Showing papers in "Toxicology and Applied Pharmacology in 1989"

TL;DR: A gas-phase vial equilibration technique is presented for determining the liquid: air and tissue:air partition coefficients for low-molecular-weight volatile chemicals and an approach is described for predicting the tissue solubilities of untested compounds based on oil:air and saline:air coefficients using regression analyses.

TL;DR: It is demonstrated that PCB congeners with ortho-chlorine substitution, and which are effective inducers of AHH and EROD activity in mammals, are ineffective, at the doses tested, as inducers in the teleost scup.

TL;DR: This sustained increase in renal cell proliferation can promote initiated cells to form preneoplastic foci and renal neoplasia in male rats, and it is important to determine the relevance of these data for human risk assessment.

TL;DR: It is concluded that the effect of phenobarbital on thyroid function in rats is primarily a result of its effects on the hepatic disposition of thyroid hormone, and the induction of thyroxine-glucuronyltransferase appears to play an important role in the increased metabolism and excretion of Thyroxine in phenobarBital-treated rats.

TL;DR: Kinetics in the pregnant rat exposed to TCE by inhalation, by bolus gavage, or by oral ingestion in drinking water are described and the fetus is clearly at risk both to parent TCE and its TCA metabolite.

TL;DR: The results demonstrate that an appropriate receptor fluid, such as MEM, HHBSS, or DMPBS, is required for percutaneous absorption studies in which cutaneous metabolism of the penetrating compound is to be considered.

TL;DR: Estimating the in vivo rates of metabolism of CH2Cl2 from in vitro incubations of lung and liver tissues from B6C3F1 mice, F344 rats, Syrian Golden hamsters, and humans is reported and a procedure for calculating in vivo metabolic rate constants from the in vitro studies is presented.

TL;DR: It is suggested that isozyme 3a (P450IIE1) is a low-Km benzene hydroxylase and the principal phenol hydroxyase in rabbit hepatic microsomes and could potentiate the toxicity of benzene by catalyzing an increase in the formation of both phenol and hydroquinone.

TL;DR: The results indicated that degeneration of cellular membranes is an early cellular effect of cadmium exposure followed later by toxicity to organelles, cellular necrosis, and interstitial fibrosis.

TL;DR: D-Limonene, and more specifically d-limonene-1,2-oxide, associates with alpha 2u-globulin in a reversible manner in male rat kidney, which may be responsible for excessive accumulation of alpha 2U-glOBulin in kidneys of male rats exposed to d- Limonene.

TL;DR: Comparative long-term studies in poorly responsive species, such as the guinea pig and marmoset, may help clarify the role of organelle proliferation in the hepatocarcinogenicity of certain peroxisome proliferators.

TL;DR: The biological aspects of the induction of lysosomal lamellar bodies by drugs are examined and the toxicologic implications of their presence in cells are considered.

TL;DR: It is proposed that deregulation of ions, especially [Ca2+]i, plays an important role, if not a key role, in the initiation of acute and chronic cell injury, including neoplasia.

TL;DR: It is demonstrated that the mouse is more sensitive than the rat with respect to the enhancement of liver peroxisome proliferation by TCA and DCA and suggested that the rat should be less sensitive or refractory to tumor induction.

TL;DR: Whether the exposure begins on GD 10 or 12 or whether the dosing level produces only a few cleft palates within a litter, TCDD produced cleft palate by altering the differentiation program of the medial cells.

TL;DR: A model for a facilitated transport of the all-trans forms to the developing embryo is proposed and it is suggested that the conversion to the trans isomer and trans metabolite could play a major role in the teratogenicity of 13-cis-retinoic acid in humans.

TL;DR: The results indicated a shift in metabolism from putative toxification pathways to detoxification pathways as the exposure concentration or oral dose increased, and a species difference in benzene metabolism.

TL;DR: It is suggested that chronic cell proliferation associated with alpha 2uG nephropathy and CPN in male rats exposed to UG or isoparaffinic components of UG, such as TMP, may be responsible for the sex- and species-specific nephrocarcinogenic effects of Ug.

TL;DR: There were no specific findings in heart or lung tissue from aluminum-treated rabbits, although the aluminum content of these tissues was 10 to 20 times greater than control values, which should be useful for investigating the effects of systemic exposure to high concentrations of solubilized aluminum.

TL;DR: Model simulations suggested that for both rats and mice at lower exposure concentrations hydroquinone and muconic acid represented a larger fraction of the total benzene metabolized than at higher exposure concentrations where detoxification metabolites were predominant.

TL;DR: In this article, the authors showed that at doses as high as 750 to 1000 mumol/kg, 2,2,4,4 5,5,5-,hexachlorobiphenyl (HCBP) did not cause fetal cleft palate, suppress the splenic plaque-forming cell response to sheep red blood cells, or induce hepatic microsomal EROD in C57BL/6J mice.

TL;DR: The results of these studies demonstrate a good in vivo/in vitro correlation for the effects of coumarin and dihydrocoumarin in rat hepatocytes and suggest that cou marin hepatoxicity in the rat is due to coumar in bioactivation by cytochrome P450-dependent enzymes to a toxic metabolite(s), which may be a coumarIn 3,4-epoxide intermediate.

TL;DR: The morphological phenomenon of peroxisome proliferation should serve as a simple, sensitive, and valuable biological indicator for the identification of nongenotoxic or nonmutagenic chemicals that may be carcinogenic.

TL;DR: Nephrotoxicity and biochemical alterations induced by 1,4-DCB resemble those of unleaded gasoline and suggest that a similar mechanism is involved in the induction of α 2u -globulin nephropathy in male rats.

TL;DR: A low rate of liver metabolism such as that found for caffeine, salicylic acid, and DDT might often be predictive of the absence of measurable metabolism during skin permeation.

TL;DR: A specific site of action of MEHP in vitro which may be related to the in vivo testicular toxicity of phthalate esters is described, which is independent of the inhibitory adenylate cyclase pathway.

TL;DR: The data indicate that lindane may effectively block the response of estrogen-dependent tissues to this ovarian steroid hormone and that this apparent antiestrogenic effect of lINDane is responsible for the disturbances observed in the neuroendocrine control of ovarian function in the rat.

TL;DR: Combination treatment of TCDD and RA resulted in a synergistic response that varied with the stage of development and was tissue specific, suggesting some similarities in mechanism between the two compounds.

TL;DR: Metal complexes of meso-dimercaptosuccinic acid (DMSA) with Pb2+, Cd2+, and Hg2+ were studied by potentiometric and infrared methods and diMe-meso-DMSA, when given to rats 3 days after Cd administration, greatly increased the excretion of Cd via bile.

TL;DR: The data show that short-term MXC dosing during early pregnancy produces a dose-related infertility, and the bloickade of pregnancy by the preimplantation administration of MXC may be mediated by a direct effect on preim implantation uterine development.