Matera M G, Imperatore F, D'Agostino B, Amorena M, Luongo C, Mangoni G, Scafuro M A, Portolano F, Rossi F
Institute of Pharmacology and Toxicology, Faculty of Medicine, 2nd University of Naples, Italy.
Res Commun Mol Pathol Pharmacol. 1997 Jan;95(1):105-8.
The effects of prolonged (20 day) hyperbaric exposure (HBO) to oxygen on non adrenergic non cholinergic (NANC) contractile and relaxant responses of rat trachea were examined. The electrical field stimulation (EFS) of rat tracheal rings was performed at 30 Hz and contractile and relaxant responses were assessed in the absence or in the presence of pretreatment with L-nitro-arginine-methyl-ester (L-NAME), an inhibitor of NO synthase, and L-Arginine (L-ARG), a precursor of NO synthesis, plus L-NAME. Our data demonstrated that L-NAME significantly (p < 0.05) enhanced the contractile responses induced by EFS (controls 30.6 +/- 0.99%; L-NAME 76.07 +/- 2.00%) and statistically (p < 0.05) reduced the relaxant component of EFS (controls 31.10 +/- 0.46; L-NAME 15.00 +/- 0.12); these effects were reversed when tissues were pretreated with L-ARG plus L-NAME, suggesting that NO plays a modulatory role in cholinergic neurotransmission and participates in EFS relaxant responses. Moreover, prolonged HBO exposure (20 days) at 202.6 and 303.9 kPa did not modify the contractile or relaxant responses induced by EFS, nor modify the L-NAME or L-ARG effects on EFS responses.
研究了长时间（20天）高压氧暴露（HBO）对大鼠气管非肾上腺素能非胆碱能（NANC）收缩和舒张反应的影响。以30Hz频率对大鼠气管环进行电场刺激（EFS），并在不存在或存在一氧化氮合酶抑制剂L-硝基精氨酸甲酯（L-NAME）以及一氧化氮合成前体L-精氨酸（L-ARG）加L-NAME预处理的情况下评估收缩和舒张反应。我们的数据表明，L-NAME显著（p<0.05）增强了EFS诱导的收缩反应（对照组30.6±0.99%；L-NAME组76.07±2.00%），并在统计学上（p<0.05）降低了EFS的舒张成分（对照组31.10±0.46；L-NAME组15.00±0.12）；当组织用L-ARG加L-NAME预处理时，这些效应被逆转，表明一氧化氮在胆碱能神经传递中起调节作用并参与EFS舒张反应。此外，在202.6和303.9kPa下长时间（20天）HBO暴露并未改变EFS诱导的收缩或舒张反应，也未改变L-NAME或L-ARG对EFS反应的影响。
