Liver alcohol oxidizing systems and gluconeogenic enzyme activities after long term ethanol application in cold exposed guinea pigs.
The effects of 4-weeks ethanol application (20% ethanol, w/w, 2 g X kg-1 on the alcohol oxidizing systems and gluconeogenic enzyme activities of the liver in guinea pigs kept in the cold (+4 degrees C) and at room temperature (+20 degrees C) were studied. The controls were guinea pigs reared at room temperature or in a cold environment without ethanol. The study showed a significant increase (1.5-fold) in liver microsomal cytochrome P-450 after chronic ethanol treatment at room temperature, but not in a cold environment. Microsomal NADPH oxidase activity did not significantly change in any group. Ethanol treatment in a cold environment resulted in a significant increase in liver mitochondrial cytochromes, aa3 and c+c1, and at room temperature in cyt aa3. The activities of total liver homogenate alcohol dehydrogenase or catalase did not change after chronic ethanol treatment. The activity of liver fructose-1.6-diphosphatase showed a significant ethanol induced decrease at room temperature, an effect not observed in the cold environment. Ethanol increased glucose-6-phosphatase activity in the cold, but not at room temperature. In conclusion, the stimulation of liver mitochondrial cytochromes and microsomal cyt P-450 as a consequence of chronic ethanol treatment indicated an increased oxidation capacity for ethanol. The stimulation of glucose-6-phosphatase in a cold environment might be responsible for increasing glucose for heat production after chronic ethanol treatment in cold adapted animals.
D000429:Alcohol Oxidoreductases / Q000378:metabolism; D000818:Animals; D003080:Cold Temperature; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism* / Q000494:pharmacology; D006597:Fructose-Bisphosphatase / Q000378:metabolism; D005943:Gluconeogenesis; D005952:Glucose-6-Phosphatase / Q000378:metabolism; D006168:Guinea Pigs; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D010084:Oxidation-Reduction; D013997:Time Factors
D000431:Ethanol; D003577:Cytochrome P-450 Enzyme System; D000429:Alcohol Oxidoreductases; D003576:Electron Transport Complex IV; D006597:Fructose-Bisphosphatase; D005952:Glucose-6-Phosphatase