Chemosensitivity of sympathoexcitatory neurones in the rostroventrolateral medulla of the cat
Chemosensitivity of sympathoexcitatory neurones in the rostroventrolateral medulla of the cat
复制标题
猫延髓头腹外侧交感兴奋神经元的化疗敏感性
DOI：
--
复制
发表时间：
1990
期刊：
影响因子：
--
通讯作者：
J. Czachurski
中科院分区：
文献类型：
--
作者：
H. Seller;S. König;J. Czachurski
通过左椎动脉人工灌注前腹外侧髓质（RVLM），对氯氯糖麻醉猫的交感兴奋神经元可能具有化学敏感性的假设进行了验证。通过双侧解剖颈动脉窦和迷走神经切断压力感受器和周围化学感受器的神经。记录白支T3 （WR-T3）或肾神经以监测交感神经活动。灌注生理盐水或含CO2气泡的林格氏溶液（10%-100%）可使交感神经活动和血压迅速显著升高。将溶液调整到相同的pH值（100% CO2的pH值为5.2）时，HCl的激发作用要弱得多。PCO2与交感神经活动呈线性关系。在延长的灌注期间（90 s），交感神经活动在初始兴奋后恢复到对照水平，在灌注停止后下降到对照水平以下。通过向RVLM中微量注射CoCl2阻断突触输入，不影响交感神经活动对二氧化碳泡溶液的反应，而自发交感神经活动和肋间神经T4到WR-T3的脊上体感交感反射明显减少。因此，我们认为RVLM中的交感兴奋性球脊髓神经元对动脉PCO2和pH的变化具有直接的化学敏感性。
The hypothesis that sympathoexcitatory neurones within the rostroventrolateral medulla (RVLM) may be chemosensitive was tested in chloralose-anaesthetized cats by artificial perfusion of the RVLM via the left vertebral artery. The baroreceptors and peripheral chemoreceptors were denervated by bilaterally dissecting the carotid sinus and vagus nerves. Either white ramus T3 (WR-T3) or the renal nerve was recorded to monitor sympathetic activity. Perfusion with saline or Ringer solution bubbled with CO2 (10%–100%) produced a rapid and pronounced increase in sympathetic activity and blood pressure. Solutions adjusted to the same pH (pH 5.2 for 100% CO2) with HCl resulted in a much weaker excitation. A linear relationship between PCO2 and sympathetic activity was demonstrated. During prolonged perfusion (90 s) sympathetic activity returned to the control level after initial excitation and fell below control levels when perfusion ceased. The sympathetic activity response to CO2-bubbled solutions was unaffected by blockade of synaptic input by microinjection of CoCl2 into the RVLM, whereas spontaneous sympathetic activity and the supraspinal somato-sympathetic reflex from intercostal nerve T4 to WR-T3 were markedly reduced. It is therefore concluded that sympathoexcitatory bulbospinal neurones in the RVLM are directly chemosensitive to changes in arterial PCO2 and pH.
猫化学感受器刺激和腹侧髓质冷却过程中的神经呼吸和循环相互作用。
DOI：
10.1113/jphysiol.1986.sp015931
发表时间：
1986
期刊：
The Journal of physiology
影响因子：
--
作者：
Millhorn,DE
通讯作者：
Millhorn,DE