Y. Shiotani et al., IMMUNOHISTOCHEMICAL LOCALIZATION OF PITUITARY ADENYLATE CYCLASE-ACTIVATING POLYPEPTIDE (PACAP) IN THE ADRENAL-MEDULLA OF THE RAT, Peptides, 16(6), 1995, pp. 1045-1050
Localization of PACAP in rat adrenal glands was examined by light and
electron microscopic immunohistochemistry using a specific antiserum t
o PACAP 38, R0831. In the light microscopic study, PACAP immunoreactiv
ity was observed in some cell groups in the medulla, but not in the co
rtex. In comparison with adjacent sections stained with antisera to ca
techolamine synthesizing enzymes, PACAP-positive cells were immunoreac
tive to tyrosine hydroxylase and dopamine beta-hydroxylase, but not to
phenylethanolamine-N-methyltransferase, suggesting that they were coi
ncident with noradrenaline secreting cells. In the electron microscopi
c study using the ABC method, DAB reaction products were diffusely dis
tributed in the cytoplasmic matrix of PACAP-positive cells, without in
tense accumulation on the secretory granules. The splanchnic nerve ter
minals were PACAP negative. In postembedding immunohistochemistry, gol
d particles were localized diffusely in the cytoplasma, but not aggreg
ated on the secretory granules. It was suggested that PACAP would loca
lize in the cytoplasmic matrix of noradrenaline cells and stimulate th
e catecholamine synthesis and release in the adrenal medulla.