am-630 and 1-6-bis(cyclohexyloximinocarbonyl)hexane

Secretory diarrhoea is a leading cause of mortality and morbidity worldwide. Our aim was to characterize the effect of inhibition of selected enzymes involved in the synthesis or degradation of endocannabinoids on electrolyte equilibrium in the mouse colonic tissue. The aim of this study was to evaluate the effects of PF-3845, JZL-184 and RHC-80267, as inhibitors of fatty acid amide hydrolase (FAAH), monoacylglycerol (MAGL) and diacylglycerol lipase (DAGL), respectively on epithelial ion transport in isolated mouse colon stimulated by forskolin (FSK), veratridine (VER) and bethanechol (BET). Next, colonic tissue was co-incubated with selected inhibitors and cannabinoid receptor antagonists: AM 251 and AM 630 (CB

Topics: Amidohydrolases; Animals; Benzodioxoles; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Cyclohexanones; Diarrhea; Endocannabinoids; Enzyme Inhibitors; Indoles; Lipoprotein Lipase; Male; Mice; Monoglycerides; Piperidines; Pyrazoles; Pyridines; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2

Previously, we reported that intracerebroventricularly (i.c.v.) administered arginine-vasopressin evokes the secretion of noradrenaline and adrenaline from adrenal medulla through the brain phospholipase C- and diacylglycerol-mediated and cyclooxygenase-mediated mechanisms in rats. Diacylglycerol can be hydrolyzed by diacylglycerol lipase to 2-arachidonoyl-sn-glycerol, which may be further degradated by monoacylglycerol lipase to free arachidonic acid, a representative substrate of cyclooxygenase. Recently, 2-arachidonoyl-sn-glycerol has been recognized as a major endocannabinoid, which can modulate synaptic transmission in the brain. In the present experiment, therefore, we examined (1) a role of the brain 2-arachidonoyl-sn-glycerol as a precursor of arachidonic acid in the centrally administered vasopressin-induced elevation of plasma noradrenaline and adrenaline, and (2) a regulatory role of the brain 2-arachidonoyl-sn-glycerol as an endocannabinoid on the vasopressin-induced response, using urethane-anesthetized rats. The vasopressin (0.2 nmol/animal, i.c.v.)-induced elevation of plasma catecholamines was reduced by RHC-80267 (diacylglycerol lipase inhibitor) (1.3 and 2.6 micromol/animal, i.c.v.) and also reduced by MAFP (monoacylglycerol lipase inhibitor) (0.7 and 1.4 micromol/animal, i.c.v.). MAFP (1.4 micromol/animal, i.c.v.) also attenuated the 2-arachidonoyl-sn-glycerol (0.5 micromol/animal, i.c.v.)-induced elevation of plasma catecholamines. AM 251 (cannabinoid CB(1) receptor antagonist) (90 and 180 nmol/animal, i.c.v.) potentiated the vasopressin (0.2 nmol/animal, i.c.v.)-induced response, while AM 630 (cannabinoid CB(2) receptor antagonist) (198 and 793 nmol/animal, i.c.v.) was largely ineffective. In addition, WIN 55212-2 (cannabinoid CB receptor agonist) (188 and 470 nmol/animal, i.c.v.) dose-dependently reduced the vasopressin-induced response. These results suggest that the brain 2-arachidonoyl-sn-glycerol generated from diacylglycerol plays a role as a precursor of arachidonic acid in the centrally administered vasopressin-induced activation of the adrenomedullary outflow, and also negatively regulates the peptide-induced central response through the brain cannabinoid CB(1) receptors in rats.

Topics: Adrenal Medulla; Animals; Arachidonic Acids; Arginine Vasopressin; Benzoxazines; Brain; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Cannabinoid Receptor Modulators; Catecholamines; Cyclohexanones; Dose-Response Relationship, Drug; Endocannabinoids; Enzyme Inhibitors; Epinephrine; Glycerides; Indoles; Injections, Intraventricular; Male; Morpholines; Naphthalenes; Norepinephrine; Organophosphonates; Piperidines; Pyrazoles; Rats; Rats, Wistar