AUTORADIOGRAPHIC VISUALIZATION OF THE RECEPTOR SUBCLASSES FOR VASOACTIVE INTESTINAL POLYPEPTIDE (VIP) IN RAT-BRAIN

Vasoactive Intestinal Polypeptide (VIP) exerts its biological effects through interaction with two high affinity receptors named the VIP1- a nd the VIP2 receptors. Their messenger RNAs have been mapped in rat br ain by in situ hybridization. A cyclic peptide (RO 25-1553) and a secr etin analogue ([R-16]chicken secretin) were identified as selective ag onist peptides for the VIP2- and VIP1 receptors, respectively. The iod inated peptides retained the high affinity and selectivity of the unla belled peptides and were used for the mapping of each receptor subclas s in rat brain. VIP1 receptors were present in the cerebral cortex, th e piriform cortex, the claustrum, the caudate-putamen, the dentate gyr us, the lateral amygdaloid nucleus, the anteroventral thalamic nucleus , the rhomboid nucleus, the supraoptic nucleus and the choroid plexus. VIP2 receptors were present in the cerebral cortex: the claustrum, th e caudate-putamen, the nucleus accumbens, the lateral septal nuclei, t he bed nucleus of the stria terminalis, the basolateral amygdaloid nuc leus, the Ammon's horn, the thalamic nuclei except some centromedial n uclei, the medial habenula, the suprachiasmatic nucleus, the periventr icular nucleus, the mammilary nucleus, the superior colliculus and the choroid plexus. (C) 1997 Elsevier Science Inc.