RT Journal Article
SR Electronic
T1 Rheology of mucus and transepithelial potential difference: small airways versus trachea
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 67
OP 75
DO 10.1183/09031936.93.06010067
VO 6
IS 1
A1 EM App
A1 JG Zayas
A1 M King
YR 1993
UL http://erj.ersjournals.com/content/6/1/67.abstract
AB The transfer of water across the airway epithelium is closely related to the transepithelial potential difference (PD). Thus, PD should be directly involved in the regulation of airway intraluminal water content and, by extension, mucus rheology. Experiments by Boucher and co-workers (J Appl Physiol, 1980; 48: 169; and 1981; 51: 706) indicated that the values of PD in the small airways of dogs were considerably lower than in the trachea or mainstem bronchus. This fact suggests that water is increasingly removed from the airway lumen in the cephalad direction, and provides a possible mechanism whereby airway flooding is avoided as the total airway cross-section diminishes mouthward. We investigated this possibility by collecting and analysing mucus from the small airways and trachea of anaesthetized dogs and comparing our findings with measurements of PD. Mucus was collected on a cytology brush placed against the wall of the airway. Tracheal samples were taken from the lower lateral or anterior trachea, while small airway samples were taken from a 6th or 7th generation bronchus, chosen at random from either side. Measurements of PD were made at comparable sites. The mucus was analysed for its viscoelastic properties using the magnetic microrheometer technique. PD in the 6th-7th generation bronchus was significantly less than in the lower trachea (4.1 +/- 1.3 vs 17.2 +/- 7.1 mV). The rigidity of mucus collected from the small airways (log mechanical impedance (G*) at 100 rad.s-1) was significantly less than in the trachea (2.81 +/- 0.22 vs 3.01 +/- 0.29).(ABSTRACT TRUNCATED AT 250 WORDS)