[Thymic factors influence on melatonin-producing pineal function in mice of different age: the possible mechanisms].

The aging peculiarities of thymic factors influence on pineal gland function in CBA mice were investigated. Significant increase of melatonin serum level in 3 h and decrease in 24 h after one injection of thymic preparation "thymalin" in adult mice was shown. The activating influence of thymalin was depended on season and linked with increase of thymic serum factor (FTS, thymulin) level and decrease of corticosterone blood level. Thymic stroma supernatant of adult mice, which had high level of FTS, intensified in vitro melatonin-producing pineal function. The activating influence of thymic factors in vivo and in vitro on pineal function in old mice was not revealed. FTS content increased and cortocosterone level did not change in old mice after injection of thymalin. The mechanisms of thymic factors influence on melatonin level in adult organism and their peculiarities in aging were discussed.