Pulmonary Neuroendocrine Cell-Secreted Factors May Alter Fetal Lung Liquid Clearance

Abstract

ABSTRACT:The neuroendocrine system is most active at birth and may play a role in the transition from fetal to postnatal life, in particular in the lungs' transition from fluid secretion to fluid absorption. Pulmonary neuroendocrine cells do release dopamine (DA), serotonin, and gastrin-releasing peptide but their effects on lung ion and fluid transport are poorly understood. Therefore, we studied their effects on fetal distal lung explants and primary cultures of fetal distal lung epithelium (FDLE). We show that DA, but neither serotonin nor gastrin-releasing peptide, alters ion and fluid transport, in a dosedependent manner. DAs effects were abrogated by D1/D2 receptor blockers in FDLE but not in explants. Propranolol abrogated DAs effects in both models. DA increased intracellular cAMP levels in FDLE. Terbutaline, forskolin, and isobutylmethylxanthine did not increase short circuit current (Isc) in DA-treated cells, despite a further increase in cAMP. We conclude that at least one, but not all mediators released by pulmonary neuroendocrine cells alter distal lung epithelial ion transport. (Pediatr Res 65: 274-278, 2009)

Effect of adrenalectomy on pulmonary edema resolution

“…Previous studies using the thiourea-induced lung injury model have shown histologically that there was significant edema accumulation in the alveolus and in the interstitial space [17,19]. This accumulation of liquid in the lung could trigger physiological responses known to stimulate lung neuroendocrine cells [26], which can release amines, such as serotonin [26,27] or dopamine [28], which are known to stimulate lung liquid clearance [28][29][30][31]. Future experiments are needed to explore this hypothesis.…”