The Action of Paracrine Inhibitory Factors in the Absence of Spermatogenesis Impairs in vivo BetaB Inhibin Subunit Synthesis in Human Seminiferous Tubules

ANDREONE, L; PELLIZZARI, E; BERGADÁ, I; CIGORRAGA, S; VENARA, M.; CHEMES, H; CAMPO, S.

Buenos Aires

Congreso; XXVI Reunion Anual de la Sociedad Latinoamericana de Endocrinología Pediatrica; 2016

The inhibin production and its hormonal regulation in culturedseminiferous tubules (ST) from a puberal patient with DSDXYwere studied. The serum profile, the presence of inhibin subunitsin the testis by immunohistochemistry and the hormonalregulation of ST inhibin production in vitro were determined. Seruminhibin B (InhB) was not detectable; levels of inhibin a-subunit(Pro-aC), FSH and LH were very high in relation to age. Thehistopathological examination revealed the predominance of matureSertoli cells in the ST; the immunohistochemistry showed thepresence of inhibin a-subunit and the absence of bB-subunit. Underbasal conditions, the cultured ST produced detectable levels ofboth inhibin molecular forms, InhB and Pro-aC. The addition ofFSH to the cultures stimulated Pro-aC production (p!< 0.01). Incontrast, no changes were observed in both inhibins productionunder other experimental conditions studied. These results confirmedthat FSH is not able to sustain InhB production in a pubertaltestis in the absence of the stimulatory factors produced bygerm cells; these findings also suggest the existence of inhibitorymechanisms that may have impaired in vivo testicular InhB productionin this patient. TNF-a, among others locally produced factors,may be involved in this inhibitory mechanism. It cannot ruledout that these factors could exert their action under other physiologicaland/or pathological conditions.