• Toxicological Research
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• v.16 no.2
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• pp.163-172
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• 2000

Recently, there is a worldwide concern that a great number of man-made chemicals have a hormone-like action both in humans and in animals. DECD is developing screening programs using validated test systems to determine whether certain substances may have an effect in humans. In the present study. the establishment oj repeated-dose toxicity test method was tried. Flutamide. an anti-androgenic agent. was administered by gavage to Sprague-Dawley rats for 28 days at dose levels of 0. 0.5. 3 and 18 mg/kg body weight (10-15 rats/sex/group) to examine the effects on general findings. especially reproductive and endocrine parameters. Clinical signs. body weights, food consumption, and sexual cycle were checked and measured. For the gross and microscopic examinations. 10 rats/sex/group were sacrificed at the end of dosing period and the remaining animals of control and high dose groups (5 each) were sacrificed after 14 days recovery. Examinations for hematology and clinical chemistry were carried out at necropsy. There were no treatment-related changes in clinical signs. body weights, food consumption. gross necropsy. hematology and clinical chemistry at all doses of both sexes. The period and regularity of sexual cycle were not adversely affected at all doses by the test agent. At 18 mg/kg. both decreased weights of prostate, seminal vesicle and epididymis in males and increased weights of spleen and thymus in females were observed. In addition, decreased number of spermatids and sperms. increased serum testosterone concentration and increased incidence (100%) of interstitial cell hyperplasia were seen in males. At 18 mg/kg of the recovery group. decreased prostate weight. reduced sperm count and increased incidence (20%) of interstitial cell hyperplasia in males and increased thymus weight in females were observed. At 3 mg/kg. reduced sperm count was found. There were no adverse effects on parameters examined at 0.5 mg/kg of both sexes. The results suggested that the potential target organs of flutamide may be accessory sexual glands including testes for males and spleen and thymus for females. Taken together. this test method was found to be a useful screening test system for endocrine disrupting chemicals.

• Biomolecules & Therapeutics
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• v.2 no.1
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• pp.82-93
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• 1994

DA-125, a new anthracycline antitumor antibiotic, was at dose levels of 0, 0.1, 0.3 and 1.0 mg/kg/day administered intravenously to pregnant Sprague-Dawley rats during the organogenetic period. Two-third of dams per group were subjected to caesarean section on day 20 of pregnancy and the remaining 10 dams per group were allowed to deliver. Effects of test substance on dams, embryonal development of Fl fetuses, as well as growth, behaviour and mating performance of Fl offspring were examined. 1. At 1 mg/kg, one out of the 10 dams showed difficult delivery. A decrease in food consumption, a loss in body weight and a decrease of spleen weight were found in this dose level group. At 0.3 mg/kg, difficult deliverys were observed in two out of the 10 dams. 2. At 1 mg/kg, an increased resorption rate and a decreased fetal weight were found. In addition, various types of external, visceral and skeletal malformations occurred at an incidence of 11.9, 41.8 and 14.5%, respectively. 3. At 1 mg/kg, body weight reduction, small eyeball, hydrocephalus and atrophy of sexual organs were observed in Fl offspring. One male pup receiving 0.3 mg/kg died on day 2 of lactation. The results show that the no-effect dose levels (NOELs) for dams and Fl offspring are 0.1 mg/kg/day and NOEL for Fl fetuses is 0.3 mg/kg/day.