• This is because several of the contaminants in technical grade methoxychlor are directly estrogenic (Kupfer and Bulger 1987b), whereas pure methoxychlor is proestrogenic and requires metabolic activation before exhibiting estrogenic activity (Bulger et al. (cdc.gov)
  • Some of the estrogenic contaminants of technical grade methoxychlor are the same as those formed by metabolism in vivo (Bulger et al. (cdc.gov)
  • 1980. Toxicity and bioaccumulation of endrin and methoxychlor in aquatic invertebrates and fish. (cdc.gov)
  • In vivo exposure of young adult male rats to methoxychlor reduces serum testosterone levels and ex vivo Leydig cell testosterone formation and cholesterol side-chain cleavage activity. (cdc.gov)
  • Although in vitro studies using cultured rat Leydig cells have reported that HPTE inhibits both basal and hCG-stimulated testosterone formation, the response of circulating testosterone levels to in vivo MC has been more variable. (cdc.gov)
  • Therefore, the current studies evaluated whether the daily in vivo administration of MC (0, 5, 40 and 200mg/kg body weight) for a short duration (days 54-60 of age) by gavage altered serum testosterone levels and ex vivo Leydig cell testosterone formation in young adult male rats. (cdc.gov)
  • Ex vivo Leydig cell basal testosterone formation over 4h declined to 49% of control in animals exposed to 200mg/kg MC, and ex vivo Leydig cell P450 cholesterol side-chain cleavage activity declined to 79 and 50% of control in animals exposed to 40 and 200mg/kg of MC, respectively, supporting previous in vitro studies which demonstrated the sensitivity of this step to MC. (cdc.gov)
  • 2000. A metabolite of methoxychlor, 2,2-bis( p hydroxyphenyl)-1,1,1-trichloroethane, reduces testosterone biosynthesis in rat leydig cells through suppression of steady-state messenger ribonucleic acid levels of the cholesterol side-chain cleavage enzyme. (cdc.gov)
  • 1974. Pesticidal chemicals affecting some energy-linked functions of rat liver mitochondria in vitro . (cdc.gov)
  • 1964). In vitro metabolism by hepatic microsomal enzymes from rats treated 8 days previously with single i.p. doses of 10 or 100 mg/kg of chlordane in corn oil was increased for the 3 drugs reported (hexobarbital, aminopyrine and chlorpromazine). (inchem.org)
  • 1953). It is stored in the adipose tissue of rats, sheep, goats, and cows and accumulates in the milk. (inchem.org)
  • 1963). Both technical chlordane and one of its pure isomers (gamma-chlordane) have been shown to have stimulating effects on rat liver microsomes for the metabolism of certain drugs (Burns et al. (inchem.org)
  • 1999. Methoxychlor given in the pre- implantation period blocks sexual arousal in male mice. (cdc.gov)
  • For this reason, the chemical purity of the methoxychlor used in key quantitative studies is provided. (cdc.gov)
  • The purpose of this study was to examine the sensitivity of the pubertal assay to an estrogen (Methoxychlor), anti-androgen (Vinclozolin and Flutamide), and a thyroid-active agent (Phenobarbital) in intact juvenile/peripubertal male and female rats. (nih.gov)
  • The lowest observable effect level (LOEL) for an endocrine effect was 25 mg/kg/day for Flutamide, 10 mg/kg/day for Vinclozolin, 100 mg/kg/day for Phenobarbital, 12.5 mg/kg/day for Methoxychlor, and 0.005 mg/kg/day for Ethinyl Estradiol. (nih.gov)
  • In a receptor-binding assay, butylparaben was able to compete with 3H-estradiol for binding to the rat estrogen receptor with an affinity approximately 5 orders of magnitude lower than that of diethylstilboestrol, and between 1 and 2 orders of magnitude less than nonylphenol. (researchgate.net)
  • When administered orally to immature rats, the parabens were inactive. (researchgate.net)
  • The immature rat model was used for 76% of the GL studies. (nih.gov)
  • 2000. The effect of raloxifene on the uterine weight response in immature mice exposed to 17- estradiol, 1,1,1-trichloro-2,2- bis ( p -chlorophenyl)ethane, and methoxychlor. (cdc.gov)
  • In this study, the effects of prenatal exposure to deltamethrin on learning and memory abilities, N -methyl- D -aspartate receptor (NMDAR) subunits, brain derived neurotrophic factor (BDNF), Tyrosine kinase B (TrkB) receptor, and phosphorylated cAMP response element binding protein (pCREB) in the hippocampus of offspring rats were investigated. (frontiersin.org)
  • 1974. Pesticidal chemicals affecting some energy-linked functions of rat liver mitochondria in vitro . (cdc.gov)
  • Fifty-five time-mated female (F0) Sprague Dawley Rats were received from Charles River Laboratories and allowed to litter at TherImmune. (nih.gov)
  • Groups each of six female SD rats, as F0-generation, were administered with deltamethrin (0, 0.54, 1.35, and 2.7, 9 mg/kg), or memantine (10 mg/kg), or co-administered with deltamethrin (9 mg/kg) and memantine (10 mg/kg) daily by gavage during pregnancy. (frontiersin.org)
  • The primary purpose of this chapter is to provide public health officials, physicians, toxicologists, and other interested individuals and groups with an overall perspective on the toxicology of methoxychlor. (cdc.gov)