Expression of Hsp70-2 in rhesus monkey testis during germ cell apoptosis induced by testosterone undecanoate.

Hsp70–2 functions as a molecular chaperone that assists other proteins in their folding, transport and assembly into complexes, and is postulated to be linked to the mechanisms that inhibit apoptosis. Here we have determined the association between Hsp70–2 gene and germ cell apoptosis induced by a high dose of testosterone undecanoate (TU). In this study, in situ analysis of cell DNA fragmentation and expression of Hsp70–2 in TU-treated monkey testes were compared with the normal testes. The TUNEL analysis data showed that a large number of germ cell apoptotosis occurred in the testes on Day 30 after TU injection. Therefore, we speculate that spermatogenesis failure in TU-treated monkey testis may be a result of the germ cell apoptosis induced by a high dose of TU. As compared with that of normal testes, however, the level of Hsp70–2 mRNA was only slightly decreased while that of Hsp70–2 protein was almost unchanged in the testes from Day 7 to day 30 at the early stage of the germ cell apoptosis after TU treatment, but the levels of both Hsp70–2 mRNA and protein dropped dramatically on Day 60 when a large number of germ cells had undergone apoptosis and were depleted. Therefore, it is suggested that the Hsp70–2 may be not a molecule to prevent germ cell apoptosis induced by injection of TU in the testes at the early stage.