title: Nitric oxide modulates branching morphogenesis in fetal rat lung explants.
abstract: Cells of the developing lung express the constitutive nitric oxide synthases (NOSs) I and III. The developmental importance of these enzymes is largely unknown, although a role for nitric oxide (NO) in the regulation of pulmonary blood flow at birth is established. Known effects of NO on transcription factors, apoptosis, and cellular proliferation, plus the time and spatial limits of pulmonary NOS expression, suggest that NO might influence lung development. We tested the potential of NO to modulate lung branching morphogenesis by exposing lung explants from gestational day 13 rat fetuses to varying doses of several NO donors (NONO-ate). We counted the number of airway branches that were added between the first and 72nd h of culture. NO released only from a NONO-ate with a long half-life [(Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl)amino]-diazen-1-ium-1,2-diolate-NO], increased branching in ambient O(2) by twofold. The NO effect was not mimicked with a cyclic guanine monophosphate analog; nonspecific NOS inhibitors in millimolar concentrations inhibited branching. We conclude that endogenous and exogenous NO can modulate branching morphogenesis in the rat lung.
authors.affiliation: Duke University and Durham Veterans Affairs Medical Centers, Durham, North Carolina 27705, USA. stephen.young@duke.edu
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Young
authors.forename: Katherine
authors.initials: K
authors.lastname: Evans
authors.forename: Jerry P
authors.initials: JP
authors.lastname: Eu
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism; D006152:Cyclic GMP / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005314:Embryonic and Fetal Development / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005333:Fetus / Q000378:metabolism; D008168:Lung / Q000196:embryology* / Q000201:enzymology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III; D009924:Organ Culture Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014226:Triazenes / Q000494:pharmacology; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: C105351:1-hydroxy-2-oxo-3,3-bis(2-aminoethyl)-1-triazene; D004791:Enzyme Inhibitors; D020030:Nitric Oxide Donors; D014226:Triazenes; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D006152:Cyclic GMP; D019331:NG-Nitroarginine Methyl Ester