The telomerase activities in several organs and strains of rats with ageing

Telomerase activity is known to be implicated both in cell immortalization and carcinogenesis. Telomerase activity has not been detected in most human somatic tissues. However, we previously confirmed that the activity is pre sent both in methylazoxymethanol acetate-induced rat colonic adenocarcinoma and non-treated colonic mucosa, presumably indicating the tissue-specific activity of the enzyme in rats. To determine the standard activity of rat t elomerase in various organs in relation to differences in sex, age and stra in, we examined the activity by using the telomeric repeat amplification pr otocol (TRAP) assay. The testis, liver, and colon mucosa showed the activit y. The brain had very low or negative activity in 5-week-old male rats of t he F344, SD, Wistar, Donryu or ACI strains. Age (5-week-old and 9-month-old ) or sex difference for the activity was not apparent in rats of these stra ins. In general, telomerase activity in the fetal brain, liver and kidney w as stronger than in the adult organ. The telomerase activity of each organ was different from that of human. This difference may indicate that the rat has a specific mechanism for maintaining the telomeric repeats of the chro mosome even in somatic tissues. The basic information resulting from this s tudy may be useful for the study of the role of telomerase in tumorigenesis in animal experiment models.