为探讨海洋胶原肽长期喂养对SD大鼠生存时间的影响，选用4周龄SD大鼠160只，随机分为空白对照组和3个剂量的MCP干预组，每组40只，雌雄各半。对照组和3个剂量的MCP干预组的大鼠分别给予普通标准饲料和在对照组饲料的基础上分别添加2.25%、4.5%和9%的MCP干预组饲料至自然衰老死亡。实验过程中记录大鼠的体重、摄食量、食物利用率，每6月对大鼠血清的抗氧化相关指标超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-PX）活性及丙二醛（MDA）水平进行检测。生存分析结果表明，3个剂量的MCP干预组的中位生存时间，尤其是最后30%存活动物的生存时间均显著长于对照组；在干预18和24月时，4.5%和9%MCP干预组的血清SOD酶和GSH-PX的活性在雌雄大鼠均显著高于对照组，而MDA的水平则显著低于对照组。本研究表明，一定剂量的MCP长期干预可对大鼠生存时间有一定的延长作用，而MCP对SD大鼠衰老过程中机体抗氧化能力的提高作用可能是其中机制之一。
To investigate the effect of long-term administration of marine collagen peptides on the life-span of SD rats, 160 SD rats of four weeks old were divided into the control group and MCP-treated groups, with 40 rats in each group (male:female=1:1). Control rats were fed with standard basal diets and the rats in the experimental groups were fed with 2.25%, 4.5% and 9% MCP in the control diet until their natural death. The bodyweight, food consumption and food efficiency were recorded throughout the experiment. The activity of serum antioxidant enzymes GSH-PX and SOD and the level of MDA were examined every six months. The results show that the MCP does not signifiantly influence body weight, food consumption or food efficiency of rats of either sex throughout the life span. The survival analysis shows that the median lifespan, the lifespan of the last 30% survivals and the maximal life span of MCP treated groups were notably longer than those in the control group. MCP did significantly inhibit the age-related decrease in the activities of antioxidant enzymes and the age-related increase in the levels of lipid peroxidation product in both sexes. When treated with MCP for 18 months and 24 months, the activities of serum GSH-PX and SOD enzymes of the 4.5% and 9% MCP treated rats were significantly higher than those of the control rats, whereas the serum level of MDA in the 4.5% and 9% MCP treated groups were significantly lower as compared with the control group. Therefore, the long-term administration of MCP could significantly extend the lifespan of SD rats, which might be attributed to the anti-oxidative property of marine collagen peptides.
