CEFYBO   02669
CENTRO DE ESTUDIOS FARMACOLOGICOS Y BOTANICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
20. Participation of endocannabinoids in the control and peripheral inhibition of salivary secretion by alcohol
Autor/es:
JUAN PABLO PRESTIFILIPPO; JAVIER FERNÁNDEZ SOLARI; SAMUEL MCCANN; JUAN CARLOS ELVERDIN; BESUHLI DE RETTORI V
Lugar:
Quebec (Canada)
Reunión:
Simposio; XVII Symposium on the Cannabinoids; 2007
Resumen:
It is known that alcohol consumption decreases salivary secretion. Recently, we demonstrated that both cannabinoid receptors (CB1 and CB2) are present in the submandibulary gland of the rat (SMG). These receptors are coupled to Gi proteins that respond by inhibiting adenylyl cyclase activity. We hypothesized that ethanol (EtOH) might act through the cannabinoid system to inhibit salivary secretion in adult male Wistar rats. The gastric administration by gavage of EtOH (3g/Kg) inhibited at 1h the metacholin-stimulated saliva secretion that could be partially restored by intraglandular injection of the CB1 antagonist, AM251 (6.10-4M). Incubation in vitro of SMGs slices in the presence of AEA (10-9M) or EtOH (0.1M) for 30 min, significantly reduced the forskolin-increase of cAMP content (p<0.001 and p<0.05, respectively). The inhibitory effect of AEA was blocked significantly by AM251 (10-5M) and CB2 antagonist, AM630 (10-5M). However, the decrease of cAMP content by EtOH, was significantly blocked by AM251 but not AM630. Indicating that EtOH activated only CB1 receptor in the SMG. Furthermore, anandamide synthase activity measured by the radioconversion of 14C-arachidonic acid and ethanolamine to 14C-AEA was increased significantly (p<0.001) in SMG 1h after gastric administration of EtOH.  In summary, the present results demonstrated that the inhibitory effect produced by alcohol on salivary secretion is mediated, at least in part, by the endocannabinoid system. (Supported by Grant BID 1201 OC-AR, PICT 03/14264 and UBA-O-025)