Vascular reactivity of pulmonary arteries from premature lambs subjected to liquid ventilation.
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.
Villamor
Eduardo
E
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
Degraeuwe
Pieter L J
PL
De Mey
Jo G R
JG
Blanco
Carlos E
CE
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
D009599:Nitroprusside; D013928:Thromboxane A2; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000109:Acetylcholine; D011188:Potassium