Bovine bronchial epithelial cells metabolize L-arginine to L-citrulline: possible role of nitric oxide synthase.
The conversion of L-arginine to L-citrulline is catalyzed by nitric oxide synthase (NOS), and results in the release of nitric oxide (NO). We hypothesized that bronchial epithelial cells metabolize L-arginine to L-citrulline. We found that cell lysates obtained from unstimulated, cultured bovine bronchial epithelial cells (BBECs) converted L-[3H]arginine to L-[3H]citrulline. This conversion was attenuated by three competitive NOS inhibitors and modulated by lipopolysaccharide and cigarette smoke extract (p < 0.01, all comparisons). These data demonstrate that BBECs metabolize L-arginine to L-citrulline and implicate a role for the L-arginine:NOS biosynthetic pathway in modulating airway responses.
Robbins
R A
RA
Research Service, Omaha DVA Medical Center, Nebraska.
Hamel
F G
FG
Floreani
A A
AA
Gossman
G L
GL
Nelson
K J
KJ
Belenky
S
S
Rubinstein
I
I
D000594:Amino Acid Oxidoreductases / Q000378:metabolism*; D000818:Animals; D001120:Arginine / Q000378:metabolism*; D001980:Bronchi / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D002956:Citrulline / Q000378:metabolism*; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase; D012906:Smoke
D008070:Lipopolysaccharides; D012906:Smoke; D002956:Citrulline; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases