Nitric oxide inhibition effect of chicken embryo development of lung

NO is an inorganic free radical which has important physiological roles, including defense against microorganisms which are mainly released by many cell types including epithelial cells. L-NG-Nitroarginine methyl ester (L-NAME) is a special Nitric Oxide (NO) synthesis inhibitor. In the related studies it is reported that nitric oxide syntheses inhibition leads to the increase of oxidants, under the oxidative stres causing to the increasing of both genotoxicity and cytotoxicity, adventually; triggering apoptosis. Moreover, intense and repeated oxidative stress in vivo may cause the pathologies of destruction of cytoskeleton structure, and loss of adhesion and pathologies that resulting in the cell loss. In our study, it is aimed to determine the effect on apoptosis and the distribution of laminin α1 through the inhibition of NO effect on the development of the chick lung is examined histologically. In this investigation; control, sham and L-NAME (15-30 mg/kg dose) have been treated in chick embryos, in lung development phases; immunohistochemistry method for eNOS, iNOS and Laminin α1 distribution, TUNEL method for apoptosis and hematoxylin-eosin staining for general histological Analysing have been applied. It was observed that the chick lung development is consisting with the 4 stages; embryonic (4-7 days), pseudoglandular (8-14 days), canalicular (14-17 days) and saccular stage (17. days - postnatal) and very similar to mammalian lung development. NO inhibition caused cell loss in mesenchymal tissue, significant reduction in airway branching and lung volume, reduction in luminal diameter of the bronchi, pulmonary embolism, alveolar proteinosis, regional bleeding, irregular modeling of blood vessels and contraction in its diameter. It was observed that during the early period of the development, depends on the LNAME application eNOS, iNOS and laminin α1 by immunoreactivity apoptosis is much reduced; increased in late stages of development and decrease slightly and remained stable after that. As a result it is determined that inhibition of NO has a negative impact both on lung development as well as on the composition of intracellular substances and apoptosis. This adversely leads to many histopathological conditions that affect the lifetime and its quality.