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    Effects of nonyphenol exposure during pregnant and lactation period on expressions of CYP2E1 mRNA and protein of hepatic tissues in offspring rats.
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    Enzymes in the histologically normal liver of hosts of mammary carcinomas were examined for their responsiveness to endocrine and dietary modulations. Treatments with the developmental stimuli of alanine aminotransferase (glucocorticoids) and of pyruvate kinase (thyroid hormone) which had no effect in control adult rats raised the levels of these enzymes in the tumor-bearing rats. The latter also showed a greater percentage of increase in malic enzyme upon thyroid hormone administration than did control animals. The tumor-induced increase in hexokinase remained unaltered by the various dietary treatments; enzymes at subnormal levels were raised (glucokinase, malic enzymes, and pyruvate kinase) or further decreased (alanine aminotransferase and ornithine aminotransferase) by excessive carbohydrate intake in immature and adult experimental rats. The normal upsurge of glucokinase and malic enzyme upon weaning to the standard solid diet (from the relatively low-carbohydrate-containing milk) was prevented by cancerous growth in the organism. Similarly, the standard diet, which reversed within 2 days the partial loss of these enzymes in normal adult rats fasted for 48 hr, had no restorative effect on the essentially complete loss of the glucokinase and the very low malic enzyme activity in the fasted tumor bearers. The results suggest that failure in the dietary adaptations of hepatic enzymes as well as diminutions of their basal levels contributes to the clinically observed abnormalities in the glucose metabolism of cancer subjects.
    Glucokinase
    Malic enzyme
    Hexokinase
    Citations (3)
    Abstract Choline is an essential nutrient that seems to be involved in a wide variety of metabolic reactions and functions in both humans and rodents. Various pathophysiological states have been linked to choline deprivation (CD). The aim of the present study was to determine the effect of CD upon biochemical, histological and metabolic alterations induced by drugs that affect hepatic functional integrity and various drug metabolizing systems via distinct mechanisms. For this purpose, paracetamol (ACET) or phenobarbital (PB) were administered to male Wistar rats that were fed with standard rodent chow (normally fed, NF) or underwent dietary CD. The administration of ACET increased the serum aspartate aminotransferase levels in NF rats, while CD restricted this increase. On the other hand, ACET suppressed alkaline phosphatase levels only in CD rats. Moreover, CD prevented the PB‐induced increase of the mitotic activity of hepatocytes. The administration of ACET down‐regulated CYP1A2 and CYP2B1 expression in CD rats, while up‐regulating them in NF rats. The administration of PB suppressed CYP1A2 apoprotein levels in CD rats, whereas the drug had no effect on NF rats. The PB‐induced up‐regulation of CYP2B, CYP2E1 and CYP1A1 isozymes was markedly higher in CD than in NF rats. In addition, PB increased glutathione‐ S ‐transferase activity only in CD rats. Hepatic glutathione content (GSH) was suppressed by ACET in NF rats, whereas the drug increased GSH in CD rats. Our data suggest that CD has a significant impact on the hepatic metabolic functions, and in particular on those related to drug metabolism. Thus, CD may modify drug effectiveness and toxicity, as well as drug–drug interactions, particularly those related to ACET and PB. Copyright © 2008 John Wiley & Sons, Ltd.
    Phenobarbital
    Citations (9)
    The aim of the current study was to examine the effects of chronic consumption of soft drinks (SDs) on hepatic oxidative stress and cytochrome P450 enzymes (CYPs) expression in the livers of Wistar rats. For 3 consecutive months, the rats had free access to three different soft drinks, Coca‑Cola, Pepsi‑Cola and 7‑UP. The rats were subsequently compared with control group rats that had consumed water. Blood and hepatic tissue samples were assayed for the changes in antioxidants, liver function biomarkers and hepatic gene expression for different isoforms of hepatic CYP. The results indicated that SD consumption (SDC) decreased serum antioxidant levels and increased malondialdehyde secretion, and increased liver biomarkers (glutamate pyruvate transaminase and glutamate oxaloacetate). SD induced alterations in mRNA expression of hepatic antioxidants and cytochrome isoforms. The expression of peroxidase, catalase, CYP1A2, CYP3A2 and CYP2C11 in the liver were upregulated following SDC. By contrast, CYP2B1 was downregulated after 3 months of SDC in liver tissue samples. Thus, the present findings indicate that SDs induced oxidative stress in the liver of Wistar rats and for the first time, to the best of our knowledge, indicate that SDC disrupts hepatic CYP enzymes that may affect drug metabolism. Therefore, drug‑dosing programs should be carefully designed to take these novel findings into consideration for the treatment of diseases.
    Malondialdehyde
    Liver function
    Citations (8)
    The aim was to establish the morphofunctional changes of liver in the experimental cirrhosis. Materials and methods: The research was conducted on 24 white male Wistar rats. Experimental cirrhosis of the liver was simulated by oral administration of CCl4 2 g/kg 2 times weekly for three months. From the selected fragments of the liver, histological specimens were done according to the conventional method and examined by light microscopy. The activity of the enzymes of cytolysis and cholestasis (ALT, AST, alkaline phosphatase), the content of components of bile (cholesterol, bilirubin and bile acids) were determined in the serum. In the blood and liver were determined the content of the final products of metabolism of nitric oxide: NO2 - and NO3 -; in the blood – the content of ceruloplasmin, lactate, pyruvate, middle molecular-weight protein MWP1 and MWP2. In the liver – the activity of succinate dehydrogenase (SDG) and cytochrome oxidase (CHO), N-demethylase and p-hydroxylase microsomal activity. The state of the system of prooxidants-antioxidants was judged by the content in the liver of thiobarbituric acid reactive substance (TBARS), lipid hydroperoxide (LHP), concentration of sulfhydril group (GSH), catalase activities (CAT), superoxide dismutase (SOD). The content of endothelial (eNOS) and inducible (iNOS) NO synthases, the concentration of pro-inflammatory cytokines IL-1β, IL-6 and TNF-α were determined by the enzyme immunoassay. Results: Cirrhosis of the liver, which is morphologically confirmed by the presence of prominent sclerosis in the periportal zones and the formation of umbel, is accompanied by the development of cytolysis and cholestasis processes with an increase in the content of components of bile in the blood (cholesterol, bilirubin and bile acids). An increase in the content of lipoperoxidation products and disturbance of the state of the enzymatic and non-enzymatic units of the antioxidant system, decrease in the activity of mitochondrial (succinate dehydrogenase and cytochrome oxidase) enzymes have been established. The activity of the detoxification processes decreases, namely the inhibition of N-demethylase and p-hydroxylase activity of the liver microsomes, so the manifestations of endotoxicosis increase. This is accompanied with decreased content of endothelial and an increased content inducible NO synthase, a concentration of a stable metabolite of nitric oxide nitrite anion in the blood increase and a decrease in the liver. Сonclusions: Experimental CCl4 cirrhosis is characterized morphologically by sclerosis in the periportal zones and the formation of umbao. The metabolic and functional cirrhoticliver is characterized by cytolysis and cholestasis activation, inhibition of detoxication, prooxidant-antooxidant, including nitrooxidative, disbalance.
    TBARS
    Liver function
    Citations (10)
    Compared with controls, patients with alcoholic fatty liver showed a significant increase of gamma-glutamyltransferase activity both in the liver and serum, whereas alkaline phosphatase activity was raised only in the liver but not in the serum. The activities of other enzymes such as aspartate aminotransferase, alanine aminotransferase and glutamate dehydrogenase remained virtually unchanged in the liver of patients with alcoholic fatty liver but were strikingly enhanced in the serum. The hepatic and serum alterations of enzymic activities observed in patients with alcoholic fatty liver could be reproduced in the rat model of alcoholic fatty liver only for gamma-glutamyltransferase but not for the other enzymes tested, substantiating evidence that the animal model may serve as an appropriate tool for studying interactions between alcohol and gamma-glutamyltransferase. The present experiments also indicate that the primary cause for increased serum gamma-glutamyltransferase activities associated with prolonged alcohol consumption is hepatic enzyme induction rather than liver cell injury.
    Gamma-glutamyltransferase
    Alcoholic fatty liver
    Liver cell
    Citations (59)
    The interaction of HCH (50 mg/kg) and dietary protein levels on microsomal drug metabolizing enzymes system and liver lipids were studied in the rats for 90 days. The results indicated that rats fed a lower protein diet and HCH has a higher rate of mortality, lower rate of growth and an increased liver weight. A significant induction in the hepatic microsomal aminopyrine‐N‐demethylase, p‐nitroanisole‐O‐dealkylase, benzo(a)pyrene hydroxylase and glutathione‐S‐transferase activity was observed in pesticide treated animals as compared to control animals. The pathological changes observed in liver of HCH treated animals consisted mainly of necrosis and fatty degeneration of hepatocytes. HCH also induced the significant accumulation of cholesterol, triglycerides, phospholipid and total lipid in liver in low protein diet animals. Protein accelerates the metabolism of HCH, resulting in a decrease of HCH concentration with the increase of dietary protein level. A close correlation existed between lipid accumulation, induction of drug metabolizing enzyme system and deposition of HCH in liver.
    Citations (0)
    Abstract This work investigated the in vivo and in vitro effects of HgCl 2 and ZnCl 2 on metabolic enzymes from tissues of young rats to verify whether the physiological and biochemical alterations induced by mercury and prevented by zinc are related to hepatic and renal glucose metabolism. Wistar rats received (subcutaneous) saline or ZnCl 2 (27 mg/kg/day) from 3 to 7 days old and saline or HgCl 2 (5.0 mg/kg/day) from 8 to 12 days old. Mercury exposure increased the hepatic alanine aminotransferase (∼6‐fold) and glucose 6‐phosphatase (75%) activity; zinc pre‐exposure prevented totally and partially these mercury alterations respectively. In vitro , HgCl 2 inhibited the serum (22%, 10 μM) and liver (54%, 100 μM) alanine aminotransferase, serum (53%) and liver (64%) lactate dehydrogenase (10 μM), and liver (53%) and kidney (41%) glucose 6‐phosphatase (100 μM) from 10‐ to 13‐day‐old rats. The results show that mercury induces distinct alterations in these enzymes when tested in vivo or in vitro as well as when different sources were used. The increase of both hepatic alanine aminotransferase and glucose 6‐phosphatase activity suggests that the mercury‐exposed rats have increased gluconeogenic activity in the liver. Zinc prevents the in vivo effects on metabolic changes induced by mercury.
    Mercury
    Citations (15)
    Blood alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities are widely used as sensitive markers of liver toxicity. However, these activities are also recognized to be altered by hormonal and nutritional modifications. We investigated the relationships between the activity and gene expression of the hepatic transaminases and the state of hepatic amino acid/glucose/fatty acid metabolism in the ad libitum fed (ALF) and spaced-fed (SF) rats. Acceleration of hepatic gluconeogenesis and fatty acid oxidation was noted in the SF rats. Expression of hepatic clock gene was also altered in the SF rats. Hepatic transaminase activities in the SF rats were higher than those in the ALF rats. These alterations were due to increases in the synthesis of hepatic ALT and AST proteins. In conclusion, the increased transaminase protein synthesis in the liver of the SF rats was considered to be related to the acceleration of hepatic gluconeogenesis under the conditions of spaced feeding.
    Gluconeogenesis
    Transaminase
    Aspartate transaminase
    Fatty acid synthesis
    Citations (17)