自然衰老SD大鼠肌少症模型生理特征的多维度评价研究

Multidimensional evaluation of physiological characteristics of sarcopenia model in naturally aging SD rats

中文关键词: 肌少症  SD大鼠  抓力  低场核磁共振  腹围身长比

英文关键词: sarcopenia  SD rat  grip strength  low-field nuclear magnetic resonance  waist-to-height ratio

中文摘要:

      目的 评估25月龄自然衰老SD大鼠的肌肉质量、功能参数及体成分变化,完善肌少症动物模型的标准化评价体系.方法 选取25月龄(老年组,n=40)和5月龄(青年组,n=40)雄性SD大鼠,测量体质量、身长、腹围、抓力、肱二头肌围度,计算腹围身长比(WHtR)、抓力体质量比(GSWtR)、肱二头肌围度体质量比(BCWtR).低场核磁小动物体成分分析仪获取脂肪质量、肌肉质量、瘦体质量百分比和脂肪水平百分比,计算脂肪质量指数(FMI)、肌肉质量指数(MMI)、全身肌肉脂肪比(MFR).苏木素-伊红(HE)染色和透射电镜观察肱二头肌肌肉组织细胞形态.结果 与青年组相比,老年组腹围(204.50 mm vs 262.00 mm)、WHtR(0.80 vs 0.86)、脂肪质量(34.76 g vs 93.84 g)和 FMI(0.56 vs 1.05)升高,瘦体质量百分比(35.93％vs 18.89％)、MMI(2.97 vs 1.87)、MFR(5.52 vs 1.77)、抓力(944.55 gf vs 394.59 gf)、GSWtR(1.69 vs0.45)及 BCWtR[(0.10±0.01)vs(0.06±0.01)]降低(P＜0.05).HE 染色显示,与青年组相比,老年组肱二头肌肌纤维横截面积减少[(0.42±0.02)mm2 vs(0.28±0.03)mm2],透射电镜可见肱二头肌肌纤维密度降低.结论 WHtR、FMI、MMI、MFR、GSWtR和BCWtR可作为非侵入式指标评估SD大鼠肌少症模型关键生理特征.

英文摘要:

      Objective To evaluate the changes in muscle mass,functional parameters and body composition in 25-month-old naturally aged SD rats,and improve the standardized evaluation system of sarcopenia animal models.Methods Male SD rats at 25 months old(elderly group,n=40)and 5 months old(youth group,n=40)were selected.Body weight,body length,abdominal circumference,grip strength,and biceps brachii circumference were measured.The waist-to-height ratio(WHtR),grip strength-to-body weight ratio(GSWtR),and biceps circumference-to-body weight ratio(BCWtR)were calcu-lated.The low-field nuclear magnetic resonance small animal body composition analyzer was used to obtain the fat mass,mus-cle mass,lean body mass percentage and the fat level percentage.The fat mass index(FMI),muscle mass index(MMI),and whole-body muscle fat ratio(MFR)were calculated.The morphology of biceps brachii muscle tissue cells was observed by he-matoxylin-eosin(HE)staining and transmission electron microscopy(TEM).Results Compared with the youth group,the abdominal circumference(204.50 mm vs 262.00 mm),WHtR(0.80 vs 0.86),fat mass(34.76 g vs 93.84 g),and FMI(0.56 vs 1.05)in the elderly group increased,while the lean body mass percentage(35.93％vs 18.89％),MMI(2.97 vs 1.87),MFR(5.52 vs 1.77),grip strength(944.55 gf vs 394.59 gf),GSWtR(1.69 vs 0.45)and BCWtR[(0.10±0.01)vs(0.06±0.01)]decreased(P＜0.05).HE staining showed that compared with the youth group,the cross-sectional area of biceps brachii muscle fibers in the elderly group decreased[(0.42±0.02)mm2 vs(0.28±0.03)mm2],and TEM analysis fur-ther indicated a decrease in the muscle fiber density of the biceps brachii.Conclusion WHtR,FMI,MMI,MFR,GSWtR and BCWtR can be used as non-invasive indicators to evaluate the key physiological characteristics of sarcopenia models in SD rats.