glyceryl-2-arachidonate and Hyperinsulinism

To measure the circulating levels of endocannabinoids and related molecules at fasting, after acute hyperinsulinemia and after weight loss in insulin sensitive vs. insulin resistant obese postmenopausal women.. The sample consisted of 30 obese postmenopausal women (age: 58.9 ± 5.2 yrs; BMI: 32.9 ± 3.6 kg/m(2) ). Subjects underwent a 3-hour hyperinsulinaemic-euglycaemic clamp (HEC) (glucose disposal rate (M-value): 10.7 ± 3.3 mg min(-1) kg(-1) FFM) and 6-month weight loss intervention. Participants were classified as insulin sensitive obese (ISO) or insulin resistant obese (IRO) based on a predefined cutoff. Plasma levels of the endocannabinoids, anandamide (AEA), 2-arachidonoylglycerol (2-AG), and of the AEA-related compounds, palmitoylethanolamide (PEA) and oleoylethanolamide (OEA), were measured by liquid chromatography-mass spectrometry.. IRO presented higher levels of 2-AG (P < 0.05) independently of the HEC and weight loss, whereas the HEC had an independent inhibitory effect on AEA, PEA, and OEA levels (P < 0.05) in both groups. Furthermore, there was an independent stimulatory effect of weight loss only on PEA levels in both groups (P < 0.05).. This study is the first to show that higher circulating levels of the endocannabinoid 2-AG are found in IRO compared to ISO postmenopausal women, and that weight loss is associated with an increase in PEA, a PPAR-α ligand.

Topics: Amides; Arachidonic Acids; Body Composition; Body Mass Index; Cholesterol, HDL; Cholesterol, LDL; Cohort Studies; Endocannabinoids; Ethanolamines; Female; Glucose Clamp Technique; Glycerides; Humans; Hyperinsulinism; Insulin; Insulin Resistance; Middle Aged; Obesity; Oleic Acids; Palmitic Acids; Polyunsaturated Alkamides; Postmenopause; Triglycerides; Weight Loss

Endocannabinoid signaling has been implicated in modulating insulin release from β cells of the endocrine pancreas. β Cells express CB1 cannabinoid receptors (CB1Rs), and the enzymatic machinery regulating anandamide and 2-arachidonoylglycerol bioavailability. However, the molecular cascade coupling agonist-induced cannabinoid receptor activation to insulin release remains unknown. By combining molecular pharmacology and genetic tools in INS-1E cells and in vivo, we show that CB1R activation by endocannabinoids (anandamide and 2-arachidonoylglycerol) or synthetic agonists acutely or after prolonged exposure induces insulin hypersecretion. In doing so, CB1Rs recruit Akt/PKB and extracellular signal-regulated kinases 1/2 to phosphorylate focal adhesion kinase (FAK). FAK activation induces the formation of focal adhesion plaques, multimolecular platforms for second-phase insulin release. Inhibition of endocannabinoid synthesis or FAK activity precluded insulin release. We conclude that FAK downstream from CB1Rs mediates endocannabinoid-induced insulin release by allowing cytoskeletal reorganization that is required for the exocytosis of secretory vesicles. These findings suggest a mechanistic link between increased circulating and tissue endocannabinoid levels and hyperinsulinemia in type 2 diabetes.

Topics: Animals; Arachidonic Acids; Cannabinoid Receptor Agonists; Cell Line; Diabetes Mellitus, Type 2; Endocannabinoids; Enzyme Activation; Exocytosis; Focal Adhesion Kinase 1; Glycerides; Humans; Hyperinsulinism; Insulin; Insulin Secretion; Insulin-Secreting Cells; Mice; Mice, Knockout; Polyunsaturated Alkamides; Proto-Oncogene Proteins c-akt; Receptor, Cannabinoid, CB1; Secretory Vesicles