We examined the localization of the pituitary adenylate cyclase-activating
peptide (PACAP) receptor (PAC1-R) and its mRNA with immunocytochemistry and
in situ hybridization, respectively. PAC1-R immunoreactivity and its trans
cript were detected in both chromaffin cells and ganglion cells but not det
ected in the adrenal cortex. In addition, strong PAC1-R immunoreactivity wa
s found beneath the plasma membrane of the immunoreactive medullary cells.
Electron microscopic immunocytochemistry revealed that PAC1-R was predomina
ntly expressed in adrenaline-containing cells. This report supports the not
ion that PACAP is an activator and modulator of catecholamine secretion as
well as synthesis in the adrenal medulla. (C) 2000 Published by Elsevier Sc
ience Ireland Ltd.