| Abstract |
Based on information provided in the dose range-finding study, timed-pregnant CD(TradeName) (Sprague-Dawley) rats were exposed to the test chemical, Tergitol NP-4 Surfactant, dissolved in corn oil and administered by gavage once daily on gestational days (gd) 6 through 15, at doses of 0, 50, 250, or 500 mg/kg/day (equivalent to 0.0, 50.0, 250.0, and 500.0 mg/ml, at a dosing volume of 1.0 ml/kg). There were 25 sperm-positive females per group. The dosing volume was adjusted based on each animal's most recent body weight. Clinical observations were taken daily, except during the dosing period when they were made at least twice daily. Maternal body weights were taken on gd 0, 6, 9, 12, 15, 18, and 20. Feed consumption was measured for the intervals gd 0-6, 6-9, 9-12, 12-15, 15-18, and 18-20. At scheduled sacrifice on gd 20, the dams were evaluated for body, liver, and gravid uterine weights. Ovarian corpora lutea were counted, and the status of uterine implantation sites (i.e., resorptions, dead fetuses, live fetuses) was recorded. All fetuses were dissected from the uterus, counted, weighed, sexed, and examined for extemal abnormalities. Approximately one-half of the live fetuses in each litter were examined for visceral malformations and variations. These fetuses were decapitated and the heads fixed in Bouin's solution; serial free-hand sections of the heads were examined for soft tissue craniofacial malformations and variations. AII fetuses in each litter were eviscerated, fixed in alcohol, and stained with alizarin red S/alcian blue. Intact fetuses (approximately one-half per litter, not decapitated) were examined for skeletal malformations and variations. |
