TELOMERASE ACTIVITY IN THE TESTIS OF INFERTILE PATIENTS WITH SELECTEDCAUSES

In human testes, stem cells such as spermatogonia need to produce prog eny cells continually. Telomere length is maintained throughout sperma togenesis, i.e. from spermatogonia to spermatozoon, and telomerase is reported to be present in the testes. In this study, we measured the a ctivity of telomerase in the human testes of 16 cases of idiopathic az oospermia, 10 of obstructive azoospermia, and 17 of oligozoospermia in order to understand the role of telomerase in spermatogenesis. Telome rase activity in the testes with Sertoli cell-only and in testes with maturation arrest were 0.08 +/- 0.05 optical density (OD) (mean +/- SD ) and 1.96 +/- 0.98 OD, respectively (P < 0.05), Classifying those tes tes with maturation arrest into two groups, the telomerase activity of those with early maturation arrest (arrest at spermatocyte) and of th ose with late maturation arrest (arrest at round spermatid) was 1.82 /- 0.82 OD and 2.10 +/- 1.14 OD respectively. There was no significant difference between the two groups. The telomerase activity in the tes tes showing hypospermatogenesis in obstructive azoospermia and in thos e of oligozoospermia with hypospermatogenesis was 1.89 +/- 1.06 OD and 1.92 +/- 1.02 OD respectively. No difference in telomerase activity e xisted between the testes with maturation arrest and those with hyposp ermatogenesis in obstructive azoospermia or oligozoospermia. Sertoli c ell-only testes without germ cells showed no telomerase activity. The source of the telomerase activity was likely to be germ cells, The tel omerase activity in the testes (n = 63) was related to the histology o f the testes. The activity of telomerase showed no significant correla tion with the sperm concentration in each patient. Only serum oestradi ol level significantly correlated with telomerase activity (P < 0.05). The concentrations of follicle stimulating hormone, luteinizing hormo ne, or testosterone had no significant relationship with the telomeras e activity. Therefore similar levels of telomerase activity were detec ted in the testes of infertile men with azoospermia and oligozoospermi a and in testes showing maturation arrest.