Influence of in vitro radiation on changes in nitric oxide in rat macrophages and smooth muscle cells.
We examined changes in nitric oxide (NO) levels resulting from irradiation of rat macrophage (RAM) and smooth muscle cells (SMC) in medium. Irradiation did not alter the NO concentration in the medium of either cell line. However, irradiation of 5 and 20 Gy enhanced the concentration of NO induced by lipopolysaccharide (LPS) in the medium containing RAM. Furthermore, 20 Gy of irradiation suppressed NO production induced by interferon-gamma in the RAM medium. Radiation seemed to enhance NO production more than that caused by Interleukin 1-beta only in the medium containing SMC. Next, mRNA levels of inducible NO synthase (NOS) were examined in RAM by Northern blotting following irradiation. Five Gy of irradiation did not generate iNOS mRNA expression, but did enhance iNOS piRNA expression induced by LPS, while 20 Gy suppressed the expression level of iNOS mRNA more than 5 Gy. This leads to the conclusion that radiation stimulation induced NO production through indirect action on the macrophage.
Koizumi
Masahiko
M
Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
Yamazaki
Hideya
H
Toyokawa
Kazushige
K
Ozeki
Shuji
S
Matsumura
Satoko
S
Inoue
Takehiro
T
Inoue
Toshihiko
T
D000818:Animals; D002460:Cell Line; D004307:Dose-Response Relationship, Radiation; D007371:Interferon-gamma / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D016676:Macrophages, Alveolar / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D051379:Mice; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis / Q000235:genetics; D052247:Nitric Oxide Synthase Type II; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats
D008070:Lipopolysaccharides; D012333:RNA, Messenger; D009569:Nitric Oxide; D007371:Interferon-gamma; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C496318:Nos2 protein, rat