Pathophysiologic mechanisms of persistent pulmonary hypertension of the newborn.
Persistent pulmonary hypertension of the newborn (PPHN), among the most rapidly progressive and potentially fatal of vasculopathies, is a disorder of vascular transition from fetal to neonatal circulation, manifesting as hypoxemic respiratory failure. PPHN represents a common pathway of vascular injury activated by numerous perinatal stresses: hypoxia, hypoglycemia, cold stress, sepsis, and direct lung injury. As with other multifactorial diseases, a single inciting event may be augmented by multiple concurrent/subsequent phenomena that result in differing courses of disease progression. I review the various mechanisms of vascular injury involved in neonatal pulmonary hypertension: endothelial dysfunction, inflammation, hypoxia, and mechanical strain, in the context of downstream effects on pulmonary vascular endothelial-myocyte interactions and myocyte phenotypic plasticity.
Dakshinamurti
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Department of Pediatrics, University of Manitoba, Manitoba Institute of Child Health, Winnipeg, Canada. dakshina@cc.umanitoba.ca
D004730:Endothelium, Vascular / Q000503:physiopathology; D006801:Humans; D000860:Hypoxia / Q000209:etiology / Q000503:physiopathology; D007231:Infant, Newborn; D007249:Inflammation / Q000209:etiology / Q000503:physiopathology; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology; D010547:Persistent Fetal Circulation Syndrome / Q000150:complications / Q000503:physiopathology*; D011652:Pulmonary Circulation