title: V-shaped cushion at the origin of bovine pulmonary supernumerary arteries: structure and putative function.
abstract: This study investigates the anatomic structure at the origin of pulmonary supernumerary arteries and their parent conventional artery. Histological examination showed that at the origin of each supernumerary artery the wall of the parent conventional artery is organized into a distinct V-shaped structure, which begins on the hilum side of each supernumerary artery as a funnel-shaped channel running into the supernumerary artery. The base of the channel is particularly thin walled. The lateral walls of the channel are composed of musculoelastic cushions that become more pronounced toward the supernumerary artery and fuse on its distal side, forming a baffle that projects over the supernumerary artery lumen. These V-shaped structures/cushions were observed with video stereo dissecting microscopy in both an open and closed state in isolated arteries in vitro. Pulmonary vasoconstriction of isolated arteries with the thromboxane A(2) mimetic U-46619 increased the number of V-shaped structures in the closed state. These studies indicate the presence of a novel anatomic structure at the origin of pulmonary supernumerary arteries, which may be able to regulate blood flow into the supernumerary artery.
authors.affiliation: School of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, United Kingdom. a.m.shaw@gcal.ac.uk
authors.forename: A M
authors.initials: AM
authors.lastname: Shaw
authors.forename: D C
authors.initials: DC
authors.lastname: Bunton
authors.forename: A
authors.initials: A
authors.lastname: Fisher
authors.forename: J C
authors.initials: JC
authors.lastname: McGrath
authors.forename: I
authors.initials: I
authors.lastname: Montgomery
authors.forename: C
authors.initials: C
authors.lastname: Daly
authors.forename: A
authors.initials: A
authors.lastname: MacDonald
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D004210:Dissection; D066298:In Vitro Techniques; D018613:Microscopy, Confocal; D011651:Pulmonary Artery / Q000033:anatomy & histology* / Q000187:drug effects / Q000502:physiology; D013690:Television; D014662:Vasoconstrictor Agents / Q000494:pharmacology
chemical_list: D014662:Vasoconstrictor Agents; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid