Acute effects of oral and intravenous ethanol on rat hepatic enzyme activities

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.

Effects of ethanol, fructose, and ethanol plus fructose infusions on plasma glucose concentration and glucose turnover in monkeys (Macaca fascicularis) as measured by [6-3H]glucose

Six adult, female, cynomolgus monkeys were fasted for 64 hr and then continuously infused with [6-3H]glucose to determine the rates of glucose turnover and clearance while they were also being infused with ethanol (110 mumol/min/kg), 1,3-butanediol (110 mumol/min/kg), fructose (30 mumol/min/kg) or ethanol plus fructose (110 and 30 mumol/min/kg) respectively. Both ethanol and 1,3-butanediol infusions decreased the glucose turnover rate (the steady-state input-output rate from the plasma glucose pool) and the plasma glucose concentration by halving the glucose production rate. In contrast, fructose infusions increased the glucose turnover rate and glucose concentration by increasing the glucose production rate by 20%. The plasma clearance rate of glucose was lowest when the animals were infused with ethanol plus fructose; this suggests that acetate from ethanol oxidation may have a glucose-sparing effect if normoglycemia is maintained.