CENTRAL RESPIRATORY AND CIRCULATORY EFFECTS OF Gymnodinium breve TOXIN IN ANAESTHETIZED CATS
CENTRAL RESPIRATORY AND CIRCULATORY EFFECTS OF Gymnodinium breve TOXIN IN ANAESTHETIZED CATS
复制标题
短裸甲藻毒素对麻醉猫中枢呼吸和循环系统的影响
DOI：
10.1111/j.1476-5381.1980.tb07930.x
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发表时间：
1980
影响因子：
7.3
通讯作者：
L. McCarthy
中科院分区：
文献类型：
--
作者：
H. Borison;S. Ellis;L. McCarthy
1 在用戊巴比妥麻醉的猫中，观察了呼吸、自发和诱发膈肌肌电图、血压、心率、间接诱导的胫骨前肌和瞬膜收缩以及延髓吸气中枢的电兴奋性。 2 短裸甲藻毒素 (GBTX) 通过静脉注射、脑动脉注射和脑室内注射。记录生理效应，同时将肺泡 Pco2 控制在恒定水平，除非改变气体张力以测量 CO2 通气反应性。 3 通过推注静脉注射足量的 GBTX 会引发由迷走神经介导的呼吸暂停、低血压和心动过缓的非快速过敏性反射反应三联征，与动脉压力感受器和化学感受器的神经支配无关。 4 迷走神经切断术后，额外注射 GBTX（静脉注射）会导致呼吸暂停、高血压和心动过速。用六甲铵阻断神经节可消除心血管效应。 5 动脉内和脑室内注射比静脉内注射所需的 GBTX 剂量较小，可导致呼吸不规则和心血管过度活跃。 6 尽管 GBTX 引起呼吸节律和心血管功能明显紊乱，但诱发的运动反应、延髓电兴奋性和 CO2 通气反应性在很大程度上没有受到影响。 7 结论是，GBTX 反射性地作用于迷走神经支配的受体，引起 Bezold-Jarisch 效应，但该毒素进一步作用于中枢，导致不规则屏气和高血压伴心动过速，最终导致呼吸和循环衰竭。
1 In cats anaesthetized with pentobarbitone, observations were made on respiration, spontaneous and evoked diaphragmatic electromyograms, blood pressure, heart rate, indirectly‐induced contractions of the anterior tibialis muscle and nictitating membrane, and electrical excitability of the inspiratory centre in the medulla oblongata. 2 Gymnodinium breve toxin (GBTX) was administered intravenously, intra‐arterially to the brain, and intracerebroventricularly. Physiological effects were recorded while alveolar Pco2 was controlled at a constant level except when changes in gas tension were made in order to measure C02‐ventilatory responsiveness. 3 Adequate doses of GBTX given intravenously by bolus injection elicited a non‐tachyphylactic reflex response triad of apnoea, hypotension and bradycardia mediated by the vagus nerves independently of arterial baroreceptor and chemoreceptor innervation. 4 After vagotomy, additional amounts of GBTX (i.v.) resulted in apneustic breathing, hypertension and tachycardia. The cardiovascular effects were abolished by ganglionic blockade with hexamethonium. 5 Smaller doses of GBTX were required intra‐arterially and intracerebroventricularly than by the intravenous route of injection to produce respiratory irregularity and cardiovascular hyperactivity. 6 Evoked motor responses, electrical excitability of the medulla oblongata and CO2‐ventilatory responsiveness were largely spared even though GBTX caused marked disturbances in respiratory rhythmicity and cardiovascular functions. 7 It is concluded that GBTX acts reflexly on vagally innervated receptors to evoke a Bezold‐Jarisch effect but that the toxin further acts centrally to cause irregular breathholding and hypertension with tachycardia, leading ultimately to respiratory and circulatory failure.