National Toxicology Program technical report series
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Natl Toxicol Program Tech Rep Ser · Mar 2008
Multigenerational reproductive study of genistein (Cas No. 446-72-0) in Sprague-Dawley rats (feed study).
Genistein is a naturally occurring isoflavone that interacts with estrogen receptors and multiple other molecular targets. Human exposure to genistein is predominantly through consumption of soy products, including soy-based infant formula and dietary supplements. Consumption of soy and genistein has been associated with a variety of beneficial effects in animals and humans, but concerns have also been raised concerning potential adverse effects of genistein, particularly with regard to reproductive toxicity and the induction or potentiation of carcinogenesis, due primarily to its weak estrogenic activity. ⋯ The minimal exposure to genistein during this critical developmental period must be considered in the interpretation of the data derived from the current study. In summary, although genistein did show adverse effects with dietary exposures of 100 or 500 ppm, there were no clear adverse effects on the reproductive or developmental parameters measured at genistein concentrations ranging from less than 1 ppm (control diet) to 100 ppm, a range of doses producing serum concentrations achievable from the phytoestrogen content of human diets. There were few clear, overtly toxic effects that carried over across directly exposed generations or appeared to be imprinted to carry over into unexposed descendents under the conditions of exposure in this study. (ABSTRACT TRUNCATED).
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Natl Toxicol Program Tech Rep Ser · Mar 1997
NTP Toxicology and Carcinogenesis Studies of Scopolamine Hydrobromide Trihydrate (CAS No. 6533-68-2) in F344 Rats and B6C3F1 Mice (Gavage Studies).
Scopolamine hydrobromide trihydrate is used in ophthalmic preparations and as a preanesthetic sedative. Its major use is in transdermal patches for the treatment of motion sickness. Scopolamine hydrobromide trihydrate was selected for study because of considerable human exposure resulting from its use in prescription and over-the-counter preparations. ⋯ Despite the evidence for chromosomal damage observed in vitro, no increase in the frequencies of micronucleated normochromatic erythrocytes was observed in peripheral blood samples of male or female mice exposed to scopolamine hydrobromide trihydrate for 14 weeks by gavage. Under the conditions of these 2-year gavage studies, there was no evidence of carcinogenic activity of scopolamine hydrobromide trihydrate in male or female F344/N rats or B6C3F1 mice administered 1, 5, or 25 mg/kg. Synonyms: Scopolamine hydrobromide, 6,7-epoxytropan-3-yl, euscopol, hydroscine hydrobromide, hyoscine bromide, (-)-hyoscine hydrobromide, hysco, isoscopil, scopolammonium bromide, (s)-tropate hydrobromide trihydrate, lα-tropyl-a-scopine
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Natl Toxicol Program Tech Rep Ser · Sep 1998
NTP Toxicology and Carcinogenesis Studies of Chloroprene (CAS No. 126-99-8) in F344/N Rats and B6C3F1 Mice (Inhalation Studies).
Chloroprene is used almost exclusively in the manufacture of neoprene (polychloroprene). Chloroprene was chosen for study because it is a high-volume production chemical with limited information on its carcinogenic potential and because it is the 2-chloro analogue of 1,3-butadiene, a potent, multi-species, multi-organ carcinogen. Male and female F344/N rats and B6C3F1 mice were exposed to chloroprene (greater than 96% pure) by inhalation for 16 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, Drosophila melanogaster, and B6C3F1 mice (bone marrow cells and peripheral blood erythrocytes).
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Natl Toxicol Program Tech Rep Ser · Dec 1993
NTP Toxicology and Carcinogenesis Studies of Triamterene (CAS No. 396-01-0) in F344/N Rats and B6C3F1 Mice (Feed Studies).
Triamterene is a potassium-sparing diuretic used in the treatment of edema associated with congestive heart failure, cirrhosis of the liver, and other diseases in which edema may occur. Toxicity and carcinogenicity studies were conducted by administering triamterene (greater than 99% pure) in feed to groups of male and female F344/N rats and B6C3F1 mice for 15 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and Chinese hamster ovary cells. 15-day Studies: Groups of five male and five female rats were fed diets containing 0, 1,000, 3,000, 10,000, 30,000, or 60,000 ppm triamterene. ⋯ Exposure to triamterene was associated with an increased incidence of hepatocellular foci, primarily mixed cell type, and an increase in the severity of nephropathy in female rats. In mice, exposure to triamterene was associated with an increased incidence of hepatocellular foci in females and an increased incidence of thyroid gland follicular cell hyperplasia in males and females. Synonyms: 6-Phenyl-2,4,7-pteridinetnamine; 6-phenyl-2,4,7-triaminopteridine; 2,4,7-triamino-6-phenypteridine; ademin; pterofen; pterophane; NSC-77625; SKF 8542 Trade names: Dyrenium, Dyazide, Dyren, Dytac, Jatropur, Maxzide, Noridyl, Triteren, Teriam, Urocaudal
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Natl Toxicol Program Tech Rep Ser · Aug 1993
NTP Toxicology and Carcinogenesis of 1,2,3-Trichloropropane (CAS No. 96-18-4) in F344/N Rats and B6C3F1 Mice (Gavage Studies).
1,2,3-Trichloropropane is a colorless liquid used as a paint and varnish remover, solvent, and degreasing agent, and as a crosslinking agent in the synthesis of polysulfides and hexafluoropropylene. 1,2,3-Trichloropropane may be found as an impurity in certain nematocides and soil fumigants and as a contaminant of drinking and ground water. Studies on the toxic and carcinogenic effects of 1,2,3-trichloropropane were initiated because of the close structural relationship of this chemical to other short-chain halogenated compounds that were demonstrated to be carcinogenic in experimental animals, and because of the potential for human exposure. Toxicology and carcinogenicity studies were conducted by administering 1,2,3-trichloropropane (greater than 99% pure) in corn oil by gavage to groups of F344/N rats and B6C3FI mice for 17 weeks and 2 years. ⋯ Nonneoplastic lesions associated with exposure to 1,2,3-trichloropropane included increased severity of nephropathy in male rats and increased incidences of basal cell and squamous hyperplasia of the forestomach, acinar hyperplasia of the pancreas, renal tubule hyperplasia, and preputial or clitoral gland hyperplasia in male and female rats. Increased incidences of squamous hyperplasia of the forestomach and eosinophilic foci in the liver in male and female mice were chemical related. Synonyms: Allyl trichloride, glycerol tnchlorohydrin, glyceryl tnchlorohydrin, trichlorohydrin