Soukhova G K, Ahmed M, Fletcher E C, Yu J
Pulmonary Division, Department of Medicine, University of Louisville, Louisville, KY 40292, USA.
Chest. 1999 Nov;116(5):1365-8. doi: 10.1378/chest.116.5.1365.
To elucidate the mechanism of hyperpnea and tachypnea, which are the common findings in cardiopulmonary patients.
Recently, it was found that activating pulmonary afferents by directly injecting hypertonic saline solution into the lung periphery causes a vagally mediated neural hyperpnea and tachypnea, ie, the excitatory lung reflex. Since reactive oxygen species are released during a variety of pulmonary diseases, we examined whether hydrogen peroxide (H(2)O(2)), a common mediator in cardiopulmonary diseases, can initiate the same excitatory lung reflex.
We recorded phrenic efferent activity in anesthetized, open chest, artificially ventilated rabbits as an index of respiratory drive and examined the respiratory responses to injections of H(2)O(2) (10 micromol in 0.1 mL). The responses were compared with those to hypertonic saline solution (8.1%, 0.1 mL). H(2)O(2) and hypertonic saline solution increased both the rate (mean [+/- SEM], 43 +/- 8% and 61 +/- 10%, respectively; n = 30; p = 0.001) and the amplitude of phrenic bursts (12 +/- 2% and 20 +/- 4%, respectively; n = 30; p = 0.033). These responses were abolished by bilateral vagotomy.
H(2)O(2) can initiate the excitatory lung reflex. Therefore, mediator(s) released in pulmonary diseases could be one of the mechanisms causing hyperpnea and tachypnea.
阐明呼吸急促和呼吸过速的机制，这是心肺疾病患者的常见表现。
最近发现，通过向肺周边直接注射高渗盐溶液激活肺传入神经会引发迷走神经介导的神经性呼吸急促和呼吸过速，即兴奋性肺反射。由于在多种肺部疾病中会释放活性氧，我们研究了过氧化氢（H₂O₂），一种心肺疾病中的常见介质，是否能引发相同的兴奋性肺反射。
我们记录了麻醉、开胸、人工通气兔的膈传出活动，作为呼吸驱动的指标，并研究了对注射H₂O₂（0.1 mL中含10 μmol）的呼吸反应。将这些反应与对高渗盐溶液（8.1%，0.1 mL）的反应进行比较。H₂O₂和高渗盐溶液均增加了膈神经冲动的频率（平均值[±标准误]分别为43±8%和61±10%；n = 30；p = 0.001）和幅度（分别为12±2%和20±4%；n = 30；p = 0.033）。双侧迷走神经切断术消除了这些反应。
H₂O₂可引发兴奋性肺反射。因此，肺部疾病中释放的介质可能是导致呼吸急促和呼吸过速的机制之一。
