PULMONARY NEUROENDOCRINE CELLS IN NEONATAL RATS WITH CONGENITAL DIAPHRAGMATIC-HERNIA

Lung hypoplasia and persistent pulmonary hypertension are the principa l causes of high mortality and morbidity in infants with congenital di aphragmatic hernia (CDH). Amine and peptide producing pulmonary neuroe ndocrine cells (PNEC), widely distributed throughout the airway mucosa , are thought to play an important role in both pulmonary development and regulation of pulmonary vascular tone. Furthermore, recent studies show increased levels of calcitonin gene-related peptide (CGRP), a pu lmonary vasodilator produced by PNEC, during chronic hypoxia. The arti cle reports data on morphometric analysis of CORP immunoreactive PNEC clusters (neuroepithelial bodies, NEB) in a rat model of CDH. CDH was induced in neonatal Sprague Dawley rats by oral administration of 2,4- dichloro-phenyl-p-nitrophenylether (Nitrofen; Rohm Haas, Philadelphia, PA) to the mother at 10 days of gestation. Sections of lungs from ter m neonatal rats with and without CDH and controls were immunostained f or CGRP (marker of NEB) with specific antibody against rat CGRP. NEB s ize and number of NEB/area of lung were assessed using a semiautomatic image analysis system. In lungs of neonatal rats with CDH, the number of NEB per surface area of lung parenchyma was significantly increase d compared with the age matched controls, Although the mean size of NE B was larger in CDH, the differences were not significant. This is the first study of PNEC in CDH. Whether the phenomenon observed in this s tudy results in altered NEB function including imbalance in vasoactive mediators requires further studies, especially in the human being. Co pyright (C) 1995 by W.B. Saunders Company