饮食限制对老龄大鼠寿命生存曲线的影响

Effect of dietary restriction on life-span of aged rats

目的观察不同饮食方式下老龄大鼠发生细胞自噬的差异,分析其自然寿命及生存曲线,探讨其抗衰老的生物学效应及机制。方法 45只24月龄雌性健康SD大鼠随机分成三组:对照组、隔日禁食组和两日禁食组。不同饮食方式干预第85天采集标本。透射电镜观察肝脏细胞自噬泡并对细胞的自噬活性进行定量分析;对各组自然死亡大鼠绘制生存曲线,进行生存分析;对细胞自噬活性和大鼠生存时间进行关联性分析。结果隔日禁食组和两日禁食组大鼠肝脏细胞自噬泡占胞质总面积的比值以及生存率与对照组比较增高,差异均有统计学意义(P<0.01),而此两组间差异无统计学意义。细胞自噬活性和大鼠生存时间之间呈线性正相关(rs=0.903,P<0.01)。结论细胞自噬呈高活性状态有利于大鼠寿命的延长;饮食限制导致寿命延长与细胞自噬相关。

Objective To explore the anti-aging effect and mechanism of dietary restriction by observing the difference of autophagy in rats with different dietary and analyzing the survival curve.Methods Forty-five female 24-month-old SD rats were randomly divided into 3 groups：control group,EOD group（every-other-day group,fed for a day and then fasting for a day）and two-day fasting group（continuously fed for 5 d and then fasting for 2 d）.The samples were taken at day 85 after the first fasting.Autophagosomes were observed under transmission electron microscopy.In addition,survival curves were drawn for survival analysis.Correlation between survival time and autophagic activity was investigated.Results Proportions of autophagosome to the total area of cytoplasm in EOD group and two-day fasting group were significantly higher than that in control group（P〈0.01）,but no significant difference was found between EOD group and two-day fasting group（P〉0.05）.Survival rates in EOD group and two-day fasting group were significantly higher than that in control group（P〈0.01）,but no statistical difference between EOD group and two-day fasting group（P〉0.05）.Survival time was positively correlated with autophagic activity（rs=0.903,P〈0.01）.Conclusion Autophagic activity at a high level may benefit the extension of life-span in rats.Dietary restriction-induced life expectancy extension may be associated with autophagy.