Galanin and somatostatin inhibition of substance P-induced airway mucus secretion in the rat.
Substance P is present in several neurons innervating the lung. Tachykinin receptors are expressed on submucosal gland cells. Substance P is known to be a potent stimulator of airway mucus secretion. In the present study we characterized the effects of galanin and somatostatin on basal and substance P-induced mucus secretion. The stimulatory effect of substance P was concentration-dependent (100 pmol/l: 112%, 1 nmol/l: 120%, 10 nmol/l: 153%, 100 nmol/l: 223%, 1 mumol/l: 275%, 10 mumol/l: 172%) and was inhibited by galanin and somatostatin (1 mumol/l substance P: 277%; 1 mumol/l substance P + 1 mumol/l somatostatin: 190%, p < 0.01; 1 mumol/l substance P + 1 mumol/l galanin: 206%, p < 0.05). In the presence of lower concentrations of substance P 1 mumol/l somatostatin and 1 mumol/l galanin did not modify mucus secretion. Lower concentrations of galanin and somatostatin did not significantly change mucus secretion stimulated by 1 mumol/l substance P. Both, galanin and somatostatin at 1 mumol/l left basal airway mucus secretion unaltered. These data suggest that mucus secretion into airways is regulated by a complex network of peptidergic stimulators and inhibitors including substance P, somatostatin and galanin.
Wagner
U
U
Department of Internal Medicine, Philipps-University of Marburg, Germany.
Fehmann
H C
HC
Bredenbröker
D
D
Yu
F
F
Barth
P J
PJ
von Wichert
P
P
D000818:Animals; D004305:Dose-Response Relationship, Drug; D019004:Galanin; D008168:Lung / Q000502:physiology; D008297:Male; D009093:Mucus / Q000378:metabolism*; D010455:Peptides / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013004:Somatostatin / Q000494:pharmacology*; D013373:Substance P / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D014132:Trachea / Q000502:physiology
D010455:Peptides; D013373:Substance P; D013004:Somatostatin; D019004:Galanin