title: A two-generation reproductive toxicity study of 2,4-dichlorophenol in rats.
abstract: A two-generation reproductive toxicity study was conducted with 2,4-dichlorophenol (2,4-DCP), an agent suspected of exerting endocrine disrupting effects. Wistar-Hannover rats, 24/sex/group, were given diet containing 2,4-DCP at dose levels of 0, 500, 2000 or 8000 ppm to examine the potential effects of the test substance on parental animals and their offspring over 2 successive generations. Neither clear systemic nor reproductive toxicity of 2,4-DCP was apparent in the 500 ppm group. In the 2000 ppm group, mean body weight gain and food consumption of females were lowered significantly during the treatment period. Effects on body weights and food consumption were more serious in the 8000 ppm group, both males and females being significantly affected. Reproductive effects of the test substance were also observed in the 2000 and 8000 ppm groups dose-dependently. Observations included significantly increased uterine weights of F1 and/or F2 female weanlings and reduced numbers of implantation sites and live births of F1 parental females. These results suggest that 2,4-DCP has weak reproductive toxicity, possibly based on endocrine activity. However, the basic mechanisms for apparent estrogenic effects of 2,4-DCP remain to be elucidated.
authors.affiliation: Laboratory of Reproductive Toxicology, Chemistry Division , Institute of Environmental Toxicology, 4321 Uchimoriya-machi, Mitsukaido-shi, Ibaraki 303-0043, Japan. aoyama@iet.or.jp
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Aoyama
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hojo
authors.forename: Ken L
authors.initials: KL
authors.lastname: Takahashi
authors.forename: Naoko
authors.initials: N
authors.lastname: Shimizu
authors.forename: Masayuki
authors.initials: M
authors.lastname: Araki
authors.forename: Michiko
authors.initials: M
authors.lastname: Harigae
authors.forename: Naoki
authors.initials: N
authors.lastname: Tanaka
authors.forename: Noriko
authors.initials: N
authors.lastname: Shirasaka
authors.forename: Maki
authors.initials: M
authors.lastname: Kuwahara
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Nakashima
authors.forename: Eri
authors.initials: E
authors.lastname: Yamamoto
authors.forename: Machiko
authors.initials: M
authors.lastname: Saka
authors.forename: Shoji
authors.initials: S
authors.lastname: Teramoto
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002733:Chlorophenols / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D052244:Endocrine Disruptors / Q000633:toxicity*; D005260:Female; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced*; D051381:Rats; D011919:Rats, Inbred Strains; D012098:Reproduction / Q000187:drug effects*; D036401:Toxicity Tests, Chronic / Q000379:methods*
chemical_list: D002733:Chlorophenols; D052244:Endocrine Disruptors; C004762:2,4-dichlorophenol