title: In vitro effects of estradiol-17β, monobutyl phthalate and mono-(2-ethylhexyl) phthalate on the secretion of testosterone and insulin-like peptide 3 by interstitial cells of scrotal and retained testes in dogs.
abstract: The objective was to determine the effects of estradiol-17β, monobutyl phthalate (MBP) and mono-(2-ethylhexyl) phthalate (MEHP) on testosterone and insulin-like peptide 3 (INSL3) secretions in cultured testicular interstitial cells isolated (enzymatic dispersion) from scrotal and retained testes of small-breed dogs. Suspension cultures were treated with estradiol-17β (0, 10, and 100 ng/mL), MBP (0, 0.8, and 8 mmol/L) or MEHP (0, 0.2, and 0.8 mmol/L) for 18 h, in the presence or absence of 0.1 IU/mL hCG. Testosterone (both basal and hCG-induced) and INSL3 (basal) concentrations were measured in spent medium. Effects of estradiol-17β, MBP, and MEHP on testosterone and INSL3 secretions were not affected (P > 0.15) by cell source (scrotal versus retained testis); therefore, data were combined and analyzed, and outcomes reported as percentage relative to the control. In testicular interstitial cells, basal testosterone secretion was increased (P < 0.01) by 100 ng/mL estradiol-17β (130.2 ± 10.6% of control). Among phthalates, 0.2 and 0.8 mmol/L MEHP stimulated (P < 0.01) basal testosterone secretion (135.5 ± 8.3% and 154.6 ± 12.9%, respectively). However, hCG-induced testosterone secretion was inhibited (P < 0.01) by 8 mmol/L MBP (67.7 ± 6.0%), and tended to be inhibited (P = 0.056) by 0.8 mmol/L MEHP (84.5 ± 5.6%). Basal INSL3 secretion was inhibited (P < 0.01) by 8 mmol/L MBP (73.6 ± 6.8%) and 0.8 mmol/L MEHP (76.9 ± 11.3%). In conclusion, we inferred that estradiol-17β and certain phthalate monoesters had direct effects on secretions of testosterone and INSL3 in canine testicular interstitial cells, with no significant difference between scrotal and retained testes.
authors.affiliation: Department of Advanced Pathobiology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan.
authors.forename: I N
authors.initials: IN
authors.lastname: Pathirana
authors.forename: N
authors.initials: N
authors.lastname: Kawate
authors.forename: M
authors.initials: M
authors.lastname: Tsuji
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.forename: S
authors.initials: S
authors.lastname: Hatoya
authors.forename: T
authors.initials: T
authors.lastname: Inaba
authors.forename: H
authors.initials: H
authors.lastname: Tamada
mesh_terms: D000818:Animals; D003456:Cryptorchidism / Q000378:metabolism / Q000662:veterinary; D004051:Diethylhexyl Phthalate / Q000031:analogs & derivatives* / Q000494:pharmacology; D004283:Dog Diseases / Q000378:metabolism; D004285:Dogs; D004958:Estradiol / Q000494:pharmacology*; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007985:Leydig Cells / Q000378:metabolism*; D008297:Male; D010795:Phthalic Acids / Q000494:pharmacology*; D011506:Proteins / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism*
chemical_list: D007328:Insulin; C084797:Leydig insulin-like protein; D010795:Phthalic Acids; D011506:Proteins; D013739:Testosterone; D004958:Estradiol; D004051:Diethylhexyl Phthalate; C016599:mono-(2-ethylhexyl)phthalate; C028577:monobutyl phthalate