RT Journal Article SR Electronic T1 Abundance of endothelial nitric oxide synthase in newborn intrapulmonary arteries. JF Archives of Disease in Childhood - Fetal and Neonatal Edition JO Arch Dis Child Fetal Neonatal Ed FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP F17 OP F21 DO 10.1136/fn.73.1.F17 VO 73 IS 1 A1 Hislop, A. A. A1 Springall, D. R. A1 Buttery, L. D. A1 Pollock, J. S. A1 Haworth, S. G. YR 1995 UL http://fn.bmj.com/content/73/1/F17.abstract AB A monoclonal antibody to endothelial NOS (eNOS) was used to demonstrate the distribution and density of eNOS in the developing porcine lung. Lung tissue from large white pigs aged from less than 5 minutes to 3 months was immunostained and, using light microscopy, distribution of eNOS was assessed by a semiquantitative scoring system. At all ages eNOS was located on the endothelial cells of pulmonary and bronchial arteries and veins. Immunoreactivity for eNOS was greater in the larger, more proximal pulmonary arteries than at the periphery. In the lung of newborn pigs immunoreactivity for eNOS was present in arteries of all sizes but some showed no positive staining. At 2-3 days of age almost all arteries showed positive immunoreactivity. By 3 months of age the amount of eNOS had decreased and was less than that seen in the newborn. The highest level of eNOS was seen immediately after birth when the pulmonary arteries are dilating. eNOS may therefore play an important part in adaptation to extra-uterine life.