title: Vascular reactivity of pulmonary arteries from premature lambs subjected to liquid ventilation.
abstract: This study aimed to evaluate the effect of tidal liquid ventilation (TLV) and liquid assisted high frequency oscillatory ventilation (LA-HFOV) on the contractile and relaxing properties of fetal ovine pulmonary arteries. 0.85 term lambs were subjected, after surfactant instillation, to 5 h of TLV or LA-HFOV (5 ml.kg(-1) perfluorocarbon liquid). After euthanasia of the animals, intrapulmonary arteries (fourth branch) were dissected and mounted in a myograph for isometric tension recording. Arteries from unventilated age-matched fetuses were also studied. The contractions induced by K(+), and the thromboxane A(2) mimetic U46619 were not significantly different in the TLV and the LA-HFOV groups. Acetylcholine-induced relaxation was absent after TLV and LA-HFOV but present in unventilated animals. Sodium nitroprusside-induced relaxation was also similar after TLV and LA-HFOV, but reduced when the two groups were compared with unventilated fetuses. We conclude that after TLV and LA-HFOV the pulmonary arterial responses to receptor- and non receptor-mediated contraction and to endothelium-dependent and -independent relaxation were similar.
authors.affiliation: Department of Pediatrics, University Hospital Maastricht, Research Institute Growth and Development (GROW), University of Maastricht, P. Debyelaan 25, PO Box 5800, NL-6202 AZ Maastricht, The Netherlands. eiv@paed.azm.nl
authors.forename: Eduardo
authors.initials: E
authors.lastname: Villamor
authors.forename: Pieter L J
authors.initials: PL
authors.lastname: Degraeuwe
authors.forename: Jo G R
authors.initials: JG
authors.lastname: De Mey
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Blanco
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D005865:Gestational Age; D021061:Liquid Ventilation; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000502:physiology; D009599:Nitroprusside / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011651:Pulmonary Artery / Q000502:physiology*; D012756:Sheep; D013928:Thromboxane A2 / Q000494:pharmacology
chemical_list: D009599:Nitroprusside; D013928:Thromboxane A2; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000109:Acetylcholine; D011188:Potassium