CGRP induces [Ca2+]i rise and glycoconjugate secretion in feline tracheal submucosal gland.
Submucosal glands were isolated from feline trachea. The intracellular Ca2+ concentration ([Ca2+]i) of the acinar cells of isolated glands was measured using the fluorescent dye Fura-2. Calcitonin gene-related peptide (CGRP) at 10(-8) to 10(-5) M produced a significant and sustained rise in the [Ca2+]i of isolated glands, reaching a maximal response of 127% of the prior baseline level but did not alter the intracellular adenosine 3', 5'-cyclic monophosphate ([cAMP]i). In a Ca(2+)-free solution, CGRP produced no significant alteration in [Ca++]i. Glycoconjugate secretion from isolated glands was stimulated by CGRP in a dose dependent fashion, reaching a maximal response of 167% of control at 10(-6) M but was without effect in tracheal explants. Further, CGRP did not produce any significant increase in glycoconjugate secretion in the Ca(2+)-free medium. These findings indicate that CGRP stimulates glycoconjugate secretion from airway submucosal glands by inducing Ca2+ influx from the extracellular solution.
Nagaki
M
M
First Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan.
Sasaki
T
T
Shimura
S
S
Satoh
M
M
Takishima
T
T
Shirato
K
K
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002415:Cats; D000242:Cyclic AMP / Q000378:metabolism; D006001:Glycoconjugates / Q000378:metabolism*; D066298:In Vitro Techniques; D007425:Intracellular Membranes / Q000378:metabolism*; D009092:Mucous Membrane / Q000378:metabolism; D009994:Osmolar Concentration; D014132:Trachea / Q000378:metabolism*
D006001:Glycoconjugates; D000242:Cyclic AMP; D015740:Calcitonin Gene-Related Peptide; D002118:Calcium