Stimulation of Cl secretion by lactoferrin across canine airway epithelial cells in culture.
To investigate the effect of lactoferrin, an iron-binding glycoprotein in the respiratory tract, on ion transport function of airway epithelial cells, we measured bioelectric properties of canine cultured tracheal epithelium by Ussing's short-circuit technique. Addition of lactoferrin (60 micrograms/ml) to the mucosal side of epithelial sheet increased the short-circuit current (Isc) from 4.8 +/- 0.8 to 7.5 +/- 1.1 microA/cm2, and the submucosal addition likewise increased Isc from 3.8 +/- 0.6 to 5.6 +/- 0.7 microA/cm2 (p < 0.001, in each case). This effect was concentration dependent. The lactoferrin-induced increase in Isc was not altered by amiloride, indomethacin, or propranolol but was abolished by diphenylamine-2-carboxylate or substitution of Cl with iodide in the medium. Intracellular cyclic AMP levels were not increased by lactoferrin. These results suggest that lactoferrin may selectively stimulate Cl secretion across the airway mucosa, an effect that may not be dependent on prostaglandins, beta-adrenergic receptor or intracellular cyclic AMP.
Chiyotani
A
A
First Department of Medicine, Tokyo Women's Medical College, Japan.
Tamaoki
J
J
Yamauchi
F
F
Takeuchi
S
S
Kanemura
T
T
Konno
K
K
D000818:Animals; D001693:Biological Transport, Active; D002478:Cells, Cultured; D002712:Chlorides / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D004285:Dogs; D004848:Epithelium / Q000378:metabolism; D005260:Female; D017136:Ion Transport / Q000187:drug effects / Q000502:physiology; D007781:Lactoferrin / Q000493:pharmacokinetics / Q000494:pharmacology*; D008297:Male; D009079:Mucociliary Clearance; D014132:Trachea / Q000166:cytology / Q000378:metabolism*
D002712:Chlorides; D000242:Cyclic AMP; D007781:Lactoferrin