Hemodynamic effects of acute stressors in the conscious rabbit.
Hemodynamic effects of acute stressors in the conscious rabbit.
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急性应激源对清醒兔子的血流动力学影响。
DOI：
10.1152/ajpregu.1998.274.3.r814
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Hasser,EM
中科院分区：
文献类型：
--
作者：
Schadt,JC;Hasser,EM
长期使用仪器、有意识的兔子被用来测试这样的假设：空气喷射或振荡的感觉刺激会产生不同的血流动力学变化，这些变化可能分别适合主动或被动行为反应。两种压力源都会增加动脉压、中心静脉压和后躯血流量，并产生内脏血管收缩。这两种刺激都没有改变后躯电导。尽管空气喷射会增加心率和心输出量，但振荡却不会。这两种压力源对心率的动脉压力反射控制的影响不同。振荡将动脉压重置至较高水平，而心率最大值或最小值没有变化，而空气喷射则将心率和动脉压重置至较高水平。两种压力源都不影响压力反射敏感性。我们得出的结论是，有意识的兔子在暴露于急性应激源时至少表现出两种不同的心血管反应。喷气会产生包括心动过速在内的心血管反应，这类似于防御反应，似乎适合主动防御或飞行。另一方面，对振荡的响应似乎更适合被动响应，例如“冻结”行为。在暴露于任一压力源期间，压力反射会发生改变，从而允许心率和动脉血压同时增加，但敏感性保持不变，从而允许正常的时刻控制心率。
Chronically instrumented, conscious rabbits were used to test the hypothesis that sensory stimulation with an air jet or oscillation produces differential hemodynamic changes that may be appropriate for an active or a passive behavioral response, respectively. Both stressors increased arterial pressure, central venous pressure, and hindquarters blood flow and produced visceral vasoconstriction. Neither stimulus altered hindquarters conductance. Although air jet increased heart rate and cardiac output, oscillation did not. The two stressors affected arterial baroreflex control of heart rate differently. Oscillation reset arterial pressure to a higher level with no change in heart rate maximum or minimum, whereas air jet reset both heart rate and arterial pressure to higher levels. Neither stressor affected baroreflex sensitivity. We conclude that the conscious rabbit shows at least two distinct cardiovascular responses when exposed to acute stressors. Air jet produces a cardiovascular response including tachycardia, which resembles the defense reaction and appears appropriate for active defense or flight. The response to oscillation, on the other hand, appears better suited for a passive response such as “freezing” behavior. During exposure to either stressor, the baroreflex is altered to allow simultaneous increases in heart rate and arterial blood pressure, but the sensitivity is maintained, allowing normal moment to moment control of heart rate.