Nitric oxide production by polymorphonuclear leukocytes in sputum from cystic fibrosis patients with chronic lung infection

Research output: Contribution to journalConference abstract in journalResearch

Objective: Chronic Pseudomonas aeruginosa lung infection in CF patients is characterized by persisting mucoid biofilm in hypoxic endobronchial mucus. These biofilms are surrounded by numerous polymorphonuclear leukocytes (PMNs), which are the major consumers of O2 for production of O2-. In this study, we hypothesized that nitric oxide (NO) is also produced by the NO synthases (NOS) in the O2 consuming PMNs in the endobronchial mucus.

Methods and results: This hypothesis was tested on fresh expectorated sputum from chronically infected CF patients by estimating and visualizing the NO production. A possitive correlation was observed between active PMNs and stable endproducts of NO production; NO3- and NO2- (P< 0.04, r2: 0.66, n = 10, P< 0.006, r2: 0.78, n = 11) using the Griess Reagent System, indicating a production of NO by PMNs. In addition, microsensor analysis revealed the presence of discrete occurrences of NO. By fluorescence microscopy PMNs stained with the NO-indicator, DAF-FM, could be identified. To further verify NO production by the PMNs, active NOS in CF sputum is presently beeing substantiated by estimating O2 consumption and DAF-FM fluorescence during inhibition of NOS.

Conclusions: The present study suggests that besides consumption of O2 for O2- production, the PMNs in CF sputum can also consume O2 for NO production. Therefore in addition to consume O2 for the production of reactive oxygen species, the PMNs in CF sputum are also capable of consuming O2 for the generation of reactive nitrogen species.
Original languageEnglish
JournalJournal of Cystic Fibrosis
Issue numberSupplement 1
Pages (from-to)S49
Number of pages1
Publication statusPublished - 2010
Event33rd European Cystic Fibrosis Conference 2010 - Valencia, Spain
Duration: 19 May 201016 Jun 2010
Conference number: 33


Conference33rd European Cystic Fibrosis Conference 2010

ID: 19794379