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Sympathetic modulation of hypoxic pulmonary vasoconstriction in intact dogs

par Brimioulle, Serge ;Vachiery, Jean-Luc ;Brichant, Jean-François;Delcroix, Marion ;Lejeune, Philippe ;Naeije, Robert
Référence Cardiovascular Research, 34, 2, page (384-392)
Publication Publié, 1997-05

Article révisé par les pairs

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Résumé :

Background: The effects of the sympathetic nervous system on hypoxic pulmonary vasoconstriction (HPV) have been reported variably. We studied the effects of adrenergic receptor blockade on HPV in 32 pentobarbital- anaesthetised intact dogs. Methods: Pulmonary arterial flow-pressure relationships were determined in hyperoxia and hypoxia, at baseline and after α-blockade (phentolamine 2 mg/kg + 50 μg · kg-1 · h-1), β-blockade (propranolol 2 mg/kg), αβ-blockade, epidural blockade (lignocaine 20 mg/kg), and αβ- plus epidural blockade. Results: At reference flow of 3.5 l · min-1 · m-2, the mean hypoxic response (hypoxia-induced increase in transpulmonary pressure gradient, each n = 8) changed from 6.0 ± 0.9 to 3.5 ± 1.0 mmHg after α-blockade, from 5.8 ± 0.09 to 7.3 ± 0.7 mmHg after β- blockade, from 4.1 ± 0.8 to 9.0 ± 1.4 mmHg after αβ-blockade, and from 3.4 ± 1.0 to 4.3 ± 0.9 mmHg after epidural blockade (all P < 0.05), and was not affected by epidural blockade after αβ-blockade: Conclusions: In pentobarbital-anaesthetised dogs, (1) HPV is attenuated by α- and enhanced by β-, αβ- and epidural blockade, and (2) epidural blockade has no significant adrenergic-unrelated effect on the pulmonary vasculature.