Koyama S, Ohtsuka A, Horie T
First Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan.
Tohoku J Exp Med. 1992 Dec;168(4):611-9. doi: 10.1620/tjem.168.611.
We examined whether eucapnic hyperventilation with dry air produces the bronchoconstriction in anesthetized, non-sensitized rabbits and in ovalbumin sensitized rabbits. Eucapnic hyperventilation challenge with dry air containing 5% CO2 at room temperature was performed with 4 non-sensitized and 7 sensitized rabbits by mechanical ventilation for 15 min (120 breaths/min, 7 ml tidal volume/kg body weight). Total lung resistance (RL) and dynamic compliance (Cdyn) were measured before and 0, 5, 15, and 30 min after hyperventilation. In non-sensitized rabbits, RL and Cdyn did not change significantly. However, in sensitized rabbits, RL increased maximally by 48.9% +/- 9.0% at 5 min, and then decreased to the baseline level at 30 min after challenge. Cdyn decreased maximally by 12.5% +/- 3.5% at 15 min after challenge. These changes were significantly different from the baselines (p < 0.05). Furthermore, to investigate the role of histamine on hyperventilation-induced bronchoconstriction (HIB) in sensitized rabbits, we performed the hyperventilation challenges in 5 sensitized rabbits with the pretreatment of H1-receptor antagonist (chlorpheniramine, 1 mg/kg, i.v.) and found that the maximum increment of RL was suppressed to 24.2% +/- 7.4% of the control, which was significantly lower than the maximal RL in nontreated sensitized rabbits (p < 0.05). We concluded that HIB occurs only in sensitized rabbits and that histamine may play an important role in the development of HIB in sensitized rabbits.
我们研究了在麻醉的、未致敏的兔子以及卵清蛋白致敏的兔子中，吸入干燥空气进行等碳酸过度通气是否会引起支气管收缩。对4只未致敏兔子和7只致敏兔子进行机械通气，在室温下用含5%二氧化碳的干燥空气进行等碳酸过度通气激发试验15分钟（120次呼吸/分钟，潮气量7毫升/千克体重）。在过度通气前以及过度通气后0、5、15和30分钟测量总肺阻力（RL）和动态顺应性（Cdyn）。在未致敏兔子中，RL和Cdyn没有显著变化。然而，在致敏兔子中，RL在5分钟时最大增加48.9%±9.0%，然后在激发后30分钟降至基线水平。Cdyn在激发后15分钟时最大下降12.5%±3.5%。这些变化与基线相比有显著差异（p<0.05）。此外，为了研究组胺在致敏兔子过度通气诱导的支气管收缩（HIB）中的作用，我们对5只致敏兔子进行了H1受体拮抗剂（氯苯那敏，1毫克/千克，静脉注射）预处理后再进行过度通气激发试验，发现RL的最大增量被抑制至对照组的24.2%±7.4%，这显著低于未治疗的致敏兔子的最大RL（p<0.05）。我们得出结论，HIB仅发生在致敏兔子中，并且组胺可能在致敏兔子HIB的发生中起重要作用。
