood flow was measured by microspheres. Upo n insulin stimulation, blood flow generally decreased in AT. Flow was highe r in mesenteric tissue than in other ATs, whereas insulin-mediated glucose uptake did not differ between ATs. Training doubled the glucose infusion ra te during hyperinsulinemia, in part, reflecting an effect in muscle. During hyperinsulinemia, interstitial glucose concentrations were lower, glucose uptake per 100 g of tissue was higher in AT in trained compared with sedent ary rats, and training influenced glucose uptake identically in all ATs. In conclusion, differences between Am in insulin sensitivity with respect to glucose uptake do not explain that insulin resistance is associated with in tra-abdominal rather than subcutaneous obesity. Furthermore, training may b e beneficial by enhancing insulin sensitivity in intra-abdominal fat depots .