Effect ofIn Vivo andIn Vitro treatment with arsenite on rat hepatic mitochondrial and microsomal enzymes

Abstract

The effects of arsenite on activities of several enzymes including mitochondrial pyruvate dehydrogenase (PDH) and succinate dehydrogenase (SDH), microsomal cytochrome P450 and b5, NAD(P)H cytochrome C reductase and glutathione S-transferase were studied. The effects of arsenite on the mitochondrial membrane lipid peroxidation (LPO), the content of hepatic cytosol reduced glutathione and the activity of glutathione peroxidase was also investigated in rats. The results indicated that the activities of mitochondrial PDH and SDH were inhibited to 59 % and 57 % of the control activities respectively after arsenite was administered by intraperitoneal injection (i. p.) for 7 consecutive days at a dose of 20 mg/kg. Administration of arsenite led to a potential decrease of GSH content. The increase in lipid peroxidation of liver mitochondrial membrane prepared from rats treated with arsenite was also observed (P<0. 05). Arsenite did not appear to affect the liver cytosolic glutathione peroxidase and microsomal enzyme activitiesin vivo. Inin vitro test, liver mitochondria and cytosol were treated with arsenite, which led to a decreased SDH activity and GSH content and increase of mitochondrial LPO in a dose-dependent pattern that was similar to the results obtained inin vitro experiments. Selenite played a significant antagonistic role in effects of arsenite eitherin vivo orin vitro on the activities of mitochondrial PDH and SDH, and the content of mitochondrial LPO and cytosolic GSH. This results suggested that the toxic effects of arsenite on rat were associated with increased levels of LPO and the injured SH group in body caused by arsenite.

Keywords

arsenite / mitochondria / microsome / glutathione / lipid peroxidation / glutathione peroxidase

References

[1] YamahakaK, HasegawaA, SawamuraR, et al. . DNA strand breaks in mammalian tissues induced by methylarsenics. Biochem Biophy Res Commun, 1991, 21: 413-413

[2] RemmerH, GreimH, SchenkmanJ B, et al. . Methods for the evaluation of hepatic microsomal mixed function oxidase levels and cytochrome P450. Methods Enzymol, 1967, 10: 703-703

[3] LowryO H, RosebroughW J, FarrA L, et al. . Protein measurement with the Folin phenol reagent. J Biol Chem, 1951, 193: 265-265

[4] FloraH, RettitM, LestJ. Pyruvate dehydrogenase complex from bovinekidney and heart. Methods Enzymol, 1979, 95: 351-351

[5] BrainA, ChreyA K. Mammalian succinate dehydrogenase. Methods Enzymol, 1979, 53: 466-466

[6] OmuraT, SatoR. The carbon monoxide-binding pigment of liver microsomes. I. Evidence for its hemoprotein nature. J Biol Chem, 1964, 239: 2-370

[7] MastersB S S, WilliamsC H, KaminH. The preparation and properties of microsomal TPNH-cytochrome C reductase from dog liver. Methods Enzymol, 1967, 10: 565-565

[8] WarholmM, GuthenbergC, Von BahnC, et al. . Glutathione transferase from human liver. Methods Enzymol, 1985, 113: 499-499

[9] LawrenceR A, BurkR F. Glutathione peroxidase activity in selenium-deficient rat liver. Biochem Biophys Res Commun, 1976, 71: 952-952

[10] HissinP J, HilfR. A fluorometric method for determination of oxidased and reduced glutathione in tissues. Anal Biochem, 1976, 74: 214-214

[11] OhkawaH, OhishiN, VagiK. Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction. Anal Biochem, 1979, 95: 351-351

[12] HassinenJ, HallmanM. Comparison of the effects of disulfirum and dimercaptopropanol arsenite on mitochondrial structure and function. Biochem Pharmacol, 1967, 16: 2155-2155

[13] SuttorpN, ToepferW, RokaL. Antioxidant defense mechanisms of endotheliol cells: glutathione redox cycle versus catalase. Am J Physiol, 1986, 251: 1671-1671

[14] ReterL, KeelingL. Relevance of NADPH depletion and mixed disulfide formation in rat lung to the mechanism of cell damage folowing paraquat administration. Biochem Pharmacol, 1982, 31(203243-3243

[15] PorterT D, CoonM J. Cytochrome P450: Multiplicity of isoforms, substrates, and catalytic and regulatory mechanisms. J Biol Chem, 1991, 266: 13469-13469