title: Effects of maneb on testosterone release in male rats.
abstract: Maneb (Manganese ethylene-bis-dithiocarbamate) is a widely used fungicide in agriculture. In order to investigate its effect on male reproductive function, rats were intraperitonealy injected with maneb (1 and 4 mg/kg) for 9 or 18 days. After 6 and 14 days of treatment, the animals received human chorionic gonadotropin (hCG) via a jugular catheter and blood samples were collected at several intervals subsequent to the challenge. They were thereafter decapitated after 9 or 18 days, and organs (i.e., liver, seminal vesicles, and kidneys) were weighed. Leydig cells prepared from rats after 18 days of treatment were incubated with or without different stimulators or precursors [hCG, A23187, 25-OH-cholesterol (25-OH-C), or androstenedione] for 1 hour, and the media were analyzed for testosterone or pregnenolone. Liver glutathione and thiobarbituric acid reactive substances (TBARS) as well as serum alanine aminotransferase (ALT) activity were also measured. Further, Leydig cells and testicular interstitial cells (TICs) prepared from normal rats were incubated with maneb (3-100 µM) for 1 or 2 hours, and testosterone release was assessed. The results showed that administration of maneb (4 mg/kg) for 9 and 18 days did not alter liver function, but resulted in a decrease of basal level of plasma testosterone (P < 0.01). In addition, basal testosterone and pregnenolone release by Leydig cells prepared from maneb 18-day treated animals were significantly reduced (P < 0.05). However, acute in vitro exposure of TIC or Leydig cells to maneb did not alter their testosterone release. These results suggested that maneb alters testosterone production, at least in part, through inhibition of CYP11A1 activitiy.
authors.affiliation: Laboratory of Pharmacology and Toxicology, Department of Biochemistry, Faculty of Science, University of Yaoundé, Cameroon. faustinpascal@yahoo.fr
authors.forename: Faustin P Tsagué
authors.initials: FP
authors.lastname: Manfo
authors.forename: Wen-Fang
authors.initials: WF
authors.lastname: Chao
authors.forename: Paul F
authors.initials: PF
authors.lastname: Moundipa
authors.forename: Michel
authors.initials: M
authors.lastname: Pugeat
authors.forename: Paulus S
authors.initials: PS
authors.lastname: Wang
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000037:antagonists & inhibitors / Q000378:metabolism; D006063:Chorionic Gonadotropin; D005659:Fungicides, Industrial / Q000633:toxicity*; D007274:Injections, Intraperitoneal; D007985:Leydig Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008344:Maneb / Q000633:toxicity*; D009929:Organ Size / Q000187:drug effects; D011284:Pregnenolone / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D013737:Testis / Q000187:drug effects* / Q000378:metabolism; D013739:Testosterone / Q000097:blood*
chemical_list: D006063:Chorionic Gonadotropin; D005659:Fungicides, Industrial; D008344:Maneb; D013739:Testosterone; D011284:Pregnenolone; D002786:Cholesterol Side-Chain Cleavage Enzyme