Thiazolidinediones Exert Difterent Effects on Insulin Resistance between Dexamethasone-Treated Rats and Wistar Fatty Rats.
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- KIMURA MAMORU
- The Third Department of Internal Medicine, Yamagata University School of Medicine
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- DAIMON MAKOTO
- The Third Department of Internal Medicine, Yamagata University School of Medicine
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- TOMINAGA MAKOTO
- The Third Department of Internal Medicine, Yamagata University School of Medicine
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- MANAKA HIDEO
- The Third Department of Internal Medicine, Yamagata University School of Medicine
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- SASAKI HIDEO
- The Third Department of Internal Medicine, Yamagata University School of Medicine
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- KATO TAKEO
- The Third Department of Internal Medicine, Yamagata University School of Medicine
抄録
We determined the in vivo effects of thiazolidinediones on insulin resistance induced by dexamethasone (Dx), as well as that observed in Wistar fatty (WF) rats, using glucose clamp technique to measure glucose uptake (Gu) and percent suppression of hepatic glucose output (HGOsup) to evaluate insulin resistance. Male Wistar rats were treated with Dx (0.5mg/kg/day) for 7 days. Pioglitazone (P) or troglitazone (T) was coadministered orally for the same period at 10 and 200mg/kg/day, respectively. Two, 5 and 20mU/kg/min. of insulin infusion rates (IIR) were used. The Gu levels at clamp steady-state at IIR20 in rats treated with Dx (16.4±4.7mg/kg/min.) were significantly lower than those in control rats (36.3±2.4). The Gu levels at the same IIR in rats coadminstered with P (19.6±3.2) and T (21.3±6.3) were slightly but significantly higher than that in rat treated with Dx. HGOsup at IIR5 in control rats (97.5±6.2%) was decreased by Dx treatment (52.1±31.3). This decrease was slightly but significantly ameliorated by addition of T (78.3±12.2). The Gu levels at IIR20 in WF rats (6.6±0.9) were decreased significantly from that in lean littermates of WF (WL) rats (25.8±2.1). This attenuation of Gu increase was completely ameliorated with administration of P (20.9±2.8) or T (22.2±3.9). The HGOsup at IIR20 in WF rats (17.4±11.2) was significantly decreased from that in WL rats. Administration of P or T ameliorated this decrease completely. These results indicate that Dx induces insulin resistance by mechanisms different from those in WF rat, hence thiazolidinedione administration can be only partially useful to treat insulin resistance induced by Dx.
収録刊行物
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- Endocrine Journal
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Endocrine Journal 47 (1), 21-28, 2000
一般社団法人 日本内分泌学会
