Dietary regulation of voluntary alcohol consumption in rats. Influence of a high protein diet and a methylene blue diet.
The importance of glucose homeostasis for high voluntary alcohol consumption was studied in alcohol-preferring (AA) and alcohol-avoiding (ANA) rats fed either a control diet, a protein-rich diet or a control diet supplemented with methylene blue. AA rats on the control diet were found to receive 13.6% of their daily energy intake from alcohol. On the high-protein or methylene blue diet, the alcohol consumption of the AA rats was respectively 40% and 48% higher than on the control diet. The voluntary alcohol consumption of ANA rats corresponded to 0.8-2.3% of their daily energy intake irrespective of diet. The protein diet increased the blood glucose concentration of AA rats by 20% but no increase was observed after the methylene blue diet. The diets had no effect on the blood glucose levels of ANA rats. In AA rats, the protein diet reduced the hepatic concentration of the three major glucogenic amino acids (serine, glycine, alanine) on average by 24%, suggesting an increased utilization for gluconeogenesis. No such reduction was observed in AA rats on the methylene blue diet or in ANA rats on any diet. The utilization of amino acids for maintenance of glucose balance in AA rats is further supported by the observed negative correlation between plasma concentration of urea, the end product of amino acid catabolism, and the sum of the concentrations of the three glucogenic amino acids in the liver, and by the positive correlation between plasma urea and blood glucose concentration. Furthermore, in AA rats, but not in ANA rats, the concentration of alanine, the main amino acid used in gluconeogenesis, correlated negatively with the amount of alcohol consumed. These findings indicate that the maintenance of glucose homeostatis is important for high voluntary alcohol consumption.
Department of Biochemistry, College of Veterinary Medicine, Helsinki, Finland.
A R
AR
Pösö
O A
OA
Forsander
D000428:Alcohol Drinking / Q000187:drug effects*; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose; D001835:Body Weight / Q000187:drug effects; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000494:pharmacology; D000431:Ethanol / Q000097:blood; D005260:Female; D005943:Gluconeogenesis / Q000187:drug effects; D006706:Homeostasis; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008751:Methylene Blue / Q000008:administration & dosage* / Q000494:pharmacology; D051381:Rats
D000596:Amino Acids; D001786:Blood Glucose; D004044:Dietary Proteins; D000431:Ethanol; D008751:Methylene Blue