title: Endothelium-denuded pulmonary resistance arteries from the fetal lamb: preparation and response to vasoactive agents.
abstract: A method was developed for preparing endothelium-denuded resistance arteries (mean internal diameter, 176 microns) from the term fetal lung to be used for tests in vitro. The endothelium was removed mechanically by passing a sandpaper-polished cat whisker through the lumen. Ultrastructurally, the preparation had a well-preserved internal elastic lamina which was facing the lumen without any endothelium superimposed. Its response to contractile agents (excess potassium, a thromboxane A2 analogue, endothelin-1) tended to be greater compared to the intact artery. Conversely, the relaxation to acetylcholine was abolished in the endothelium-denuded artery and, in its place, a modest contraction ensued. Sodium nitroprusside relaxation, unlike acetylcholine relaxation, was affected insignificantly by endothelium denudation. This preparation, in combination with the preparation of the intact resistance artery, is a useful, new tool for studying local factors responsible for pulmonary hemodynamic control in utero and through the transitional period at birth.
authors.affiliation: Research Institute, Hospital for Sick Children, Toronto, Canada.
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: A
authors.initials: A
authors.lastname: Mercer-Connolly
authors.forename: L
authors.initials: L
authors.lastname: Lines
authors.forename: O
authors.initials: O
authors.lastname: Toyoda
authors.forename: F
authors.initials: F
authors.lastname: Coceani
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001158:Arteries; D002415:Cats; D004305:Dose-Response Relationship, Drug; D016232:Endothelins / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000648:ultrastructure; D005333:Fetus; D006197:Hair / Q000648:ultrastructure; D006439:Hemodynamics / Q000187:drug effects; D008168:Lung / Q000098:blood supply* / Q000187:drug effects / Q000196:embryology; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009599:Nitroprusside / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011652:Pulmonary Circulation / Q000187:drug effects* / Q000502:physiology; D012756:Sheep / Q000196:embryology; D013928:Thromboxane A2 / Q000494:pharmacology; D014655:Vascular Resistance / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D016232:Endothelins; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D009599:Nitroprusside; D013928:Thromboxane A2; D000109:Acetylcholine; D011188:Potassium