Clerici C, Harf A, Gaultier C, Roudot F
Département de Physiologie, Faculté de Médecine, Créteil, France.
J Appl Physiol (1985). 1989 May;66(5):2145-9. doi: 10.1152/jappl.1989.66.5.2145.
The magnitude of parasympathetic reflex-mediated bronchoconstriction during histamine infusion was compared in anesthetized paralyzed newborn and adult guinea pigs. The animals were ventilated using a constant-flow ventilator, and the conductance and compliance of the respiratory system were continuously monitored. We found that reactivity to histamine infusion was less in newborns than in adults, because newborns required a larger dose of histamine than adults (300 vs. 125 ng.kg-1.s-1) to produce an equivalent decrease in conductance (42 +/- 13 vs. 42 +/- 15%). Vagal interruption by bilateral cervical vagotomy or muscarinic blockade with atropine (3 mg/kg) significantly reduced the bronchoconstrictor response to histamine in adults. By contrast, neither vagotomy nor atropine significantly changed this response in the newborns. These results indicate the lack of a vagal component in the bronchoconstriction that histamine induced in the newborns. Their relative unresponsiveness to histamine might partly be related to the fact that, in the newborn, histamine mainly acts directly via its airway receptors.
在麻醉并麻痹的新生豚鼠和成年豚鼠中，比较了组胺输注期间副交感神经反射介导的支气管收缩程度。使用恒流呼吸机对动物进行通气，并持续监测呼吸系统的传导率和顺应性。我们发现，新生豚鼠对组胺输注的反应性低于成年豚鼠，因为新生豚鼠产生等效传导率下降（42±13%对42±15%）所需的组胺剂量大于成年豚鼠（300对125 ng·kg-1·s-1）。双侧颈迷走神经切断术或用阿托品（3 mg/kg）进行毒蕈碱阻断对成年豚鼠迷走神经的干扰显著降低了对组胺的支气管收缩反应。相比之下，迷走神经切断术和阿托品均未显著改变新生豚鼠的这种反应。这些结果表明，组胺在新生豚鼠中诱导的支气管收缩缺乏迷走神经成分。它们对组胺相对无反应可能部分与以下事实有关，即在新生豚鼠中，组胺主要通过其气道受体直接起作用。
