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Neuronal nitric oxide synthase does not contribute to the modulation of pulmonary vascular tone in fetal lambs with congenital diaphragmatic hernia (nNOS in CDH lambs)
Author(s) -
Roessingh Anthony S. de Buys,
de Lagausie Pascal,
Ibrahima Taline,
DuongQuy Sy,
Schneider JeanChristophe,
Huang XiaoLin,
Mercier JeanChristophe,
Aigrain Yves,
Boulanger Chantal,
DinhXuan Anh Tuan
Publication year - 2008
Publication title -
pediatric pulmonology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.866
H-Index - 106
eISSN - 1099-0496
pISSN - 8755-6863
DOI - 10.1002/ppul.20796
Subject(s) - congenital diaphragmatic hernia , medicine , nitric oxide , nitric oxide synthase , pulmonary artery , diaphragmatic breathing , vascular resistance , pulmonary hypertension , diaphragmatic hernia , endocrinology , fetus , anesthesia , hernia , pathology , hemodynamics , surgery , biology , pregnancy , genetics , alternative medicine
Aim The aim of this study was to determine the presence of the neuronal nitric oxide synthase (nNOS) in near full‐term lambs with congenital diaphragmatic hernia (CDH) and its role in the modulation of pulmonary vascular basal tone. Methods We surgically created diaphragmatic hernia on the 85th day of gestation. On the 135th, catheters were used to measure pulmonary pressure and blood flow. We tested the effects of 7‐nitroindazole (7‐NINA), a specific nNOS antagonist and of N ‐nitro‐ l ‐arginine ( l ‐NNA), a nonspecific nitric oxide synthase antagonist. In vitro, we tested the effects of the same drugs on isolated pulmonary vessels. The presence of nNOS protein in the lungs was detected by Western blot analysis. Results Neither 7‐NINA nor l ‐NNA modified pulmonary vascular basal tone in vivo. After l ‐NNA injection, acetylcholine (ACh) did not decrease significantly pulmonary vascular resistance (PVR). In vitro, l ‐NNA increased the cholinergic contractile‐response elicited by electric field stimulation (EFS) of vascular rings from lambs with diaphragmatic hernia. Conclusion We conclude that nNOS protein is present in the lungs and pulmonary artery of near full‐term lamb fetuses with diaphragmatic hernia, but that it does not contribute to the reduction of pulmonary vascular tone at birth. Pediatr Pulmonol. 2008; 43:313–321. © 2008 Wiley‐Liss, Inc.