Ribeiro Rosane A, Bonfleur Maria L, Amaral Andressa G, Vanzela Emerielle C, Rocco Silvana A, Boschero Antonio C, Carneiro Everardo M
Departamento de Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil.
Diabetes Metab Res Rev. 2009 May;25(4):370-9. doi: 10.1002/dmrr.959.
Taurine (TAU), a naturally occurring sulfur-containing amino acid, is found at high concentrations in plasma and mammalian tissues and regulates osmolarity, ion channel activity, and glucose homeostasis. Several reports have shown that physiological plasma TAU levels seem to be important for adequate beta (beta)-cell function and insulin action, since low concentrations of TAU in the plasma have been reported in the pre-diabetic and diabetic states.
Glucose tolerance and insulin sensitivity were investigated in mice supplemented with 2% (w/v) TAU in their drinking water for 30 days, as well as the insulin secretion from isolated islets stimulated by glucose or L-leucine.
TAU-supplemented mice demonstrated improved glucose tolerance and higher insulin sensitivity, compared to controls (CTL). In addition, their islets secreted more insulin in response to high concentrations of glucose and L-leucine. L-[U-(14)C]leucine oxidation was higher in TAU than in CTL islets, whereas D-[U-(14)C]glucose oxidation, ATP levels, glucose transporter (GLUT) 2 and glucokinase (GCK) protein expressions were similar in both types of islets. The L-type beta(2) subunit voltage-sensitive Ca(2+) channel protein, as well as (45)Ca uptake, were significantly higher in TAU-supplemented than CTL islets. In addition, islets from TAU-supplemented mice secreted more glucagon than CTL islets at low glucose.
TAU supplementation improves glucose tolerance and insulin sensitivity in mice, as well as insulin secretion from isolated islets. The latter effect seems to be, at least in part, dependent on a better Ca(2+) handling by the islets.
牛磺酸（TAU）是一种天然存在的含硫氨基酸，在血浆和哺乳动物组织中含量很高，可调节渗透压、离子通道活性和葡萄糖稳态。多项报告表明，生理性血浆TAU水平似乎对足够的β细胞功能和胰岛素作用很重要，因为在糖尿病前期和糖尿病状态下，血浆中TAU浓度较低的情况已有报道。
对饮用水中添加2%（w/v）TAU 30天的小鼠进行葡萄糖耐量和胰岛素敏感性研究，以及葡萄糖或L-亮氨酸刺激下分离胰岛的胰岛素分泌研究。
与对照组（CTL）相比，补充TAU的小鼠表现出改善的葡萄糖耐量和更高的胰岛素敏感性。此外，它们的胰岛对高浓度葡萄糖和L-亮氨酸的反应分泌更多胰岛素。TAU胰岛中L-[U-(14)C]亮氨酸氧化高于CTL胰岛，而两种胰岛中D-[U-(14)C]葡萄糖氧化、ATP水平、葡萄糖转运蛋白（GLUT）2和葡萄糖激酶（GCK）蛋白表达相似。补充TAU的胰岛中L型β(2)亚基电压敏感性Ca(2+)通道蛋白以及(45)Ca摄取显著高于CTL胰岛。此外，在低葡萄糖水平下，补充TAU小鼠的胰岛比CTL胰岛分泌更多胰高血糖素。
补充TAU可改善小鼠的葡萄糖耐量和胰岛素敏感性，以及分离胰岛的胰岛素分泌。后一种作用似乎至少部分取决于胰岛更好的Ca(2+)处理能力。
