• Journal of Environmental Health Sciences
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• v.29 no.2
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• pp.23-28
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• 2003

To evaluate the effect of cyclohexane(CH) treatment on the liver cytochrome P-450 dependent aniline hydroxylase(CYPdAH) activity in alcohol-pretreated animals, CH(1.56 g/kg body weight) was intraperitoneally administered to Sprague-Dawley male rats, which had been drunk 15％ alcohol in distilled water for 1,3 and 6 weeks. CH was injected to rats 4 times every other day and the animals were sacrificed at 24 hours after injection of CH. In the alcohol-pretreated rats, liver injuries were not demonstrated on the basis of the liver weight per body weight, the levels of serum alanine aminotransferase and hepatic microsomal glucose-6-phosphatase activities. By the CH treatment, alcohol-pretreated animals showed the significantly increased activity of hepatic microsomal CYPdAH. Concomitantly $V_{max}$ value in CYPdAH was more increased, whereas $K_{M}$ value more decreased in alcohol-pretreated animals by the treatment of CH. In conclusion, the increasing cause of microsomal CYPdAH in CH-treated rats pretreated with alcohol may be due to induction of enzyme protein in rat liver.r.r.

• Biomedical Science Letters
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• v.9 no.2
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• pp.93-98
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• 2003

To investigate the cyclohexane and xylene mixture treatment on the liver damage, the rats were treated by the mixture of cyclohexane and xylene (CH＋X) and then, liver damage was demonstrated by liver function findings based on liver weight/body weight, serum level of alanine aminotransferase (ALT), xanthine oxidase (XO) and then compared with cyclohexane treated group (CH group) and xylene-treated group (X). The CH＋X group showed merely severer liver damge than CH or X group. On the other hand, CH＋X group showed lower activity of hepatic cytochrome P-450 dependent aniline hydroxylase (CYPdAH) than CH or X group, but no statical differences were demonstrated among three experimental groups. Especially the hepatic GSH content was merely declined than CH or X group and the activity of hepatic GST was higher in CH＋X group than CH or X group. In conclusion, cyclohexane and xylene mixture treated animals showed merely severer liver damage than cyclohexane or xylene treated group and such a fact may be caused by inhibition of cyclohexane or xylene metabolism and oxygen free radical.

• The Journal of the Korea Contents Association
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• v.21 no.4
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• pp.678-687
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• 2021

Styrene is a commercially important chemical used mainly in the production of raw materials and plastics. To determine the effect of styrene on hepatic activities of antioxidant enzymes, styrene was treated to Sprague-Dawley rats at 50 mg/kg, 200 mg/kg and 400 mg/kg (i.p) twice a day for 4 days. There were determined the significantly increased activities of serum AST (aspartate aminotransferase), ALT (alanine aminotransferse), and the increased content of MDA (malondialdehyde) at the dose of 400 mg/kg compared to the control. The hepatic activities of XO (xanthine oxidase) and CYPdAH (cytochrome P450 dependant aniline oxidase) in the dose of 400 mg/kg compared to the dose of 200 mg/kg were more increased, which means the excessive ROS (reactive oxygen species)s were produced during Phase I. In addition, significantly decreased were rates of the hepatic activities of GPx (glutathione peroxidase), CAT (catalase), SOD (superoxide dismutase) and GST (glutathione S-transferase) at the dose of 400 mg/kg compared to the control. And, the group at the dose of 400 mg/kg showed more significantly decreased GSH (glutathione) level than the group at the dose of 200 mg/kg. The decrease in GSH could ascribe to the toxic metabolites of styrene, such as styrene oxide. In conclusion, these results indicate that the excessive ROSs and the toxic metabolites of styrene may result in the hepatotoxicity, and be related to their imbalanced activities for antioxidant enzymes.

• Toxicological Research
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• v.19 no.2
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• pp.105-114
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• 2003

TO evaluate an effect of cyclohexane treatment on the degree of liver damage, rats were induced liver damage with 10 or 17 times $CCl_4$ injection (0.1 m1/100 g body wt., 50% $CCl_4$ dis-solved in olive oil) at intervals of every other day. Cyclohexane (1.56 g/kg body wt., i.p.) was administrated to the animals at 48 hours after the last pretreatment of $CCl_4$ . Rats were sacrificed at 4 hours after injection of cyclohexane. On the basis of histopathological findings, liver weight/body weight (LW/ BW, %), activities of serum alanine aminotransferase (ALT), xanthine oxidase (XO) and akaline phosphatase (ALP), and contents of liver protein and manlondialdehyde (MDA), $CCl_4$ -pretreatment induced liver damage. And $CCl_4$ 17 times treated group showed more severe liver damage than $CCl_4$ 10 times treated group. Administration of one dose of cyclohexane to $CCl_4$ 10 times treated animals resulted in the enhanced liver damage; liver necrosis with proliferation of fibroblast and bile duct abnormality, and increase in hepatic MDA content and the activities of serum ALP and ALT, But the enhanced liver damage was not found in $CCl_4$ 17 times treated animals. Serum cyclohexanone concentrations at 4 or 8 hours after injection of cyclohexane were higher in all liver damaged groups than normal group and were somewhat higher In $CCl_4$ 17 times treated animals than $CCl_4$ 10 times treated ones. Among the oxygen free radical metabolizing enzymes, hepatic cytochrome P45O dependent aniline hydroxylase (CYPdAH) activity in cyclohexane metabolizing enzyme system was meaningfully increased by the injection of cyclohexane to the liver damaged rats, with increased Vmax and high affinity to aniline. LW/BW (%) and activities of serum XO and ALT were more significantly increased in liver damaged groups than normal group by administration of cyclohexanone. In conclusion, it is assumed that an enhancement of liver damage by injection of one dose of cyclohexane to liver damaged animals might be caused by oxygen free radicals and cyclohexanone.

• Applied Microscopy
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• v.36 no.4
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• pp.291-297
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• 2006

To evaluate the effects of ingestion of alcoholic drinks on the toxicities of industrial compounds, cyclohexane (CH) was intraperitoneally administrated to rats (1.56g/kg body weight), which had been ingested 15% ethanol for up to 6 weeks,4 times by once a day and every other day. Following the last treatment of ethanol or CH, blood and liver tissues were collected after 4 hours prior to sacrifice of animals. By the injection of CH, liver weight (% of body weight) and xanthine oxidase activity in serum were increased, and glucose-6-phasphatase (G6P) activity in liver was decreased compared to them of control group. The activities of CH metabolizing enzymes, such as cytochrome P450 dependent aniline hydroxylase (CYPdAH) and alcohol dehydrogenase (ADH), were significantly increased by injection of CH, and those activities were the highest in CH-injected group after pretreated with alcohol. Ultrastructurally. both of alcohol treatment and CH injection induced transforming into the smooth-endoplasmic reticulum from rough-endoplasmic reticulum, the those rate was the highest in case of CH-injection after pretreated with alcohol. From these results, it is suggested that alcohol intake on a level without alcoholic degeneration of hepatocytes could enhance the CH metabolism of liver.