Abstract
Context: Masculinization depends on the fetal testis. Exposure of the human fetus during pregnancy to paracetamol or/and to other mild-analgesics is associated with an increased risk of cryptorchidism. Objective:We aimed at determining whether mild analgesics disrupted the morphology and endocrine function of the human testis.Design:We used an in vitro system based on the culture of human fetal testes exposed or not to paracetamol, its metabolite AM404, aspirin, indomethacin, ketoconazole at 10(-4) M to 10(-7) M.Setting:The study was conducted at the University of Rennes I.Patients/Participants:Human fetal testes were from pregnant women following induced abortion, between 7 and 12 weeks of gestation (GW). Main Outcome Measures:Testosterone (radioimmunoassay: RIA), Anti-Müllerian Hormone (AMH; ELISA), insulin-like factor 3 (INSL3; RIA), prostaglandin D2 and E2 (PGD2 and PGE2, respectively; ELISA), were assayed in the media. Testicular cells were counted using histology and image analysis. The possible nuclear receptor-mediated activities of the analgesics were investigated using reporter cell lines expressing estrogen (ERs), androgen (AR) and peroxysome proliferator-activated γ ( PPARγ) receptors.Results:Indomethacin and aspirin stimulated testosterone production, particularly by the younger testes (8-9 GW vs 10-12 GW). Paracetamol, AM404 and ketoconazole decreased INSL3 levels. Aspirin stimulated, whereas ketoconazole inhibited AMH production. PGE2 levels were inhibited by paracetamol, and aspirin in the 7-12 GW testes, and by indomethacin but only in 7-9.86 GW old testes. The inhibitory trends seen for PGD2 were not statistically significant. Conclusions:Analgesics at concentrations relevant to human exposure cause endocrine disturbances in the fetal testis. We suggest that the fetal human testis displays slight critical age windows for sensitivity to direct exposure to aspirin, indomethacin and paracetamol. The analgesic-induced inhibition of INSL3 may be the mechanism by which analgesics increase the risk of cryptorchidism. Greater caution is required concerning consumption of analgesics during pregnancy.