Mixed-function oxidase induction

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. 

Mixed-function Oxidase Induction.-- Indirect evidence of environmental induction of detoxifying enzymes in the R fish has been observed as an increase in the acute toxicity of parathion and a simultaneous decrease in NADPH-dependent parathion... 

Butler, W.H. (1996). A review of the hepatic tumours related to mixed function oxidase induction in the mouse. Toxic ot. Pat hoi. 24, 484 492... 

Perry, W. and Jenkins, M. V. (1986) Hepatic mixed function oxidase induction during rifampicin/isoniazid therapy in Indian vegetarians. Int. J. Clin. Pharmacol. Ther. Toxicol. 24, 344—348. 

Tyagi SR, Sing Y, Srivastava PK, et al. 1984. Induction of hepatic mixed function oxidase system by endosulfan in rats. Bull Environ Contam Toxicol 32 550-556. 

Rifkind, A.B., A. Firpo, Jr., and D.R. Alonso. 1984. Coordinate induction of cytochrome P-448 mediated mixed function oxidases and histopathologic changes produced acutely in chick embryo liver by polychlorinated biphenyl congeners. Toxicol. Appl. Pharmacol. 72 343-354. 

Baker RC, Coons LB, Mailman RB, et al. 1972. Induction of hepatic mixed function oxidases by the insecticide mirex. Environ Res 5 418-424. 

Fabacher DL, Hodgson E. 1976. Induction of hepatic mixed-function oxidase enzymes in adult and neonatal mice by Kepone and mirex. Toxicol Appl Pharmacol 38 71-77. 

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. 

Mehendale HM, Takanaka A, Desaiah D, et al. 1977a. Kepone induction of hepatic mixed function oxidases. Life Sci 20(6) 991-997. 

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. 

Chambers, J.E. Induction of mixed-function oxidase activity... 

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. 

Addison, R.F., Zinck, M.E. and Willis, D.E. Mixed function oxidase enzymes in trout (Salvelinus fontinalis) liver Absence of induction following feeding of p,p -DDT or p,p -DDE. Comp. Biochem. Physiol. (1977) 57C 39-43. 

Kraft bleach mill effluent produced by oxygen delignification or 100% chlorine dioxide Ereshwater fish Induction of mixed function oxidase (MEO) enzymes following exposure to 4% and 12% effluent in artificial streams Bankey et al., 1995 [28]... 

Although first reported with the cytochrome(s) P-450 mixed function oxidases, it is now known that a number of the enzymes involved in the metabolism of foreign compounds are inducible. Thus, as well as the CYPs, NADPH cytochrome P-450 reductase, cytochrome b5, glucuronosyl transferases, epoxide hydrolases, and GSTs are also induced to various degrees. However, this discussion concentrates on the induction of the CYPs with mention of other enzymes where appropriate. 

Muir, D.C.G., Yarechewski, A.L., Metner, D.A., Lockhart, W.L., Webster, G.R.B., Friesen, K.J. (1990) Dietary accumulation and sustained hepatic mixed function oxidase enzyme induction by 2,3,4,7,8-pentachlorodibenzofuran in rainbow trout. Environ. Toxicol. Chem. 9, 1463-1472. 

Brownlee LJ, Evans CH, Hollebone BR. 1986. The relative induction of mixed-function oxidase specific activity to carbon-hydrogen and carbon-carbon 1 bond strengths in polychlorinated derivatives of dibenzo-p-dioxin. J Appl Toxicol 6 67-72. 

There are several known effects of BHA treatment which have been proposed to reduce the levels of reactive metabolites of BP which bind to DNA. It has been demonstrated that BHA feeding alters the microsomal mixed-function oxidase system in mice and rats (7,17-19). Several studies suggest that BHA treatment does not decrease the amounts of BP-7, 8-diol formed (7,20,21) whereas there is some indirect evidence that BHA treatment alters the metabolism of BP-7,8-diol (3,20) An induction by BHA of an lsozyme(s) of cytochrome P-450, which has kinetics of metabolism of BP-7,8-diol different than that of the constitutive isozyme(s), could account for the BHA-induced shifts in the dose-response curve for BPDEI-DNA adduct levels (15). 

R.C. Baker, L.D. Cooris, R.B. Mailman, and E. Hodgson, Induction of hepatic mixed function oxidase by insecticide mirex. Environ. Res. 5 418, 1972. 

Clofibrate at a concentration of 0.5 mmol in culture medium maintained the cytochrome P-450 content of rat hepatocytes for up to 96 h. This effect was associated with a marked induction of lauric acid hydroxylation whereas little effect was observed on the metabolism of three other cytochrome p450 dependent mixed function oxidase substrates. 

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