RT info:eu-repo/semantics/article T1 5-Hydroxytryptamine decreases somatostatin receptors and somatostatin-responsive adenylyl cyclase in rat pancreatic acinar membranes A1 Muñoz Acedo, Gema A1 Rodríguez Martín, Eulalia A1 Puebla Jiménez, Lilian A1 Arilla Ferreiro, Eduardo K1 Somatostatin K1 Serotonin K1 Pancreas K1 Bioquímica K1 Biochemistry K1 Science K1 Ciencia AB Pretreatment of pancreatic acini with 5-hydroxytryptamine (5-HT) reduced the binding of the labeled somatostatin (SS) analogue 125I-Tyr3-SMS to pancreatic acinar membranes. This effect was dependent of the dose of 5-HT used and length of pretreatment. This inhibitory effect of 5-HT was abolished when pancreatic acini were pretreated with 5-HT in the presence of the 5-HT1P receptor-antagonist 5-hydroxytryptophyl-5-hydroxytryptophan amide (5-HTP-DP). Pretreatment of pancreatic acini with 5-HT reduced the inhibition by the stable SS analogue SMS 201-995 of basal and forskolin (FK)-stimulated adenylyl cyclase (AC) activity in pancreatic acinar membranes. There was no statistical difference established between IC50 values for the stable GTP analogue 5'-guanylylimidodiphosphate (Gpp(NH)p) which inhibits ligand binding to SMS receptors in controls and in 5-HT treated pancreatic cells, respectively. In addition, no significant differences were seen in the level of Gi proteins in the control and 5-HT treated panceatic acini. These data suggest that the decrease of the number of 125I-Tyr3-SMS receptors, would explain the decreased sensitivity of AC to SMS 201-995 in membranes from 5-HT-pretreated acini. PB Elsevier SN 0024-3205 YR 1997 FD 1997 LK http://hdl.handle.net/10017/2248 UL http://hdl.handle.net/10017/2248 LA eng NO Universidad de Alcalá DS MINDS@UW RD 28-mar-2024