Journal of Applied Physiology, Vol 66, Issue 2 764-770, Copyright © 1989 by American Physiological Society
Effect of epithelium on mucus secretion from feline tracheal submucosal glands
T. Sasaki, S. Shimura, H. Sasaki and T. Takishima
First Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan.
We studied the effect of airway epithelium on mucus secretion by use of an
isolated tracheal submucosal gland preparation reported previously (J.
Appl. Physiol. 60: 1237-1247, 1986). Mucus glycoconjugate release from
submucosal glands of feline trachea was examined using [3H]glucosamine as a
mucus precursor. Isolated glands showed significantly higher secretory
responses to cholinergic, alpha-, and beta-adrenergic agonists and
dibutyryladenosine 3',5'-cyclic monophosphate (average 400% of control)
than the conventional tracheal mucosal explants, which contained epithelium
and submucosal tissues in addition to submucosal glands (average 160% of
control). The addition of isolated epithelium depressed the secretory
response of isolated glands to the same level as that of tracheal explants.
However, the supernatant from isolated epithelium failed to inhibit
secretory responses to methacholine in isolated glands, suggesting that the
epithelium-derived inhibitory factor to secretion may be short-lived.
Leukotriene D4 antagonist (FPL 55712), cyclooxygenase and/or lipoxygenase
inhibitors (indomethacin or BW 755C) caused no significant change in the
inhibitory action of epithelium, suggesting that the inhibition is not due
to arachidonic acid metabolites. The newly found secretory inhibitory
action of epithelium is of particular interest in the pathogenesis of
hypersecretion associated with epithelial damage.
