Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We found that NADPH-dependent ubiquinone reductase (NADPH-UQ reductase) in rat liver cytosol reduces ubiquinone (UQ) to ubiquinol (UQH2) in lipid membranes and consequently inhibits lipid peroxidation [Takahashi T., et al., Biochem. J., 309, 883-890 (1995)]. Here we examined whether or not this UQH2-regenerating system functions as a cellular antioxidant defense in animals. Rats were given UQ-10 for 2 weeks, and were then exposed to carbon tetrachloride (CCl4). The UQ-10 supplement increased only in the NADPH-UQ reductase and the UQH2-10 pool of rat liver without any appreciable change in the levels of other antioxidant factors. On the other hand, CCl4 markedly increased plasma aspartate aminotransferase and alanine aminotransferase, liver weight and thiobarbituric acid reacting substances formation, which are indicators of CCl4-hepatitis, and it decreased the liver levels of L-ascorbic acid, reduced form of glutathione (GSH), alpha-tocopherol, NADPH-UQ reductase and glutathione S-transferase. However, all the above indicators of CCl4-induced hepatitis were significantly improved in rats given UQ-10. Furthermore, alpha-tocopherol, but neither L-ascorbic acid nor GSH, was significantly saved. UQ-10 supplement also was recovered glutathione S-transferase and NADPH-UQ reductase activities slightly. These results indicated that UQ-10 given to rats increased the cellular UQH2-10 pool and cytosolic NADPH-UQ reductase activity in their livers, resulting in the inhibition of lipid peroxidation in the biomembranes, and consequently protected the rats from the CCl4-hepatotoxicity.
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PMID:Cellular antioxidant defense by a ubiquinol-regenerating system coupled with cytosolic NADPH-dependent ubiquinone reductase: protective effect against carbon tetrachloride-induced hepatotoxicity in the rat. 887 5

To confirm whether or not cytosolic NADPH-UQ reductase is involved in the recycling of cellular ubiquinol (UQH2) consumed during lipid peroxidation, the effect of a UQ-10 supplement on the NADPH-UQ reductase and cellular defense against oxidative damage in rat livers was investigated. Supplements of UQ-10 for 14 days enhanced the levels of UQH2-10 and NADPH-UQ reductase in rat livers without any appreciable changes in other antioxidant contents and related enzyme activities. However, the injection of carbon tetrachloride (CCl4) into the rats induced lipid peroxidation and decreased the cellular UQH2-10 contents (and increased equivalent amounts of UQ-10), as well as decreasing the ascorbic acid, reduced glutathione (GSH) and alpha-tocopherol contents of the rat livers. Administration of the UQ-10 supplement prior to the CCl4 treatment spared alpha-tocopherol (but not GSH or ascorbic acid), inhibited lipid peroxidation, and thus improved CCl4-induced hepatitis. These findings support the notion that NADPH-UQ reductase in cytosol is the enzyme responsible for the regeneration of UQH2 from UQ formed by lipid peroxidation in cells.
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PMID:Cytosolic NADPH-UQ reductase-linked recycling of cellular ubiquinol: its protective effect against carbon tetrachloride hepatotoxicity in rat. 926 8

Oxidative stress is defined as a disturbance in the prooxidant-antioxidant balance in favor of the former and has been suggested to be a relevant factor in aging as well as in different pathological conditions, such as heart attack, diabetes, and cancer. Ubiquinol is very sensitive against oxygen radicals and gives ubiquinone as an oxidation product. Therefore, the ratio of ubiquinol to ubiquinone should be a good marker of oxidative stress because of its definition. A method for the simultaneous detection of ubiquinol-10 and ubiquinone-10 in human plasma is described. Heparinized human plasma was mixed with 5 volumes of methanol and 10 volumes of hexane. After vigorous shaking and centrifugation, the hexane phase (5 microliters) was injected immediately and directly on to reverse-phase HPLC equipped with an on-line reduction column and an electrochemical detector in order to avoid the oxidation of ubiquinol to ubiquinone. It was found that the ratio of ubiquinol-10 to ubiquinone-10 was about 95/5 in human plasma from healthy donors. A significant increase in the oxidized form (ubiquinone-10) content was observed in plasmas of patients with hepatitis, cirrhosis, and hepatoma when compared with normal subjects, suggesting increased oxidative stress in these patients.
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PMID:Plasma ratio of ubiquinol and ubiquinone as a marker of oxidative stress. 926 9

We have applied our method for the simultaneous detection of plasma ubiquinol-10 (reduced form) and ubiquinone-10 (oxidized form) (S. Yamashita and Y. Yamamoto, Anal. Biochem. 250, 66-73, 1997) to plasmas of normal subjects (n = 16) and patients with chronic active hepatitis (n = 28), liver cirrhosis (n = 16), and hepatocellular carcinoma (n = 20) to evaluate the pressure of oxidative stress in these patients. The average ubiquinone-10 percentages (+/- S.D.) in total ubiquinone-10 and ubiquinol-10 in the four groups were 6.4 +/- 3.3, 12.9 +/- 10.3, 10.6 +/- 6.8, and 18.9 +/- 11.1, respectively, indicating a significant increase in ubiquinone-10 percentage in patient groups in comparison to normal subjects. These results and a significant decrease in the plasma ascorbate level in patient groups indicate that oxidative stress is evident after the onset of hepatitis and the subsequent cirrhosis and liver cancer.
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PMID:Oxidative stress in patients with hepatitis, cirrhosis, and hepatoma evaluated by plasma antioxidants. 963 73

Chronic infection of hepatitis virus B (HBV) has been proven to be one of the most important risk factors of hepatocellular carcinoma (HCC). HBx has been shown to function in the viral life cycle and the development of HCC. Recently, we have reported that HBx transgenic mice (p21-HBx), generated by gene knockin, develop HCC at the age of 18 months. To further study the function of HBx during the development of HCC in vivo, we performed proteomic analysis of the transgenic and wild-type control mice. The combination of 2-DE and MALDI-TOF MS revealed that proteasome subunits (PSMA6, PSMB4, PSMC2 and PSMD12) were up-regulated in tumor tissues of the p21-HBx transgenic mice. Cathepsin B, ubiquinol-cytochrome C reductase core protein 1 and an ATP-dependent caseinolytic protease, which were involved in the cellular proteolytic process, were also found increased in tumors. The results were confirmed in tumors of transgenic mice and HCCs of human using RT-PCR. All these results suggested that the strengthened ubiquitin-proteasome and lysosomal pathway might contribute to the development of HBx-related HCC.
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PMID:The up-regulation of proteasome subunits and lysosomal proteases in hepatocellular carcinomas of the HBx gene knockin transgenic mice. 1631 74