Study On The Mechanism Of Serum Components Of Young Rats Delaying Senescence Of The Old Rats(Rattus Norvegicus)

Background: The pursuit of longevity has been the dream of mankind since the ancient times. The studies of senescence has been concerned by the scientific community for many years. Nowadays studies of young blood containing the potential anti-aging ingredients have become a focus due to a report that young mice blood can revese age-related cognitive impairments in mice. However, the detailed mechanism is unknown. In order to elucidate the mechanism underlying the phenotype that young blood delaying senescence, the phenomenon is investigated on the aspects of behavior, tissue and organ structure, gene expression profile, and biochemistry using rat( Rattus norvegicus) as experimental model.Method: The young serum was made by ourself from young rats( 2 month-age) at first, then it was injected into the adult rats(6 month and 29 month age, respectively) after it was specially treated by ourself. To explore the effect of young serum on alleviating the senescent phenotype of the old rats and to elucidate the mechanism underlying the phenotype, the effect of young serum on the behavior, the tissue and organ structure, gene expression profile, and biochemistry was investigated by the methods of MWM behavioral analysis, checking frozen sections through microscope, microarray, SDS-PAGE, respectively, using rat( Rattus norvegicus) as experimental model.Results: 1) The results based on MWM behavioral analysis indicate that the number of MWM table-passing by 6-month-old rats was significantly increased, and swimming velocity of 6-month-old and 29-month-old rats was significantly increased too after the test rats were injected by the young specially-treated serum. 2) The number of myofibrils of skeleton muscle of 34-month-old rats was significantly increased after the rats were injected by young serum through the checking of frozen section of skeleton on the field of microscope. 3) The expression profiles of genes were much changed after the old rats were injected the young serum. Among the changed genes, 812~2066 genes were up-regulated( 4%~9% in whole genome), and 1064~1402 genes were down-regulated( 5%~6% in whole genome), respectively. 4) muscle showed that young serum had significant effect on reducing the senescent phenotype of the aged rats. The results of gene expression profiling showed that gene expression occurred in some changes in the aged rats after young serum injection through bioinformatics analysis. Result of SDS-PAGE analysis displayed that there is few macromolecular protein in white serum. The potential factor in the young serum may not be macromolecular proteins.Conclusion: 1) Young rat serum significantly increased memory capacity and athletic ability of 6-month-age rats and significantly improved athletic ability of 29-month-age rats; 2) Young rat serum significantly improved the health of the skeletal muscle of 34-month-age rats; 3) Young rat serum significantly alter skeletal muscle genome-wide transcriptional pattern of old rats; 4) Young rat serum specially treated can delay the senescence of old rats better. In summary, young rat serum have a significant effect on delaying the senescence of old rats, but the mechanism is still unknown and needs further study.