外源性多胺对老年大鼠抗衰老作用的实验研究

摘要

目的 观察外源性多胺对自然衰老大鼠的抗衰老作用,并探讨其可能机制.方法 18月龄的老龄Wistar大鼠,多胺(精脒、精胺)灌胃给药6周,复制给药组动物模型(多胺给药组,polyamines),相同月龄的老龄Wistar大鼠为老年对照组(old),3月龄的Wistar大鼠为青年对照组(young).生化方法检测各组大鼠心脏、肝脏组织SOD活力、MDA含量.酶联免疫吸附实验(ELISA)法测定大鼠心脏、肝脏组织中TNF-α、IL-1β含量.透射电子显微镜观察心肌超微结构变化.结果 与青年对照组比,老年对照组心脏、肝脏组织SOD活力明显下降,MDA含量明显增加,TNF-α和IL-1β水平均有显升高;与老年对照组比,多胺给药组心脏、肝脏组织SOD活力明显升高,MDA含量明显降低,TNF-α、IL-1β水平明显降低.电镜观察结果显示:老年对照组的心肌可见大量脂褐素颗粒沉积,并可见线粒体数目减少、体积增大、基质疏松、嵴呈现絮状变;多胺给药组心肌肌节结构清晰,线粒体基质致密、嵴排列整齐,偶见脂褐素颗粒.结论 外源性多胺在一定程度上能够延缓自然衰老大鼠的衰老过程,其作用机制可能与提高老龄大鼠心脏、肝脏组织的抗氧化能力和抑制炎症介质的生成有关.%Aim To observe the anti-aging effects and possible mechanism of exogenous polyamines in oldaged rats. Methods Polyamines ( spermidine and spermine ) were given through intragastric administration to 18 months old-aged wistar rats as polyamines administration group ( polyamines ), while wistar rats of the same months acted as old control group ( old ),wistar rats of 3 months as young control group ( young ). Biochemical tests were conducted of the levels of malondialdehyde ( MDA ) and the activity of superoxide dismutase ( SOD ) in these rats' heart and liver tissues. The levels of TNF-α and IL-1β were determined by Enzyme-linked immunosorbent assay. Myocardial ultrastructures were observed with transmission electron microscope. Results In comparison with the young group, in the old group, the activity of SOD of heart and liver tissues decreased significantly, the contents of MDA as well as TNF-α and IL-1β increased dramatically. Compared with the old group, in the polyamines group, the activity of SOD increased strikingly while the levels of MDA. TNF-α and IL-1β decreased remarkably. From the transmission electron microscope, myocardia in the old control group was found to have lots of lipofuscin particle deposition; mitochondria increased in size, the number decreased.and the mitochondrial cristae presented flocculent changes. In the polyamines group, myocardial sarcomere structures showed clarity; mitochondrial matrix showed more density and mitochondrial cristae arranged in neat rows. and lipofuscin granules were seen occasionally. Conclusion To some extent. exogenous polyamines can delay the natural aging process of rats .and the action mechanism may be associated with improving the antioxidant capacity of old rats ' heart and liver, and inhibiting the generation of pro-inflammatory mediators.