Taurine improves insulin sensitivity in the Otsuka Long-Evans Tokushima Fatty rat, a model of spontaneous type 2 diabetes.
Taurine improves insulin sensitivity in the Otsuka Long-Evans Tokushima Fatty rat, a model of spontaneous type 2 diabetes.
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DOI：
10.1093/ajcn/71.1.54
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发表时间：
2000
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影响因子：
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通讯作者：
Yutaka Nakaya;A. Minami;N. Harada;S. Sakamoto;Y. Niwa;M. Ohnaka
中科院分区：
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作者：
Yutaka Nakaya;A. Minami;N. Harada;S. Sakamoto;Y. Niwa;M. Ohnaka
牛磺酸是一种有效的抗氧化剂，据报道可改善链脲霉素诱导的糖尿病，其中糖尿病的发展是由氧自由基对胰腺β细胞的攻击引起的。然而，牛磺酸也通过转化为胆汁酸增加胆固醇的排泄，并有望改善胰岛素抵抗。目的观察牛磺酸对胰岛素抵抗和2型糖尿病模型大鼠大冢长-伊文思德岛脂肪（OLETF）大鼠胰岛素敏感性的影响。设计：16周龄雄性OLETF大鼠分为牛磺酸组和非牛磺酸组。作为非糖尿病对照，使用Long-Evans-Tokushima-Otsuka大鼠。在23和25周龄时进行口服葡萄糖耐量试验和高胰岛素正葡萄糖钳夹试验。结果OLETF大鼠存在高血糖和胰岛素抵抗，腹部脂肪堆积明显。补充牛磺酸组的腹部脂肪堆积、高血糖和胰岛素抵抗显著低于未补充牛磺酸组。OLETF大鼠的血清和肝脏三酰甘油和胆固醇浓度显着高于对照大鼠，而补充牛磺酸组显着低于未补充牛磺酸组，可能是因为胆固醇分泌到胆汁酸中的增加。补充牛磺酸的大鼠也表现出更高的一氧化氮分泌，证明了亚硝酸盐的尿排泄增加。结论牛磺酸通过降低血清胆固醇和甘油三酯水平，有效改善OLETF大鼠的代谢，其机制可能是通过增加胆固醇向胆汁酸的分泌，减少胆固醇的生成，从而增加一氧化氮的生成。
BACKGROUND Taurine, a potent antioxidant, has been reported to improve streptozotocin-induced diabetes mellitus, in which the development of diabetes results from an attack by oxygen free radicals on pancreatic beta cells. However, taurine also increases the excretion of cholesterol via conversion to bile acid and would be expected to improve insulin resistance. OBJECTIVE The effects of taurine on insulin sensitivity were examined in a model rat of insulin resistance and type 2 diabetes-the Otsuka Long-Evans Tokushima Fatty (OLETF) rat. DESIGN Male OLETF rats were divided into 2 groups at the age of 16 wk: a taurine-supplemented group and an unsupplemented group. As a nondiabetic control, Long-Evans-Tokushima-Otsuka rats were used. An oral-glucose-tolerance test and hyperinsulinemic euglycemic clamp were performed at the ages of 23 and 25 wk. RESULTS The OLETF rats had hyperglycemia and insulin resistance and they had a greater accumulation of abdominal fat than did control rats. Abdominal fat accumulation, hyperglycemia, and insulin resistance were significantly lower in the taurine-supplemented group than in the unsupplemented group. Serum and liver concentrations of triacylglycerol and cholesterol were significantly higher in the OLETF rats than in the control rats and were significantly lower in the taurine-supplemented group than in the unsupplemented group, presumably because of the increased secretion of cholesterol into bile acid. Taurine-supplemented rats also showed higher nitric oxide secretion, evidenced by increased urinary excretion of nitrite. CONCLUSION Taurine effectively improves metabolism in OLETF rats by decreasing serum cholesterol and triacylglycerol, presumably via increased secretion of cholesterol into bile acid and decreased production of cholesterol because of increased nitric oxide production.