Lack of inhibitory effect of dexamethasone on exhalation of nitric oxide by healthy humans.
Nitric oxide (NO) is present in the breath exhaled from healthy humans. The location and subtype of the NO synthase responsible for the expired NO are unknown. As dexamethasone inhibits the induction of NO synthase, we evaluated the effect of administering dexamethasone (4 mg/day for 2 days) on the amount of NO exhaled by eight healthy men. The amount of NO showed a significant linear correlation with the duration of exhalation, allowing the rate of NO release to be calculated. The rate of NO release was 0.047 +/- 0.023 nmol/s before drug administration. There was no significant change in the release rate at the end of the 2-day administration of drug or at 5 days after cessation. Serum concentrations of interferon-gamma and interleukin-1 beta were unaffected by the administration of dexamethasone. These results suggest that the NO released from the human airway under normal conditions is not generated by the action of inducible NO synthase.
Sato
K
K
Second Department of Internal Medicine, Gunma University School of Medicine, Maebashi.
Sumino
H
H
Sakamaki
T
T
Sakamoto
H
H
Nakamura
T
T
Ono
Z
Z
Nagai
R
R
D000328:Adult; D001944:Breath Tests; D003907:Dexamethasone / Q000494:pharmacology*; D004790:Enzyme Induction / Q000187:drug effects; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007371:Interferon-gamma / Q000097:blood; D007375:Interleukin-1 / Q000097:blood; D008297:Male; D009569:Nitric Oxide / Q000032:analysis / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D018384:Oxidative Stress; D012016:Reference Values; D012137:Respiratory System / Q000201:enzymology
D007375:Interleukin-1; D009569:Nitric Oxide; D003907:Dexamethasone; D007371:Interferon-gamma; D019001:Nitric Oxide Synthase; D006854:Hydrocortisone