Androgen Receptor (AR) in the Human Prepubertal Testis: High Expression in Interstitial and Peritubular Cells and Very Low Expression in Sertoli and Germ Cells

ESPERANZA B. BERENSZTEIN; JORGE RODRIGUEZ; CANDELA R. GONZALEZ; NORA I. SARACO; MARCO A. RIVAROLA; ALICIA BELGOROSKY

Lyon, Francia

Congreso; ESPE/LWPES 7th Joint Meeting Pediatric Endocrinology; 2005

ESPE/LWPES

Androgen receptor (AR) in the human prepubertal testis: high  expresión in interstitial and peritubular cells and very low expresión in Sertoli and germ cells. Berensztein E, J Rodríguez, C Gonzalez, N Saraco, M.A Rivarola, A Belgorosky. Hospital de Pediatría Garrahan, Endocrine Service, Buenos Aires, Argentina We have describes a strong immunoexpression of aromatase in interstitial cells (IC) and in germ cells (GC), gonocytes and spermatogonia, in the neonatal and post natal human testicular activation periods, as well as during early prepuberty for GC. Strong expression of ERb in neonatal IC and in neonatal and prepubertal SC and GC was also observed. However, no data on AR immunoexpression in human prepubertal testis is available. In this study, 1) AR immunoexpression (cell localization and quantification of positive cells) in human prepubertal testicular tissue (n=20) was analized in different age groups. Human testicular tissue was collected at necropsy. As previously reported (Berensztein et al. J Clin Endocrinol Metab 87:5113, 2002), three age groups were defined: Gr1, neonatal (1- to 21-day-old newborns, n=7), Gr2, postnatal testicular activation (1- to 7-month-old infants, n=7) and Gr3, early prepubertal (12-to 36 month-old children, n=6) group. In IC, as well as in peritubular cells (PeC), a strong signal of AR immunoexpression (36±14.7, 34.8±19.8 and 20.5±9.23 % stained cells in IC, 63.5±14.7, 47.1±21.4 and 23.3±14.1 %  in PeC) was found in Gr1, Gr2 and Gr3, respectively. In PeC, % of Gr1 was significantly higher than that of Gr3, p=0.004. In the 3 Grs, SC immunoexpressionof AR was weak or absent (less than 5%), in contrast to one adult SC control, 75.8 %. Immunoexpression was completely absent in GC of the 3 Grs. We conclude that in human prepubertal testis, IC and PeC might be targets for androgen action, while SC might be targets for estrogens rather than androgens. In IC and PeC androgens might modulate its own AR. In the absence of AR, estradiol action might predominate in the seminiferous cords, maintaining a normal pool of precursor GC. The absence of AR in immature SC prevents androgen action, mainly the stimulation of spermatogenesis during prepuberty.