[Increased production of nitric oxide in the immediate and late asthmatic responses in guinea pigs].
The nitric oxide (NO) levels in exhaled air and the population of nitric oxide synthase (NOS) synthesizing epithelium in airways are reported to be increased in patients with asthma. NO may be implicated in the pathophysiology of asthma. In this study, we examined the inducible NOS (iNOS) mRNA levels in the lung of a guinea pig model of experimental asthma which exhibits both the immediate and late asthmatic responses (IAR/LAR), following challenge with antigen, using the methods of Northern blot analysis. After challenge with antigen, iNOS mRNA were increased in a time-dependent manner (before challenged < IAR < LAR). Furthermore, we estimated NO productions in the trachea using bioassay by 5-HT-induced tracheal smooth muscle relaxation which are involved in NO. The 5-HT-induced relaxations were accelerated in a time-dependent manner after challenge with antigen, reflecting increased NO production (before challenged < IAR < LAR). These observations suggest that NO would be involved in the pathophysiology of asthma.
Uchida
Y
Y
Department of Pulmonary Medicine, University of Tsukuba.
Hasegawa
S
S
D000818:Animals; D001249:Asthma / Q000201:enzymology*; D004195:Disease Models, Animal; D005260:Female; D006168:Guinea Pigs; D008168:Lung / Q000201:enzymology*; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis*
D009569:Nitric Oxide; D019001:Nitric Oxide Synthase