Rapid desensitization of receptors for pituitary adenylate cyclase-activating polypeptide (PACAP) in chick cerebral cortex
Niewiadomski, P.Å‚; Nowak, J.Z.; Sedkowska, P.; Zawilska, J.B.
Polish Journal of Pharmacology 54(6): 717-721
2002
ISSN/ISBN: 1230-6002 PMID: 12866731 Document Number: 544762
Pituitary adenylate cyclase-activating polypeptide (PACAP38) potently stimulates cyclic AMP formation in slices of chick cerebral cortex. One- to fifteen-minute pretreatment of slices with 30 nM PACAP38 led to a time-dependent attenuation (when compared with values observed in the control tissue) of the cyclic AMP response produced by subsequent re-stimulation with 1 microM PACAP38. Concentration-response curve for restimulation with PACAP38 applied at 0.01-1 microM to tissue slices preincubated for 15 min with 30 nM PACAP38 revealed dose-dependent decreases in subsequent cyclic AMP responses by 16-37%. It is concluded that in chick cerebral cortex, the receptors mediating PACAP-driven cyclic AMP responses (PAC1 receptors) undergo rapid homologous desensitization.