Obesity and Comorbidities Research Center (OCRC), Institute of Biology, Universidade Estadual de Campinas, Campinas, SP, Brazil.
Diabetes and Obesity Research Division, Biomedical Research Department, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA, 90048, USA.
Amino Acids. 2018 Apr;50(3-4):469-477. doi: 10.1007/s00726-017-2533-z. Epub 2017 Dec 27.
Low levels of estrogens are associated with obesity-related comorbidities. Mice with lower levels of estrogens are thereby more sensitive to the effects of a high-fat-diet (HFD) for the development of glucose intolerance and insulin resistance. Studies in vivo have demonstrated that taurine (TAU) supplementation prevents glucose and insulin resistance. Thus, we aimed to investigate the potential beneficial effects of TAU supplementation on glucose homeostasis of mice with low levels of estrogens fed with a HFD. 3-month-old female C57BL/6J mice underwent bilateral ovariectomy (OVX). After 1 week of recovery, mice were divided into 4 groups and either received: a standard chow diet (OVXC), chow diet plus drinking water enriched with 3% of TAU (OVXCT), HFD (OVXH), and HFD plus supplementation of TAU (OVXHT) for 14 weeks. Exposure to the HFD increased adiposity and plasma levels of glucose and insulin. Contrary to our prediction, the addition of TAU enhanced the deleterious effects of the HFD. Glucose and insulin tolerance tests (ipGTT and ipITT) indicated that mice maintained on the HFD + TAU had worse glucose intolerance and insulin resistance that was linked to lower insulin signaling in skeletal muscle and liver. Insulin secretion of isolated pancreatic islets of OVXH mice was higher than OVXC, and the addition of TAU associated with a HFD did not modulate insulin secretion, suggesting a failure of pancreatic β cells of OVXHT mice. These results suggest that despite the beneficial reports of TAU, it should be used cautiously in situations where the levels of estrogens are low.
雌激素水平低与肥胖相关的合并症有关。雌激素水平较低的小鼠因此更容易受到高脂肪饮食(HFD)的影响,从而导致葡萄糖不耐受和胰岛素抵抗。体内研究表明,牛磺酸(TAU)补充可预防葡萄糖和胰岛素抵抗。因此,我们旨在研究 TAU 补充对 HFD 喂养的雌激素水平低的小鼠葡萄糖稳态的潜在有益作用。3 个月大的雌性 C57BL/6J 小鼠接受双侧卵巢切除术(OVX)。恢复 1 周后,将小鼠分为 4 组,分别接受:标准饲料(OVXC)、添加 3%TAU 的饮用水(OVXCT)、HFD(OVXH)和 HFD 加 TAU 补充剂(OVXHT),持续 14 周。暴露于 HFD 会增加肥胖和血浆葡萄糖和胰岛素水平。与我们的预测相反,TAU 的添加增强了 HFD 的有害影响。葡萄糖和胰岛素耐量试验(ipGTT 和 ipITT)表明,继续食用 HFD+TAU 的小鼠的葡萄糖耐量和胰岛素抵抗更差,这与骨骼肌和肝脏中的胰岛素信号降低有关。OVXH 小鼠分离的胰岛的胰岛素分泌高于 OVXC,并且添加 TAU 与 HFD 相关联并没有调节胰岛素分泌,提示 OVXHT 小鼠的胰岛β细胞功能衰竭。这些结果表明,尽管有 TAU 的有益报告,但在雌激素水平较低的情况下应谨慎使用。