Microsomal mixed function

Lipid-soluble xenobiotics are commonly biotra ns formed by oxidation in the drug-metabolizing microsomal system (DMMS). For each description below, choose the component of the microsomal mixed-function oxidase system with which it is most closely associated ... 

Diarrhea, reduced food and water consumption, body weight loss, decreased blood glucose levels, and disrupted hepatic microsomal mixed function oxidases in mice receiving 10 mg/kg body weight daily (Fujimori et al. 1983). 

Shull, L.R., B.A. Olson, B.J. Hughes, R.M. McKenzie, and J.H. Kinzell. 1986. Effect of pentachlorophenol on microsomal mixed-function oxidases in cattle. Pest. Biochem. Physiol. 25 31-39. 

Arinc, E. and A. Sen. 1994. Effects of in vivo benzo[a]pyrene treatment on liver microsomal mixed-function oxidase activities of gilthead seabream (Sparus aurata). Comp. Biochem. Physiol. 107C 405-414. 

Fabacher, D.L. and P.C. Baumann. 1985. Enlarged livers and hepatic microsomal mixed-function oxidase components in tumor-bearing brown bullheads from a chemically contaminated river. Environ. Toxicol. Chem. 4 703-710. 

Liver necrosis is another concern following hexachloroethane exposure. Hexachloroethane is metabolized in the centrilobular area of the liver by way of the microsomal mixed function oxidase system. The relatively nonpolar pentachloroethyl free radical is an intermediate in this pathway. The reaction of the free radical with unsaturated lipids in the cellular or organelle membranes could contribute to hepatocyte damage and necrosis. 

Knights KM, Gourlay GK, Cousins MJ. Changes in rat hepatic microsomal mixed function oxidase activity following exposure to halothane under various oxygen concentrations. Biochem Pharmacol 1987 36(6) 897-906. 

Freudenthal, R., Leber, P., Emmerling, D., Kerchner, G. and Campbell, D. (1976). Characterization of the hepatic microsomal mixed-function oxidase system in miniature pigs. Drug Metab. Dispos. 4 25-27. 

Estabrook, R.W., Hildebrandt, A.G., Baron, J., Netter, K.J. and Leibman, K. (1971) A new spectral intermediate associated with cytochrome P-450 function in liver microsomes. Biochemical and Biophysical Research Communications, 42 (1), 132-139. Pompon, D. and Coon, M.J. (1984) On the mechanism of action of cytochrome P-450. Oxidation and reduction of the ferrous dioxygen complex of liver microsomal cytochrome P-450 by cytochrome b5. Journal of Biological Chemistry, 259 (24), 15377-15385. Hildebrandt, A. and Estabrook, R.W. (1971) Evidence for the participation of cytochrome b 5 in hepatic microsomal mixed-function oxidation reactions. Archives of Biochemistry and Biophysics, 143 (1), 66-79. 

Madhukar BV, Matsumura F. 1979. Comparison of induction patterns of rat hepatic microsomal mixed-function oxidases by pesticides and related chemicals. Pestic Biochem Physiol 11(1-3)301-308. 

Peppriell J. 1981. The induction of hepatic microsomal mixed-function oxidase activities in the mouse by mirex, 3,4,5,3 ,4 ,5 -hexachlorobiphenyl, and equimolar dosages of both. Environ Res 26 402-408. 

Hildebrandt A., Estabrook RW. 1971. Evidence for the participation of cytochrome b5 in hepatic microsomal mixed-function oxidase reactions. Arch Biochem Biophys 143 66-79. 

Stevens JT, Greene FE, Stitzel RE, et al. 1973. Effects of anticholinesterase insecticides on mouse and rat liver microsomal mixed function oxidase. In Deichmann W.B., Ed. Pesticides and the environment A continuing controversy. Proceedings of the 8th Inter-American Conference on Toxicology and Occupational Medicine, University of Miami School of Medicine, 489-501. 

Quantitation and Identification of 11>C-labeled Metabolites. In the iji vitro microsomal mixed-function oxidase system,... 

In water containing fish, 4-keto molinate constituted 36.8% of all organosoluble metabolites 4 days after molinate addition. However, in the in vitro microsomal mixed-function oxidase system 4-hydroxy molinate was a principal metabolite (14.3%) and 4-keto molinate represented only 0.16% of the total metabolites. Keto-HMI (2.71%) also constituted a substantial proportion of the identified metabolites. 

The biotransformation systems involved in insecticide metabolism have been studied in the R and S populations to determine any differences which might be potential contributory factors to or results of insecticide resistance. In addition, the possibility of mixed-function oxidase induction has been investigated. Specifically, the studies have encompassed a seasonal study of microsomal mixed-function oxidase (mfo) components, and studies of aldrin, dieldrin and DDT metabolism. 

Hepatic microsomal mixed-function oxidase activity of several marine species from coastal Maine. Drug Metab. Dispos. 

Bend, J.R., Pohl, R.J., Davidson, N.P. and Fouts, J.R. Response of hepatic and renal microsomal mixed-function oxidases in the little skate, Ra.ja erinacea, to pretreatment with 3-methyl-cholanthrene or TCDD (2,3,7,8-tetrachlorodibenzo- -dioxin). Bull. Mt, Desert Is. Biol. 

Burns, K.A. Microsomal mixed function oxidases in an estuarine fish, funduLus heteroclitus, and their induction as a result of environmental contamination. Comp. Biochem. Physiol. (1976) 53B, l l 3- + +6. 

Ahokas, J.T. Metabolism of 2,5-diphenyloxazole (PP0) by trout liver microsomal mixed function monooxygenase. Res. Commun. Chem. Pathol. Pharmacol. (1976) 13, 1+39-1+1+7. 

Microsomal Mixed-Function Oxidation in Untreated and Polycyclic Aromatic Hydrocarbon-Treated Marine Fish... 

Pohl, R. J., Bend, J. R., Guarino, A. M., and Fouts, J. R. Hepatic microsomal mixed-function oxidase activity of several marine species from coastal Maine. Drug Metab. Dispos. (1974) 2 545-555. 

Bend, J. R., Bogar, A., and Foureman, G. L. Partially induced hepatic microsomal mixed-function oxidase systems in individual winter flounder, Pseudoplenroneates ameriaanus, from coastal Maine. Bull. Mt. Desert Island Biol. Lab. (1977) 17 47-49. 

Bend, J.R., Ball, L.M., Elmamlouk, T.H., James, M.O. and Philpot, R.M. Microsomal mixed-function oxidation in untreated and polycyclic aromatic hydrocarbon-treated marine fish. This volume. 

Shih TW, Hill DL. 1981. Metabolic activation of 1,2-dibromoethane by glutathione transferase and by microsomal mixed function oxidase Further evidence for formation of two reactive metabolites. Res Common Chem Pathol Pharmacol 33 449-461. 

In addition, oral administration of 1- C-2-hexanone to humans or rats results in the appearance of CO in the expired breath (DiVincenzo et al. 1977, 1978), indicating oxidation/cleavage of the alpha carbon. Administration of SKF525A (a mixed function oxidase inhibitor) to rats before oral administration of 2-hexanone resulted in a marked decrease in the excretion of respiratory CO for the first 4 hours after administration, followed by a marked increase at 4-8 and 12-24 hours. This suggests that this oxidative step is mediated by a microsomal mixed function oxidase system (DiVincenzo etal. 1977). 

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