Developmental effects of plasticizer butyl benzyl phthalate after a singleadministration in rats

The objective of this study was to determine the susceptible day for the de velopmental toxicity of butyl benzyl phthalate (BBP) by a single administra tion on one of the days during organogenesis, Pregnant rats were given a si ngle dose of BBP by gastric intubation at a dose of 1000 mg kg(-1) on one o f days 13-15 of pregnancy and at 1500 mg kg(-1) on one of days 6-16 of preg nancy. Post-implantation embryolethality was found in pregnant rats given o n one of days 6-16, except for day 7. Teratogenicity was noted after a sing le dosing of BBP on one of days 6, 7, 9, 10, 12, 14 and 15. Deformity of th e cervical vertebrae frequently was observed after administration of BBP on day 7, Cleft palate and fusion of the sternebrae were found exclusively, a fter administration of BBP on day 15, It can be concluded that the manifest ation of deviant development induced by BBP varies with the developmental s tage at the time of administration and that BBP induces two discrete respon ses from embryos to teratogenicity during early and late organogenesis. Cop yright (C) 1999 John Whey & Sons, Ltd.