Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, Sao Paulo, Brazil.
Endocr Regul. 2021 Jan 29;55(1):1-4. doi: 10.2478/enr-2021-0001.
The onset of puberty in humans is followed by an increase in insulin resistance and this transient phenomenon decreases at the end of the puberty. However, the insulin resistance during puberty has not been described in mice. Thus, in the present study we performed a temporal characterization of the development of insulin resistance during puberty in male and female C57BL/6 mice. From the fourth week of life male (n=18) and female (n=32) C57BL/6 wild-type mice were weekly subjected to insulin tolerance tests until the seventh week of life. Blood glucose levels were determined using a glucose meter through samples collected from the tail tip. Vaginal opening was assessed daily in female mice. Preputial separation was determined in a subgroup of males. We observed a transient increase in the area under the curve of the insulin tolerance tests and in basal glycemia in female mice at the time of vaginal opening (between the fourth and fifth week of life) compared with previous and subsequent weeks of pubertal development. In contrast, male mice show no changes in insulin sensitivity during puberty. Our findings demonstrate that the insulin resistance at puberty can also be observed in female mice and this peak occurs at the time of vaginal opening. Our temporal characterization can be used as a reference for future studies that aim to study glucose homeostasis during puberty in rodents.
人类青春期的开始伴随着胰岛素抵抗的增加，而这种短暂的现象在青春期结束时会降低。然而，在小鼠中，青春期的胰岛素抵抗尚未被描述。因此，在本研究中，我们对雄性和雌性 C57BL/6 小鼠青春期胰岛素抵抗的发展进行了时间特征描述。从第四周开始，雄性（n=18）和雌性（n=32）C57BL/6 野生型小鼠每周接受胰岛素耐量试验，直到第七周。通过从尾尖采集的样本使用血糖仪测定血糖水平。每天评估雌性小鼠的阴道开口。在雄性小鼠的亚组中确定包皮分离。与青春期发育前和后的几周相比，我们观察到雌性小鼠在阴道开口时（第四至第五周），胰岛素耐量试验的曲线下面积和基础血糖值短暂增加。相比之下，雄性小鼠在青春期期间胰岛素敏感性没有变化。我们的研究结果表明，青春期的胰岛素抵抗也可以在雌性小鼠中观察到，而这一峰值出现在阴道开口时。我们的时间特征描述可作为未来研究啮齿动物青春期期间葡萄糖稳态的参考。
