Respiratory pattern and hypoxic ventilatory response in mice functionally lacking alpha2A-adrenergic receptors.
Respiratory pattern and hypoxic ventilatory response in mice functionally lacking alpha2A-adrenergic receptors.
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功能性缺乏 α2A 肾上腺素受体的小鼠的呼吸模式和缺氧通气反应。
DOI：
10.1007/978-1-4615-1375-9_31
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发表时间：
2001
影响因子：
--
通讯作者：
MacMillan,LB
中科院分区：
文献类型：
--
作者：
Bissonnette,JM;Knopp,SJ;Wright,DM;MacMillan,LB
新生哺乳动物（包括人类）的呼吸模式在新生期发生变化10，11，26，27，36。这些发育变化的特征是吸气时间（TI）持续时间的增加，这在相对较短的妊娠后出生的物种（如负鼠10和小鼠27）中可能非常明显。除了代谢、肺力学和来自外周的刺激输入的发育差异外，吸气神经元的固有膜特性可能有助于TI的延长。早在出生后第1天（P1），大鼠舌下神经运动神经元35和位于前Bötzinger复合体（PBC）28的小鼠吸气神经元中就存在尖峰频率适应和后超极化。通过高电压激活（HVA）钙通道的钙进入已被证明是PBC神经元9、孤束腹侧核29和舌下运动神经元32，33中通过激活慢传导钙激活钾通道29，34产生AHP所必需的。因此，发育过程中HVA钙通道的抑制性调节是TI延长的潜在机制。α 2a肾上腺素能受体通过百日咳毒素敏感性G蛋白与各种效应物偶联，包括抑制电压激活的Ca2+通道20，并已在髓质的心肺区域中得到证实1，31，是该作用的候选者。为了评价其重要性，在功能上缺乏α 2a肾上腺素能受体的小鼠中检查了出生后呼吸时间。
In newborn mammals including man the respiratory pattern undergoes changes during the neonatal period10, 11, 26, 27, 36.These developmental changes are characterized by an increase in the duration of inspiratory time (TI), which in species born after relatively short gestations such as opossum10and mouse27can be quite marked. In addition to developmental differences in metabolism, pulmonary mechanics and stimulatory input from the periphery the intrinsic membrane properties of inspiratory neurons may contribute to this lengthening of TI. Spike frequency adaptation and afterhyperpolarization is present as early as postnatal day 1 (P1) in rat hypoglossal motoneurons35and PO in mouse inspiratory neurons located in the pre-Bötzinger complex (PBC)28. Entry of calcium through high-voltage-activated (HVA) calcium channels has been shown to be essential for the generation of the AHP in PBC neurons9, ventral nucleus of the solitary tract29and hypoglossal motoneurons32, 33by activating slow-conductance calcium-activated potassium channels29,34. Therefore, the inhibiting modulation of HVA calcium channels during development is a potential mechanism by which TI could be prolonged. α2aadrenergic receptors which are coupled by pertussis toxin sensitive G proteins to various effectors, including inhibition of voltage activated Ca2+channels20, and have been demonstrated in cardiorespiratory areas of the medulla1, 31are candidates for this role. In order to evaluate their importance respiratory timing in the postnatal period was examined in mice who functionally lack α2aadrenergic receptors.