Effect of acute and chronic ethanol administration on the content of coenzymes linked to energy transfer in the liver of rats fed standard or low-protein diet.

1) In rats fed a standard diet or a protein restricted diet the effect of acute and chronic ethanol administration on liver content of adenine nucleotides was studied. In the long-term experiments the total liver content of NAD and NADP was additionally determined. 2) a single oral ethanol load does not significantly influence the total adenine nucleotide content. Liver AMP content increases immediately following ethanol ingestion about 2-fold and remains elevated for 12 hours. ATP content and ATP/ADP ratio are significantly reduced within 30 minutes after ethanol administration. Both return to initial values after 2 hours adn decrease again thereafter. 3) The increase in the AMP content is dose dependent, i.e. it is more pronounced after small doses of ethanol and is not observed when blood ethanol concentrations are very high. The elevation of the AMP levels during ethanol oxidation is interpreted as a consequence of increased ATP consumption and of inhibition of citric acid cycle. 4) In animals fed nearly protein-free diet, total adenine nucleotide content and ATP content are distinctly reduced. An increase in AMP concentration is not observed in these rats where ethanol oxidation is markedly inhibited. 5) Chronic ethanol application does neither in rats kept on a standard diet nor in those fed a protein restricted regimen affect the liver content of total adenine nucleotides or ATP. Similarly the total content of NAD and NADP shows no major changes. 6) It is concluded that the relatively small alterations in total liver adenine nucleotide content and in the different adenine nucleotide fractions are not important for ethanol-induced fat accumulation or other disturbances in the liver.