title: Evidence for a possible synergism between pituitary adenylate cyclase activating polypeptide and calcitonin gene-related peptide in porcine ophthalmic artery.
abstract: The activities of pituitary adenylate cyclase activating polypeptide (PACAP) and calcitonin gene-related peptide (CGRP) were investigated in isolated segments of porcine ophthalmic artery. In artery segments pre-contracted by prostaglandin F2alpha, PACAP induced a concentration dependent relaxation, but was clearly less potent than CGRP. When 2 x 10(-10) M CGRP (relaxation 4.3 +/- 0.8%, n = 11) and 10(-8) M PACAP (relaxation 12.4 +/- 3.8%, n = 10) were added together, the subsequent relaxation was substantially increased (33.6 +/- 5.6%, p<0.0005). In addition, the rate of relaxation was increased. The results indicate that there is synergism between low concentrations of CGRP and PACAP in isolated porcine ophthalmic artery.
authors.affiliation: Department of Ophthalmology, University Hospital of Trondheim, Norway.
authors.forename: T
authors.initials: T
authors.lastname: Elsås
authors.forename: L R
authors.initials: LR
authors.lastname: White
mesh_terms: D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D066298:In Vitro Techniques; D009126:Muscle Relaxation / Q000187:drug effects / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology; D009479:Neuropeptides / Q000008:administration & dosage / Q000494:pharmacology*; D018377:Neurotransmitter Agents / Q000008:administration & dosage / Q000494:pharmacology*; D009880:Ophthalmic Artery / Q000187:drug effects* / Q000502:physiology; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D013552:Swine; D014664:Vasodilation / Q000187:drug effects
chemical_list: D009479:Neuropeptides; D018377:Neurotransmitter Agents; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D015740:Calcitonin Gene-Related Peptide