Department of Gynecology and Obstetrics, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, PR China.
Aging Clin Exp Res. 2012 Apr;24(2):125-33. doi: 10.3275/7660. Epub 2011 Apr 14.
Caloric restriction (CR) extends mammals' lifespans and suppresses ovary development. Sirtuins are involved in these mechanisms. If, and to what extent CR affects ovarian lifespan and follicle development is largely unknown. We investigated the effects of moderate and severe caloric restriction compared with a high-fat dietary regimen on ovarian follicle reserves in rats.
Female Sprague-Dawley rats (n=48) randomly divided into four groups including normal control (NC), 25% caloric restriction (MCR), 45% CR (SCR) and high-fat diet (HF) were maintained on these regimens for 2 months.
Histological analysis showed that both the 25 and 45% CR rats had a significantly higher percentage of primordial follicles and a larger number of healthy follicles than the NC rats, whereas the HF rats did not differ significantly from the NC rats. Immunohistochemical analysis revealed that SIRT1 and SIRT6 proteins were present in the nucleus and cytoplasm of the oocytes. The 25% CR diet increased the expression of both SIRT1 and SIRT6 in the ovary, whereas the 45% CR and HF diets caused a decrease in SIRT1 expression. The level of SIRT6 protein did not change with the 45% CR diet, and it appeared slightly lower in the HF than in the NC groups.
Caloric restriction may inhibit the transition from primordial to developing follicles and extend the entire growth phase of a follicle to preserve the reserve of germ cells. SIRT1 and SIRT6 are both associated with these effects.
热量限制（CR）可延长哺乳动物的寿命并抑制卵巢发育。Sirtuins 参与了这些机制。CR 是否以及在何种程度上影响卵巢寿命和卵泡发育还知之甚少。我们研究了与高脂肪饮食方案相比，适度和重度热量限制对大鼠卵巢卵泡储备的影响。
将雌性 Sprague-Dawley 大鼠（n=48）随机分为四组，包括正常对照组（NC）、25%热量限制组（MCR）、45%热量限制组（SCR）和高脂肪饮食组（HF），这些组别的大鼠分别接受相应的饮食方案喂养 2 个月。
组织学分析显示，与 NC 组相比，25%和 45%的 CR 组大鼠的原始卵泡比例显著更高，健康卵泡数量更多，而 HF 组大鼠与 NC 组大鼠无显著差异。免疫组织化学分析显示，SIRT1 和 SIRT6 蛋白存在于卵母细胞的核和细胞质中。25%的 CR 饮食增加了卵巢中 SIRT1 和 SIRT6 的表达，而 45%的 CR 和 HF 饮食导致 SIRT1 表达降低。SIRT6 蛋白水平不受 45%的 CR 饮食影响，在 HF 组中似乎略低于 NC 组。
热量限制可能会抑制原始卵泡向发育卵泡的转变，并延长卵泡的整个生长阶段，从而保留生殖细胞的储备。SIRT1 和 SIRT6 都与这些作用有关。
