Simultaneous monitoring of carbamazepine and its metabolities is helpful in providing information on the induction process via the epoxide-diol route. The present method involves the liquid-chromatographic analysis of 1.0 mL of plasma for carbamazepine at concentrations of 0.025 to 4.0 mg/L and for both the 10,11-epoxide and 10,11-transdiol metabolites at concentrations of 0.01 to 1.0 mg/L. Wei...

Polycyclic aromatic hydrocarbons (PAHs) are significant environmental pollutants representing an important risk factor in human cancers. DNA adducts formed by the ultimate carcinogens of PAHs are potentially toxic, mutagenic and carcinogenic. DNA repair represents an important defense system against these genotoxic insults. Using a human cell-free system we have examined repair of DNA lesions i...

Hepatic Microsomal Epoxidation of Bromobenzene to Phenols and Its Toxicological Implication. LAU, S. S. AND ZANNONI, V. G. (1979). Toxicol. Appl. Pharmacol. 50, 309318. In vitro microsomal hepatic epoxidation of bromobenzene in rats and mice is presented in this study. Formation of o-bromophenol via bromobenzene-2,3-epoxide and p-bromophenol via bromobenzene-3,4-epoxide was assayed enzymaticall...

The pioneering work of Gerry Brooks on cyclodiene insecticides led to the discovery of a class of enzymes known as epoxide hydrolases. The results from four decades of work confirm Brooks' first observations that the microsomal epoxide hydrolase is important in foreign compound metabolism. Brooks and associates went on to be the first to carry out a systematic study of the inhibition of this en...

The interaction of dibenz[a,h]anthracene and its ultimate carcinogenic 3,4-diol-1,2-epoxide with lung surfactant phospholipid bilayers was successfully performed using molecular dynamics. The DPPC/DPPG/cholesterol bilayer (64 : 64 : 2) was used as the lung surfactant phospholipid bilayer model and compared with the DPPC bilayer as a reference. Dibenz[a,h]anthracene and its 3,4-diol-1,2-epoxide ...

Several previously identified inhibitors of angiogenesis have been epoxide-containing fungus-derived metabolites. We therefore hypothesized that novel epoxide-containing low molecular weight compounds structurally resembling known antiangiogenic agents may also exhibit antiangiogenic activity. Cytochalasin E was found to be a potent and selective inhibitor of bovine capillary endothelial (BCE) ...

In the present study, xanthophyll composition of eight parasitic Cuscuta species under different light conditions was investigated. Neoxanthin was not detected in four of the eight species examined, while in others it occurred at the level of several percent of total xanthophylls. In C. gronovii and C. lupuliformis it was additionally found that the neoxanthin content was considerably stimulate...

Trichloroethylene (TCE), a structural analog of vinyl chloride, is known to induce hepatocellular carcinoma and other tumors in C57BL/6 X C3H/He F1 (hereafter known as B6C3F1) hybrid mice. TCE epoxide, a possible metabolite, is expected to be highly reactive toward cellular nucleophiles, e.g., proteins and nucleic acids. Hence, the microsomal metabolism of TCE and its covalent binding to micros...

4-Vinylcyclohexene (VCH) is present in gases discharged during synthetic rubber production. Chronic treatment of B6C3F1 mice and F-344 rats with VCH by gavage has been shown to induce ovarian tumors in mice but not in rats. Our objective was to understand the mechanism of the species difference in VCH-induced ovarian tumors. Since a critical step in the induction of ovarian tumors is destructio...

A highly purified and reconstituted hepatic microsomal monooxygenase system, completely free of epoxide hydrase and consisting of cytochrome P-448 from 3-methylcholanthrene-treated rats, NADPH-cytochrome c reductase, phosphatidylcholine, and NADPH, metabolizes benzo (a)pyrene to products highly mutagenic in strains TA 98 and TA 1538 of Salmonella typhimurium. The formation of mutagenic metaboli...