Ethanol diversely alters palmitate, stearate, and oleate metabolism in the liver and pancreas of rats using the deuterium oxide single tracer.

OBJECTIVE: To determine tissue-specific effects of alcohol on fatty acid synthesis and distribution as related to functional changes in triglyceride transport and membrane formation.
METHODS: Tissue fatty acid profile and de novo lipogenesis were determined in adult male Wistar rats after 5 weeks of ethanol feeding using deuterated water and gas chromatography/mass spectrometry. Liver and pancreas fatty acid profiles and new synthesis fractions were compared with those from control rats on an isocaloric diet.
RESULTS: Fatty acid ratios in the liver indicated that there was a more than 2-fold accumulation of stearate to that of palmitate, with an apparent decrease in oleate content. On the other hand, in the pancreas, there was a 17% decrease in the stearate-to-palmitate ratio, whereas the oleate-to-palmitate ratio was increased by 30%. The fractions of deuterium-labeled palmitate and stearate were substantially reduced in the liver and pancreas of the alcohol-treated animals. Deuterium labeling of oleate was reduced in the liver but not in the pancreas, consistent with the oleate/stearate ratios in these tissues.
CONCLUSIONS: Long-term alcohol exposure results in opposite effects on the desaturase activity in the liver and pancreas, limiting fatty acid transport in the liver but promoting the exocrine function of the pancreas.