Semple Carson, Riveros Daniela, Nagy Janice A, Rutkove Seward B, Mortreux Marie
Harvard Medical School - Beth Israel Deaconess Medical Center, Department of Neurology, Boston, MA, United States.
Front Physiol. 2020 Apr 3;11:302. doi: 10.3389/fphys.2020.00302. eCollection 2020.
Many studies have investigated the physiological response to microgravity in both astronauts and animals. However, while space agencies have sought to deploy more women on their missions; animal models rarely include females studies or comparisons between males and females. Therefore, we exposed adult female rats to 2 weeks of partial weight-bearing at either 100% of their normal loading (PWB100) or 40% of their normal loading (PWB40), corresponding to Martian gravity-analog, and assess muscle function, force and histomorphometry. Females exposed to PWB showed an 11.62% decline in hindlimb grip force associated with an 11.84% decrease in soleus myofiber size after 14 days of exposure, while maintaining normal blood oxygenation and stress levels. This pilot study represents the first experiment designed to understand the muscular disuse associated with a partial reduction in mechanical loading in female rats, and the first step needed to develop successful mitigating strategies.
This research article describes the first use of quadrupedal partial weight-bearing in female rats. This study demonstrates the feasibility of partial gravity analogs in females and allows for future investigations about the impact of sex on muscle deconditioning due to reduced mechanical loading.
许多研究调查了宇航员和动物对微重力的生理反应。然而，尽管太空机构已寻求在其任务中部署更多女性；动物模型很少包括雌性研究或雌雄之间的比较。因此，我们将成年雌性大鼠暴露于相当于火星重力模拟的正常负荷的100%（PWB100）或40%（PWB40）的部分负重环境中2周，并评估肌肉功能、力量和组织形态学。暴露于部分负重环境中的雌性大鼠在暴露14天后，后肢握力下降了11.62%，比目鱼肌纤维大小减少了11.84%，同时保持正常的血液氧合和应激水平。这项初步研究是首个旨在了解雌性大鼠因机械负荷部分降低而导致的肌肉废用的实验，也是制定成功缓解策略所需的第一步。
这篇研究文章描述了首次在雌性大鼠中使用四足部分负重。这项研究证明了部分重力模拟在雌性中的可行性，并为未来关于性别对因机械负荷降低导致的肌肉失健的影响的研究提供了可能。
