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T R Hanley

Publications and source records attributed to T R Hanley.

30 records · Page 2Linked to original sources
PubMed1984

Inhalation teratology study on monochlorobenzene in rats and rabbits.

The embryotoxic and teratogenic potential of inhaled monochlorobenzene (MCB) was evaluated in rats and rabbits. Bred Fischer 344 rats and inseminated New Zealand White rabbits were exposed to 0, 75, 210, or 590 ppm of MCB via inhalation for 6 hr/day during the period of major organogenesis. Exposure to 590 ppm caused elevated liver weights in both species and decreased body weight gain and feed consumption in rats. Inhalation of MCB vapors during gestation was not embryotoxic or teratogenic in rats. In rabbits, a few MCB-exposed fetuses exhibited visceral malformations which were not observed among concurrent controls, though no dose-related increase in malformations occurred. To further evaluate the effects of MCB in rabbits, additional groups were exposed to 0, 10, 30, 75, or 590 ppm. This subsequent study did not result in any increase in malformations in the MCB-exposed groups. Fetal effects were limited to a slight delay in skeletal development which occurred only in rats exposed to 590 ppm, a maternally toxic concentration.

Abnormalities, Drug-Induced↗
PubMed1984

Teratologic evaluation of inhaled propylene glycol monomethyl ether in rats and rabbits.

Pregnant Fischer 344 rats and New Zealand White rabbits were exposed via inhalation to 0, 500, 1500, or 3000 ppm of propylene glycol monomethyl ether (PGME) for 6 hr/day on Days 6 through 15 (rats) or 6 through 18 (rabbits) of gestation. Initial exposure to 3000 ppm of PGME produced signs of mild central nervous system depression which were more pronounced and of a longer duration in rats than in rabbits. Postexposure recovery was rapid and accomodation to the test atmosphere developed following subsequent exposures. Rats and rabbits exposed to 3000 ppm had decreased weight gains over the exposure period and rats had decreased food consumption during the first 3 days of exposure. Fetal examination revealed no embryotoxic or teratogenic effects among rats or rabbits in any exposure group. Slight fetotoxicity among rats, in the form of delayed sternebral ossification, was observed at 3000 ppm. Thus, it was concluded that PGME was not teratogenic at exposure levels up to 3000 ppm.

Abnormalities, Drug-Induced↗
PubMed1984

Teratology and reproduction studies with triclopyr in the rat and rabbit.

Triclopyr (3,5,6-trichloro-2-pyridyloxyacetic acid), being developed as a new herbicide for use on brush and weeds, was evaluated for its potential effects on reproduction, and embryonal and fetal development. Pregnant Sprague-Dawley rats were given doses of 0, 50, 100, or 200 mg/kg/day by gavage on Days 6 through 15 of gestation. Dose-related signs of maternal toxicity were observed during the treatment period. No teratogenic effects were observed at any dose level, though slight fetotoxicity, possibly secondary to maternal toxicity, occurred at the high dose level (200 mg/kg/day). Pregnant New Zealand White rabbits were given doses of 0, 10, or 25 mg/kg/day by gavage on Days 6 through 18 of gestation which produced transient, dose-related decreases in maternal body weight gain. However, there were no indications of any treatment-related effects on fetal growth and development among rabbits. Male and female Sprague-Dawley rats maintained on diets supplying 0, 3, 10, or 30 mg/kg/day over three generations exhibited no consistent treatment-related effects on reproductive performance, pregnancy, parturition, or neonatal survival. These data indicated that triclopyr had little or no potential for teratogenic or reproductive toxicity even when the level of exposure approached that which elicited maternal toxicity.

Abnormalities, Drug-Induced↗
PubMed1984

Ethylene glycol monomethyl ether (EGME) and propylene glycol monomethyl ether (PGME): inhalation fertility and teratogenicity studies in rats, mice and rabbits.

A combined dominant lethal-fertility study was conducted in which male and female Sprague-Dawley (CD) rats were exposed to 0, 30, 100 or 300 ppm of ethylene glycol monomethyl ether (EGME) vapor for 6 hr/day, 5 days/week for 13 weeks and then mated to untreated counterparts. Among males, fertility was completely suppressed after exposure to 300 ppm. A partial restoration of reproductive function was evident following 13 weeks of recovery. No treatment-related reproductive effects were observed among males exposed subchronically to 100 ppm, or among females exposed to 300 ppm or below of EGME. Studies to assess the effects of inhaled EGME on embryonal and fetal development were also conducted in Fischer 344 rats, CF-1 mice, and New Zealand White rabbits. Rats and rabbits were exposed to concentrations of 0, 3, 10 or 50 ppm for 6 hr/day on days 6-15 or 6-18 of gestation, respectively. Exposure of rabbits to 50 ppm resulted in significant teratologic effects, an increased resorption rate, and decreased fetal body weight. Slight fetotoxicity in the form of skeletal variations were observed among rats exposed to 50 ppm. Exposure of pregnant mice to 0, 10, or 50 ppm for 6 hr/day on days 6-15 of gestation resulted in slight fetotoxicity at 50 ppm. No significant treatment-related effects were observed at 10 ppm of EGME or below in any of the species tested. Separate groups of pregnant rats and rabbits were exposed to 0, 500, 1500 or 3000 ppm of propylene glycol monomethyl ether (PGME) during organogenesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1981

Teratogenic effects of vitamin A palmitate in Fischer 344 rats.

Prior to employing the Fischer 344 rat in teratology studies, it was considered necessary to establish the responsiveness of this strain to teratogenic agents. Bred Fischer 344 rats were administered 0, 3.2, 32, or 128 mg/kg/day (approximately 1,000, 10,000, or 40,000 USP units per animal) of vitamin A palmitate by gavage on days 6 through 15 of gestation. Maternal toxicity, as evidenced by decreased body weight gain, and decreased food and water consumption, was observed at the 128 mg/kg/day dose level. This dosage level was embryolethal and teratogenic in the Fischer 344 rat. The incidence of fetal resorptions was statistically significantly increased as compared to controls. Among the surviving fetuses, malformations observed included cleft palate, exencephaly, microphthalmia, anophthalmia, hydronephrosis, brachygnathia, pinna anomalies, and great vessel and heart anomalies. Based on these findings, it is concluded that the Fischer 344 rat responded to a known teratogenic agent and hence is appropriate for use in studies designed to evaluate the teratogenic potential of test agents.

Animals↗
PubMed1981

Triethylenemelamine (TEM): dominant lethal effects in Fischer 344 rats.

Male Fischer 344 rats were administered triethylenemelamine orally at dose levels of 0, 0.5 or 1.0 mg TEM/kg/day, five days per week for four weeks. A separate group of males was administered TEM as a single intraperitoneal injection of 0.3 mg/kg. Following treatment, males were mated with two groups of untreated females for a period of one week each. The uterine contents of untreated females were examined for evidence of a dominant lethal effect as manifested in an increase in the average resorption rate. Significant increases in the resorption rate were seen at 0.5 mg/kg/day for the second breeding period, and at 1.0 mg/kg/day for both breeding periods following oral administration. Significant decreases in the number of implantations, and increases in the average pre-implantation loss and resorption rate were observed following intraperitoneal administration. These effects seen in Fischer 344 rats were comparable to results obtained with other strains following a similar treatment regimen.

Animals↗
PubMed1980

2-Isocyanatoethyl methacrylate--an inhalation dominant lethal study in the male Sprague-Dawley rat.

2-Isocyanatoethyl methacrylate (IEM), a monomer, has been developed for use as a component in coating materials. The dominant lethal test was used to evaluate the mutagenic potential of IEM in rats. In this study, male Sprague-Dawley rats were exposed to 0, 25, 80, or 250 ppb of IEM by inhalation for 6 hr/day for 10 weeks (one spermatogenic cycle). After the exposure period, the males were bred with untreated virgin female rats. At approximately mid-gestation, the females were sacrificed and the number of corpora lutea, implantations, and resorptions were recorded. Statistical analysis of these data indicated that the treated males were comparable to control males in all reproductive parameters evaluated. IEM did not affect male fertility or produce dominant lethal mutations in male rats following ten weeks of inhalation exposure to 25, 80 or 250 ppb IEM.

Acrylates↗
PubMedDate not supplied

Teratologic evaluation of inhaled epichlorohydrin and allyl chloride in rats and rabbits.

Pregnant Sprague-Dawley rats and New Zealand white rabbits were exposed to vapors of epichlorohydrin (ECH) at concentrations of 0, 2.5 or 25 ppm or to allyl chloride (AC) at concentrations of 0, 30, or 300 ppm. Exposures were for 7 hr/day on days 6 through 15 (rats) or 6 through 18 (rabbits) of gestation. Maternal effects including decreased body weight and food consumption were observed among rats inhaling 25 ppm of ECH. No evidence of an adverse effect to the embryo or fetus was observed among rats or rabbits following exposure to ECH. In the AC study maternal toxicity occurred in both rats and rabbits treated at 300 ppm. These consisted of depressed weight gain during gestation and increases in liver weight (both species) and kidney weights (rats only). Fetuses from rats exposed to 300 ppm of AC had a slight delay in skeletal development but there were no other signs of embryotoxicity. Thus, ECH and AC were not teratogenic or embryolethal in rats or rabbits following inhalation exposure to concentrations which induced effects in the maternal animals.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

Ethylene glycol monomethyl ether II. Reproductive and dominant lethal studies in rats.

Groups of male and female Sprague-Dawley (CD) rats were exposed to 0, 30, 100, or 300 ppm ethylene glycol monomethyl ether (EGME) vapor 6 hours/day, 5 days/week for 13 weeks. The 0 and 30 ppm groups each contained 30 rats/sex and the 100 and 300 ppm groups each had 20 rats/sex. Following the exposure period, males were bred to unexposed females to evaluate reproductive capability and dominant lethality. Additional matings of control and 300 ppm exposed males were performed during the post-exposure period in order to evaluate the recovery of fertility. Exposed females were bred with unexposed males to assess reproductive parameters. Results of the present study indicate a potential for inhaled EGME to completely suppress fertility in male rats at the 300 ppm level. Fertility of these rats was partially restored at 13 weeks post-exposure. Body weights of animals in the 300 ppm group were reduced as a result of the exposures. No dominant lethal effect or impaired fertility was observed in male rats exposed to 30 or 100 ppm EGME. Treatment-related pathologic alterations were observed only in male rats at the 300 ppm level and induced decreased testicular size and atrophic seminiferous tubules. Female rats tolerated up to 300 ppm EGME without any adverse reproductive effects. Based on these results, it was concluded that the no-adverse effect level of EGME for fertility and reproduction was 100 ppm in rats.

Animals↗