June 1, 2002
View Full PaperIn vivo microdialysis for determination of nasal liquid ion composition
Key Points
- The study aims to determine the ion composition of nasal liquid in a cystic fibrosis mouse model compared to normal mice.
- Used in vivo microdialysis to sample nasal liquid without removing volume.
- Incorporated potential difference electrode to assess airway integrity.
- Compared ion concentrations of sodium, chloride, and potassium in cystic fibrosis and normal mice.
- Nasal liquid sodium levels were 111 mM in cystic fibrosis and 107 mM in normal mice, not significantly different.
- Chloride levels were 122 mM in cystic fibrosis and 120 mM in normal mice, also not significantly different.
- Potassium levels were significantly higher in cystic fibrosis mice (16.6 mM) compared to normal mice (8.7 mM).
Abstract
Airway surface liquid (ASL) contains substances important in mucociliary clearance and airway defense. Little is known about substance concentrations in ASL because of its small volume and sampling difficulties. We used in vivo microdialysis (IVMD) to sample liquid lining the nasal cavity without net volume removal and incorporated into IVMD a potential difference (PD) electrode to assess airway integrity. The cystic fibrosis (CF) mouse nasal epithelia exhibit ion transport defects identical to those in CF human airways and, thus, are a good model for CF disease. We determined that nasal liquid Na+ (107 +/- 4 mM normal; 111 +/- 9 mM CF) and Cl- (120 +/- 6 mM normal; 122 +/- 4 mM CF) did not differ between genotypes. The nasal liquid K+ (8.7 +/- 0.4 mM) was significantly less in normal than in CF mice (16.6 +/- 4 mM). IVMD accurately samples nasal liquid for ionic composition. The ionic composition of nasal liquid in the normal and CF mice is similar.