title: Differential effects of nonylphenol on testosterone secretion in rat Leydig cells.
abstract: Nonylphenol (NP), a final metabolite of nonylphenol polyethoxylate, has been reported to interfere with male reproduction. However, its mechanisms are not fully understood. In the present study, we examined the effects of NP on steroidogenesis of testosterone in rat Leydig cells. The testosterone concentrations in rat plasma were examined after intravenous injection of NP (100 microg/kg) at different time intervals. In addition, rat Leydig cells were challenged with different concentrations of NP (4.25-127.5 microM) to evaluate its influences on testosterone steroidogenesis. Administration of NP showed a decrease of hCG-induced plasma testosterone. Moreover, in vitro experiments revealed that NP (127.5 microM) alone stimulated testosterone release through increase of both protein levels and activities of the StAR and P450(SCC). In contrast, NP inhibited hCG-induced testosterone release in rat Leydig cells. The inhibitory effect was also observed after incubation of the Leydig cells in the presence of different precursors. These results suggested that NP had differential effects on testosterone synthesis.
authors.affiliation: Department of Physiology, School of Medicine, National Yang-Ming University, Shih-Pai, Taipei 11221, Taiwan, ROC.
authors.forename: Jen-Jung
authors.initials: JJ
authors.lastname: Wu
authors.forename: Kai-Lee
authors.initials: KL
authors.lastname: Wang
authors.forename: Shyi-Wu
authors.initials: SW
authors.lastname: Wang
authors.forename: Guey-Shyang
authors.initials: GS
authors.lastname: Hwang
authors.forename: I-Fang
authors.initials: IF
authors.lastname: Mao
authors.forename: Mei-Lien
authors.initials: ML
authors.lastname: Chen
authors.forename: Paulus S
authors.initials: PS
authors.lastname: Wang
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D007985:Leydig Cells / Q000187:drug effects*; D008297:Male; D010636:Phenols / Q000494:pharmacology*; D010750:Phosphoproteins / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D013739:Testosterone / Q000378:metabolism*; D000098682:Steroidogenic Acute Regulatory Protein
chemical_list: D010636:Phenols; D010750:Phosphoproteins; D000098682:Steroidogenic Acute Regulatory Protein; D013739:Testosterone; C025256:nonylphenol; D002786:Cholesterol Side-Chain Cleavage Enzyme