Related Experiment Video
Updated: Jun 22, 2026

Assessment of the Metabolic Effects of Isocaloric 2:1 Intermittent Fasting in Mice
Published on: November 27, 2019
Basal and fasting/refeeding-regulated tissue levels of endogenous PPAR-alpha ligands in Zucker rats
Angelo A Izzo1, Fabiana Piscitelli, Raffaele Capasso
1Department of Experimental Pharmacology, University of Naples Federico II, Naples, Italy.
Abstract:
N-oleoylethanolamine (OEA) and N-palmitoylethanolamine (PEA) are endogenous lipids that activate peroxisome proliferator-activated receptor-alpha with high and intermediate potency, and exert anorectic and anti-inflammatory actions in rats, respectively. We investigated OEA and PEA tissue level regulation by the nutritional status in lean and obese rats. OEA and PEA levels in the brainstem, duodenum, liver, pancreas, and visceral (VAT) or subcutaneous (SAT) adipose tissues of 7-week-old wild-type (WT) and Zucker rats, fed ad libitum or following overnight food deprivation, with and without refeeding, were measured by liquid chromatography-mass spectrometry. In WT rats, duodenal OEA, but not PEA, levels were reduced by food deprivation and restored by refeeding, whereas the opposite was observed for OEA in the pancreas, and for both mediators in the liver and SAT. In ad lib fed Zucker rats, PEA and OEA levels were up to tenfold higher in the duodenum, slightly higher in the brainstem, and lower in the other tissues. Fasting/refeeding-induced changes in OEA levels were maintained in the duodenum, liver, and SAT, and lost in the pancreas, whereas fasting upregulated this compound also in the VAT. The observed changes in OEA levels in WT rats are relevant to the actions of this mediator on satiety, hepatic and adipocyte metabolism, and insulin release. OEA dysregulation in Zucker rats might counteract hyperphagia in the duodenum, but contribute to hyperinsulinemia in the pancreas, and to fat accumulation in adipose tissues and liver. Changes in PEA levels might be relevant to the inflammatory state of Zucker rats.
Related Concept Videos
Regulation of Food Intake
Metabolic States of the Body: Fasting and Starvation
cAMP-dependent Protein Kinase Pathways
Metabolic States of the Body: The Postabsorptive State
Initially, glycogen stored in the liver is broken down to release glucose into the bloodstream, while glycogen in the muscles is broken down to supply glucose for energy directly within the muscle cells. As glycogen stores diminish,...
Cell Specific Gene Expression
GPCRs Regulate Adenylyl Cylase Activity
Two...

