283 PULMONARY NEUROENDOCRINE CELLS (PNEC) IN NEONATAL RATS WITH CONGENITAL DIAPHRAGMATIC HERNIA (CDH)

Abstract

Lung hypoplasia and persistent pulmonary hypertension are the principal causes of high mortality and morbidity in infants with CDH. Amine and peptide producing PNEC, widely distributed throughout airway mucosa, are thought to play an important role in both pulmonary development and in regulation of pulmonary vascular tone. Furthermore, recent studies show modulation during chronic hypoxia of calcitonin gene-related peptide (CGRP), a pulmonary vasodilator produced by PNEC (Anat Rec 1993,236:96). We report data on morphometric analysis of CGRP immunoreactive PNEC clusters (neuroepithelial bodies, NEB) in a neonatal rat model of CDH induced by oral administration of Nitrofen to pregnant rats at 10 days of gestation (J Ped Surg 1990,25:850). Sections of lungs from term neonatal rats with CDH and controls were immunostained for CGRP (marker of NEB) with specific antibody against rat CGRP. NEB size and number of NEB/area of lung were assessed using semiautomatic image analysis system.Our findings show that in lungs of neonatal rats with CDH, there is an increase in relative freguency of NEB per surface area of lung parenchyma, while the size of NEB is not significantly affected. Whether this results in altered NEB function including imbalance in vasoactive Mediators requires further studies.(Supported by NAF 91.56).