The distribution of pituitary adenylate cyclase-activating polypeptide-like immunoreactivity is distinct from helodermin- and helospectin-like immunoreactivities in the rat brain.
Pituitary adenylate cyclase-activating polypeptide (PACAP) is an amidated 38-residue polypeptide isolated from the ovine hypothalamus. Helodermin, a 35-amino acid peptide, and helospectins, peptides of 38 and 37 amino acid residues, have been isolated from lizard venom. PACAP, helodermin and helospectins share structural features and have a similar profile of pharmacological effects: they stimulate adenylate cyclase. We studied the distribution and characteristics of PACAP-like immunoreactivity in the rat brain with immunochemical and immunohistochemical methods and compared its distribution with that of helodermin- and helospectin-like immunoreactivities. With radioimmunoassay, the highest concentrations of PACAP-like immunoreactivity were found in the hypothalamus and cerebellum. PACAP-immunoreactive cell bodies were located immunohistochemically in the supraoptic nucleus, paraventricular and periventricular hypothalamic nuclei, and in the central grey. PACAP-immunoreactive fibres and terminals were detected in the medial part of the central nucleus of amygdala, in the median eminence and neurohypophysis, and in the central grey. No PACAP-immunoreactive structures were observed in areas such as the cerebral cortex, hippocampus, or cerebellum. The distribution of PACAP-like immunoreactivity differed considerably from the distribution of helodermin- and helospectin-like immunoreactivities. The results of this study suggest that PACAP is a neuropeptide with a role in the regulation of endocrine function in the hypothalamo-hypophyseal axis.
Kivipelto
L
L
Department of Anatomy, University of Helsinki, Finland.
Absood
A
A
Arimura
A
A
Sundler
F
F
Håkanson
R
R
Panula
P
P
D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000276:immunology / Q000378:metabolism*; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins; D008297:Male; D009479:Neuropeptides / Q000276:immunology / Q000378:metabolism*; D010455:Peptides / Q000276:immunology / Q000378:metabolism*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains
C495403:Adcyap1 protein, rat; D036341:Intercellular Signaling Peptides and Proteins; D009479:Neuropeptides; D010455:Peptides; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; C040442:heliodermin; C043046:helospectin I; C043047:helospectin II