Oleoylethanolamide (OEA) is an endogenous lipid mediator that inhibits feeding in
rats and mice by activating the nuclear receptor peroxisome proliferator-activated
receptor-alpha (PPAR-alpha). In rodents, intestinal OEA levels increase about threefold
upon refeeding, a response that may contribute to the induction of between-meal satiety.
Here, we examined whether feeding-induced OEA mobilization also occurs in Burmese
pythons (Python molurus), a species of ambush-hunting snakes that consume huge meals
after months of fasting and undergo massive feeding-dependent changes in gastrointestinal
hormonal release and gut morphology. Using liquid chromatography/mass spectrometry
(LC/MS), we measured OEA levels in the gastrointestinal tract of fasted (28 days)
and fed (48 h after feeding) pythons. We observed a nearly 300-fold increase in OEA
levels in the small intestine of fed compared with fasted animals (322 +/- 121 vs.
1 +/- 1 pmol/mg protein, n = 3-4). In situ OEA biosynthesis was suggested by the concomitant
increase of N-acyl phosphatidylethanolamine species that serve as potential biosynthetic
precursors for OEA. Furthermore, we observed a concomitant increase in saturated,
mono- and diunsaturated, but not polyunsaturated fatty-acid ethanolamides (FAE) in
the small intestine of fed pythons. The identification of OEA and other FAEs in the
gastrointestinal tract of Python molurus suggests that this class of lipid messengers
may be widespread among vertebrate groups and may represent an evolutionarily ancient
means of regulating energy intake.