THE TYPE-I PACAP RECEPTOR AND ITS BIOLOGICAL-ACTIVITIES

The neuropeptide PACAP acts through type I receptors (that display sel ectivity for PACAP-38 and PACAP-27 as compared to VIP) and type II (VI P) receptors showing similar high affinity for PACAP-27, PACAP-38 and VIP. The dual coupling of type I receptors to adenylate cyclase and PL C has several consequences including on gene expression. In the hypoth alamo-pituitary axis, also in the central nervous system outside the h ypothalamus, in adrenals, arteries and microvasculature, heart, lungs, digestive tract and testes, PACAP appears to play a series of importa nt and relatively specific biological functions.