title: Effects of 3,3',4,4',5-pentachlorobiphenyl, a coplanar polychlorinated biphenyl congener, on cultured neonatal mouse testis.
abstract: 3,3',4,4',5-Pentachlorobiphenyl (PCB126), a congener with a planar configuration, has been established to have relatively strong toxicities similar to those of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) via aryl hydrocarbon receptors. We investigated the effects of this coplanar PCB on mammalian early spermatogenesis and steroidogenesis in a mouse neonatal testicular organ culture system. Testes collected from newborn mice were subjected to organ culture in medium containing 0, 10, 100 or 1000 nM PCB126. Histochemical analysis revealed that the BrdU-labeling indices of both spermatogenic cells and Sertoli cells were unchanged in all testis specimens exposed to the coplanar PCB. CYP1A1 and steroidogenic enzymes (P450scc, P450c17, 3beta-HSD and 17beta-HSD) mRNA levels were determined by semiquantitative RT-PCR. The CYP1A1 mRNA level in cultured testis was significantly increased by PCB126 in a dose-dependent manner. Although mRNA levels of 3beta-HSD and 17beta-HSD were unchanged, the P450scc mRNA level was significantly down-regulated by PCB126 in a dose-dependent manner. In contrast, the P450c17 mRNA level was significantly higher in 1000 nM PCB126-exposed testis than in control testis. These results suggest that the coplanar PCB does not alter the proliferative activity of spermatogenic cells and Sertoli cells in neonatal testis, but that it directly affects the expression of steroidogenic enzyme genes.
authors.affiliation: Molecular and Cellular Toxicology Section, National Institute for Environmental Studies, 16-2 Onogawa, 305-8506, Tsukuba, Japan.
authors.forename: N H
authors.initials: NH
authors.lastname: Fukuzawa
authors.forename: S
authors.initials: S
authors.lastname: Ohsako
authors.forename: R
authors.initials: R
authors.lastname: Nagano
authors.forename: M
authors.initials: M
authors.lastname: Sakaue
authors.forename: T
authors.initials: T
authors.lastname: Baba
authors.forename: Y
authors.initials: Y
authors.lastname: Aoki
authors.forename: C
authors.initials: C
authors.lastname: Tohyama
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002455:Cell Division; D019363:Cytochrome P-450 CYP1A1 / Q000032:analysis / Q000096:biosynthesis; D015536:Down-Regulation; D004965:Estrogen Antagonists / Q000633:toxicity*; D005786:Gene Expression Regulation / Q000187:drug effects; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009924:Organ Culture Techniques; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D012333:RNA, Messenger / Q000032:analysis; D013091:Spermatogenesis / Q000187:drug effects*; D013737:Testis / Q000187:drug effects* / Q000473:pathology*
chemical_list: D004965:Estrogen Antagonists; D012333:RNA, Messenger; D011078:Polychlorinated Biphenyls; D019363:Cytochrome P-450 CYP1A1; C023035:3,4,5,3',4'-pentachlorobiphenyl