CHANGE IN TELOMERASE ACTIVITY OF RAT ORGANS DURING GROWTH AND AGING

Telomerase activity is usually undetectable in adult human tissues, hu t is positive in embryonic tissues and in cancers. In rodents, however , several organs of normal adult animals express substantial amounts o f telomerase activity. In this study, we observed the changes in the t elomerase activity in rat organs during growth and aging and found tha t telomerase activity showed chronological patterns which were charact eristic to organs. In lung and brain, the high telomerase activity of embryonic stage decreased rapidly after birth. In lymphoid tissues, te lomerase activity increased after birth and reached to its maximum at 4 to 7 week. In liver, it stayed at nearly constant level throughout l ife. The telomerase activity in regenerating rat liver decreased tempo rally immediately after partial hepatectomy, then increased to a level that is higher than normal control. In contrast, it rapidly diminishe d in the occluded lobes after ligation of portal veils branch. (C) 199 8 Academic Press.