Iwasa Takeshi, Matsuzaki Toshiya, Yiliyasi Mayila, Yano Kiyohito, Irahara Minoru
Department of Obstetrics and Gynecology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-Cho, Tokushima 770-8503, Japan.
Department of Obstetrics and Gynecology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-Cho, Tokushima 770-8503, Japan.
Steroids. 2017 Nov;127:18-23. doi: 10.1016/j.steroids.2017.08.014. Epub 2017 Sep 8.
Previously, we showed that chronic testosterone administration increased body weight (BW) and food intake (FI), but did not alter fat weight, in young female rats. To examine our hypothesis that the effects of androgens on BW, FI and body composition might be age-dependent, the effects of chronic testosterone administration were evaluated in rats of different ages; i.e., young and middle-aged rats. Although chronic testosterone administration increased BW gain, FI, and feed efficiency in both young and middle-aged rats, it increased visceral fat weight in middle-aged rats, but not in young rats. Therefore, it is possible that testosterone promotes the conversion of energy to adipose tissue and exacerbates fat accumulation in older individuals. In addition, although the administration of testosterone increased the serum leptin level, it did not alter hypothalamic neuropeptide Y mRNA expression in middle-aged rats. On the contrary, the administration of testosterone did not affect the serum leptin levels of young rats. Thus, testosterone might induce hypothalamic leptin resistance, which could lead to fat accumulation in older individuals. Testosterone might disrupt the mechanisms that protect against adiposity and hyperphagia and represent a risk factor for excessive body weight and obesity, especially in older females.
此前，我们发现长期给予睾酮可增加年轻雌性大鼠的体重（BW）和食物摄入量（FI），但不会改变脂肪重量。为了检验我们的假设，即雄激素对体重、食物摄入量和身体组成的影响可能与年龄有关，我们评估了长期给予睾酮对不同年龄大鼠（即年轻大鼠和中年大鼠）的影响。虽然长期给予睾酮增加了年轻大鼠和中年大鼠的体重增加、食物摄入量和饲料效率，但它增加了中年大鼠的内脏脂肪重量，而年轻大鼠没有。因此，睾酮有可能促进能量向脂肪组织的转化，并加剧老年个体的脂肪堆积。此外，虽然给予睾酮可提高中年大鼠的血清瘦素水平，但它并未改变中年大鼠下丘脑神经肽Y mRNA的表达。相反，给予睾酮对年轻大鼠的血清瘦素水平没有影响。因此，睾酮可能会诱导下丘脑瘦素抵抗，这可能导致老年个体脂肪堆积。睾酮可能会破坏预防肥胖和食欲亢进的机制，并成为体重超标和肥胖的一个风险因素，尤其是在老年女性中。
