Differential effect of epidermal growth factor on serous and mucous cells in porcine airway submucosal gland.
Using a patch-clamp technique, we found that the fresh porcine submucosal gland acinar cells contained two functionally distinct cell populations, i.e. physiologically relevant concentration of acetylcholine (ACh, 30 nM) induced two distinct patterns of electric response in tracheal gland acinar cells. One was characterized by an outstanding oscillatory Cl(-)-current activity, and the other was with poor Cl(-)-current response but with a comparable K(+)-current. We examined the effect of epidermal growth factor (EGF) on the ACh-induced electric responses in these cells. EGF affected only the latter (K(+)-prominent) cell type to potentiate significantly the ACh-induced K(+)-current. An immunohistochemistry revealed that the receptor for EGF was identified preferentially on the mucous, but not serous, cells. Genistein, one of the tyrosine-kinase inhibitors, abolished the augmentation effect of EGF on the ACh-induced current. Thus, we identified the serous cell with a Cl(-)-rich current in response to ACh and the mucous cell with a K(+)-dominant response. Moreover, EGF affected the mucous cells alone to potentiate the ACh-induced electric response. EGF may contribute to the pathophysiological alterations in chronic inflammatory airways both in morphological (mucous cell hypertrophy/hyperplasia) and functional (thick viscous hypersecretion) ways.
Iwase
Nobuhisa
N
The First Department of Internal Medicine, Tohoku University Graduate School of Medicine, 1-1, Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.
Sasaki
Tsukasa
T
Oshiro
Takako
T
Tamada
Tsutomu
T
Nara
Masayuki
M
Sasamori
Kan
K
Hattori
Toshio
T
Shirato
Kunio
K
Maruyama
Yoshio
Y
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004553:Electric Conductivity; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066246:ErbB Receptors / Q000378:metabolism; D005088:Exocrine Glands / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D019833:Genistein / Q000494:pharmacology; D007150:Immunohistochemistry; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009093:Mucus / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D018408:Patch-Clamp Techniques / Q000379:methods; D026902:Potassium Channel Blockers / Q000494:pharmacology; D013552:Swine; D019789:Tetraethylammonium / Q000494:pharmacology; D014132:Trachea / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology; D062367:ortho-Aminobenzoates / Q000494:pharmacology
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D004791:Enzyme Inhibitors; D026902:Potassium Channel Blockers; D014665:Vasodilator Agents; D062367:ortho-Aminobenzoates; D004815:Epidermal Growth Factor; D019789:Tetraethylammonium; C001209:fenamic acid; D019833:Genistein; D066246:ErbB Receptors; D000109:Acetylcholine