Nitric oxide modulation of Ca2+ responses in cow tracheal epithelium.
Nitric oxide (NO) plays an important role in the regulation of Ca2+ -dependent airway epithelial function such as ciliary motility. In this experiment, the effect of NO on intracellular Ca2+ ([Ca2+]1) was studied in cultured cow tracheal epithelium by the fura-2 method. L-NG-nitroarginine methyl ester, an NO synthase inhibitor, per se did not significantly alter baseline [Ca2-]i, but bradykinin- and ATP-induced increases in [Ca2+]i were significantly reduced in the presence of L-NG-nitroarginine methyl ester. This inhibitory effect disappeared by a simultaneous addition of L-arginine. Sodium nitroprusside or dibutyryl cyclic GMP potentiated bradykinin- and ATP-induced increases in [Ca2+]i. Cytochemistry for NADPH diaphorase activity revealed the presence of NO synthase in the cultured epithelium. These results suggest that NO produced by NO synthase in airway epithelium modulates bradykinin- and ATP-induced [Ca2+]i responses, which may be dependent on cyclic GMP.
Sakai
A
A
First Department of Medicine, Tokyo Women's Medical College, Japan.
Kondo
M
M
Tamaoki
J
J
Konno
K
K
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D001920:Bradykinin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D004848:Epithelium / Q000187:drug effects; D066298:In Vitro Techniques; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D014132:Trachea / Q000187:drug effects*; D019323:omega-N-Methylarginine
D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D000255:Adenosine Triphosphate; D001120:Arginine; D019001:Nitric Oxide Synthase; D001920:Bradykinin; D002118:Calcium; D019331:NG-Nitroarginine Methyl Ester