- Paper Report
- Open Access
Airway surface liquid composition in mice
- Christina Haston1
© Biomed Central Ltd 2001
- Received: 12 September 2000
- Accepted: 19 September 2001
- Published: 19 September 2001
- Airway surface liquid, cystic fibrosis
One hypothesis linking mutations in CFTR with lung disease suggests that the airway surface liquid in the lung of CF patients is altered due to the defective (CFTR) epithelial chloride channel. This altered liquid has been proposed to effect the antibacterial properties of the lung, or the viscosity of the mucus, leading to the perpetual lung infections which ultimately limit survival in most CF patients. The ionic composition of the airway surface liquid was measured in different inbred strains of mice and in knockout mice lacking functional CFTR (CF mice).
SL sampling: anaesthetized mice (C57BL/6, A/J, BALB/c, B6-Cftr UNC-/-) were tracheotomized and a sampling capillary (PE-10 tubing) was inserted into the trachea so that its end lay in contact with the epithelium at the base of the trachea
The sample was collected for 30 min (volume collected = 100/200 nL) and analysed by capillary electrophoresis
Submucosal gland distribution was assessed through image analysis of histological sections
The concentrations of sodium and chloride ions were significantly lower in the ASL than they were in plasma, as in other studies including ones using humans. The ASL ionic composition in five B6 CF mice was similar to their littermate controls (n = 25). Inbred mouse strain differences in the amount of ASL that could be harvested were reported, and attributed to differences in submucosal gland distribution among the strains.
The authors reiterate that ASL collection in this small animal is challenging, and despite imperfect data, the results agree with the studies in other species. The principal finding presented is that murine ASL has a lower salinity than plasma. In a limited study, the ASL of CF mice was found to not differ from that of wild-type littermates. The ionic concentration of potassium in the ASL of mice differs from previous reports in rats, which is attributed to species or sample collection differences.