title: Inhibitory mechanisms of lead on steroidogenesis in MA-10 mouse Leydig tumor cells.
abstract: Lead can directly influence Leydig cell steroidogenesis, which results in reduction of testosterone and causes low sperm counts in human beings and animals. This study investigated the effect of 6 h incubation time of lead on steroidogenesis in MA-10 mouse Leydig tumor cells. Lead acetate, ranging from 10(-8) to 10(-5) M, caused profounder inhibitory effects on human chorionic gonadotropin (hCG)- and dibutyryl cAMP (dbcAMP)-stimulated progesterone production for 6 h in MA-10 mouse Leydig tumor cells. Lead acetate significantly inhibited hCG- and dbcAMP-stimulated progesterone production from 20 to 35% in MA-10 cells at 6 h. Lead suppressed the expression of steroidogenesis acute regulatory (StAR) protein from 30 to 55%. Moreover, the activities P450 side-chain cleavage (P450scc) enzyme and 3beta-hydroxysteroid dehydrogenase (3beta-HSD) were reduced by lead from 15 to 25%. Thus, after 6 h exposure to lead caused profounder inhibitory effects on StAR protein expression and steroidogenic enzymes and then progesterone production compared to 2- or 3-h lead treatments in MA-10 mouse Leydig tumor cells.
authors.affiliation: Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: M Y
authors.initials: MY
authors.lastname: Liu
authors.forename: S F
authors.initials: SF
authors.lastname: Leu
authors.forename: H Y
authors.initials: HY
authors.lastname: Yang
authors.forename: B M
authors.initials: BM
authors.lastname: Huang
mesh_terms: D000818:Animals; D003994:Bucladesine; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007854:Lead / Q000633:toxicity*; D007985:Leydig Cells / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051379:Mice; D009942:Organometallic Compounds / Q000633:toxicity*; D010750:Phosphoproteins / Q000096:biosynthesis; D011374:Progesterone / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured; D000098682:Steroidogenic Acute Regulatory Protein
chemical_list: D006063:Chorionic Gonadotropin; D009942:Organometallic Compounds; D010750:Phosphoproteins; D000098682:Steroidogenic Acute Regulatory Protein; D007854:Lead; D011374:Progesterone; D003994:Bucladesine; C008261:lead acetate