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This Article Full Text Full Text (PDF) All Versions of this Article: 295/1/L201    most recent 00264.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Peyter, A.-C. Articles by Tolsa, J.-F. PubMed PubMed Citation Articles by Peyter, A.-C. Articles by Tolsa, J.-F.

Muscarinic receptor M₁ and phosphodiesterase 1 are key determinants in pulmonary vascular dysfunction following perinatal hypoxia in mice

¹Neonatal Research Laboratory, Department of Pediatrics, and ²Division of Critical Care, Department of Internal Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland

Perinatal adverse events such as limitation of nutrients or oxygen supply are associated with the occurrence of diseases in adulthood, like cardiovascular diseases and diabetes. We investigated the long-term effects of perinatal hypoxia on the lung circulation, with particular attention to the nitric oxide (NO)/cGMP pathway. Mice were placed under hypoxia in utero 5 days before delivery and for 5 days after birth. Pups were then bred in normoxia until adulthood. Adults born in hypoxia displayed an altered regulation of pulmonary vascular tone with higher right ventricular pressure in normoxia and increased sensitivity to acute hypoxia compared with controls. Perinatal hypoxia dramatically decreased endothelium-dependent relaxation induced by ACh in adult pulmonary arteries (PAs) but did not influence NO-mediated endothelium-independent relaxation. The M₃ muscarinic receptor was implicated in the relaxing action of ACh and M₁ muscarinic receptor (M₁AChR) in its vasoconstrictive effects. Pirenzepine or telenzepine, two preferential inhibitors of M₁AChR, abolished the adverse effects of perinatal hypoxia on ACh-induced relaxation. M₁AChR mRNA expression was increased in lungs and PAs of mice born in hypoxia. The phosphodiesterase 1 (PDE1) inhibitor vinpocetine also reversed the decrease in ACh-induced relaxation following perinatal hypoxia, suggesting that M₁AChR-mediated alteration of ACh-induced relaxation is due to the activation of calcium-dependent PDE1. Therefore, perinatal hypoxia leads to an altered pulmonary circulation in adulthood with vascular dysfunction characterized by impaired endothelium-dependent relaxation and M₁AChR plays a predominant role. This raises the possibility that muscarinic receptors could be key determinants in pulmonary vascular diseases in relation to "perinatal imprinting."

muscarinic receptors; phosphodiesterases; endothelial nitric oxide synthase; pulmonary artery; acetylcholine