title: Pituitary adenylate cyclase-activating polypeptide (PACAP) induces relaxations of peripheral and cerebral arteries, which are differentially impaired by aging.
abstract: Pituitary adenylate cyclase-activating polypeptide (PACAP) is a well-known neuropeptide, which also has vasomotor effects. However, little is known regarding its age-related and organ-specific vasomotor effects. We hypothesized that the vasomotor effects of PACAP depend on the tissue origin of the vessels and aging substantially modulates its actions. Thus, carotid (CA) and basilar arteries (BA) were isolated from young (2 months old), middle age (12 months old), and old (30 months old) rats. Their vasomotor responses were measured with an isometric myograph (DMT610M) in response to cumulative concentrations of PACAP1-38 (10(-9)-10(-6) M). PACAP1-38 induced (1) significantly greater concentration-dependent relaxations in CA compared to that of BA of young, middle age, and old rats; (2) relaxations of CA significantly decreased, whereas they did not change substantially in BA, as a function of age; (3) sodium nitroprusside (SNP)-induced relaxation did not change after PACAP1-38 administration in any conditions; and (4) inhibition of PAC1 receptors by selective PAC1 receptor blocker (PACAP6-38) completely diminished the responses to PACAP in all age groups of BA and CA. In conclusion, these findings suggest that PACAP1-38 has greater vasomotor effect in CA than that in BA, whereas aging has less effect on PACAP-induced relaxation of cerebral arteries and BA than that in peripheral arteries and CA suggesting that the relaxation to PACAP is maintained in cerebral arteries even in old age.
authors.affiliation: Department of Pathophysiology and Gerontology, Szentagothai Research Centre, University of Pecs, Medical School, Szigeti út 12, Pecs, 7624, Hungary.
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Vamos
authors.forename: Ivan
authors.initials: I
authors.lastname: Ivic
authors.forename: Peter
authors.initials: P
authors.lastname: Cseplo
authors.forename: Gabor
authors.initials: G
authors.lastname: Toth
authors.forename: Andrea
authors.initials: A
authors.lastname: Tamas
authors.forename: Dora
authors.initials: D
authors.lastname: Reglodi
authors.forename: Akos
authors.initials: A
authors.lastname: Koller
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001488:Basilar Artery / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D002339:Carotid Arteries / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D008297:Male; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014664:Vasodilation
chemical_list: D051219:Pituitary Adenylate Cyclase-Activating Polypeptide