BACKGROUND Halothane is extensively (approximately 50%) metabolized in humans and undergoes both oxidative and reductive cytochrome P450-catalyzed hepatic biotransformation. Halothane is reduced under low oxygen tensions by CYP2A6 and CYP3A4 in human liver microsome to an unstable free radical, and then to the volatile metabolites chlorodifluoroethene (CDE) and chlorotrifluoroethane (CTE). The ...

To explore mechanisms of free radical reactions leading to intracellular lipid peroxidation in living systems, we developed a computational model of up to 109 simultaneous enzymatic and free radical reactions thought to be involved in the initiation, propagation, and termination of membrane lipid peroxidation. Rate constants for the various reactions were obtained from the published literature....

Rat liver microsomes have previously been utilized as a model biological system to study the activation of Adriamycin to the semiquinone free radical intermediate and the enhance ment by Adriamycin of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidation and oxygen consumption. Incubating rat liver microsomes with Adriamycin or other struc turally similar benzanthraquinone antic...

Nitric oxide ((*)NO) can protect cells against the detrimental effects of reactive oxygen species. Using low-density lipoprotein as well as model systems, it has been demonstrated that (*)NO can serve as a chain-breaking antioxidant to blunt lipid peroxidation. To test the hypothesis that (*)NO can serve as a chain-breaking antioxidant in cell membranes, we examined the effect of (*)NO on iron-...

Lipid peroxidation (LPO) in cellular membranes is associated with changes in physicochemical properties and impairment of protein functions located in membrane environment. Recent studies shows involvement of LPO in biological signaling and various diseases. Lipids are oxidized by three distinct mechanisms: enzymatic oxidation; non-enzymatic, free radical-mediated oxidation and non-enzymatic, n...