We measured the rate of fluid movement across the tracheal epithelium of the dog by an electrical method, modified from that originally described by Wiedner (Rev. Sci. Instrum. 47: 775-6, 1976). These base-line volume flow (J(v) from the submucosa to the mucosa was 44 ± 23 nl·min-1·cm-2 (mean ± SE; n = 6). In only three of the tissues was the resting J(v) significantly greater than zero. Stimulation with 2 x 10-3 M aminophylline (a drug that we have shown stimulates Cl secretion under short-circuit conditions) increased J(v) in all tissues to a mean of 137 ± 29 nl·min-1·cm-2 (P < 0.001). We also measured the unidirectional fluxes of Cl with the tissue at its spontaneous electrical potential. During the base-line period, the net flux of Cl was not significantly different from zero. During stimulation with aminophylline, Cl secretion increased to a mean of 1.44 ± 0.50 μeq·cm-2·h-1. Comparison of the stimulated values of J(v) and net Cl secretion suggest that fluid secretion by the trachea is isotonic during stimulation with aminophylline.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of Applied Physiology Respiratory Environmental and Exercise Physiology|
|State||Published - 1980|
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