Stuhr L E, Bergø G W, Tyssebotn I
Department of Physiology, University of Bergen, Norway.
Aviat Space Environ Med. 1994 Jun;65(6):531-8.
The effect of 1-5 bar O2 on left ventricular pressure (LVP), maximal velocity of LVP rise (+dP/dt) and fall (-dP/dt), systolic arterial pressure (APsys), pulse pressure (delta AP), heart rate (HR), and respiratory frequency (RF) was studied in anesthetized and conscious rats. At 1 bar O2, all blood pressure parameters increased significantly (9-56%) in both groups of rats, while RF fell (11-12%). HR fell only in conscious rats, while arrhythmias occurred in both groups. Compression to 5 bar O2 induced a significant further increase in all blood pressure parameters. HR fell further in the conscious rats. Arrhythmias were observed in increasing number during compression and at 5 bar O2. Elevation in estimated oxygen-consumption of the heart was found both during compression and at 5 bar O2. We conclude that O2 exposure markedly stimulates the myocardium by elevating the LVP, +dP/dt, and -dP/dt, thus elevating APsys and delta AP. Arrhythmias developed in both groups, while bradycardia occurred only in conscious rats.
在麻醉和清醒大鼠中研究了1-5巴氧气对左心室压力（LVP）、左心室压力上升最大速度（+dP/dt）和下降速度（-dP/dt）、收缩期动脉压（APsys）、脉压（ΔAP）、心率（HR）和呼吸频率（RF）的影响。在1巴氧气条件下，两组大鼠的所有血压参数均显著升高（9-56%），而RF下降（11-12%）。仅清醒大鼠的HR下降，而两组均出现心律失常。压缩至5巴氧气导致所有血压参数进一步显著升高。清醒大鼠的HR进一步下降。在压缩过程中和5巴氧气条件下，观察到心律失常的数量增加。在压缩过程中和5巴氧气条件下均发现心脏估计耗氧量升高。我们得出结论，氧气暴露通过升高LVP、+dP/dt和-dP/dt显著刺激心肌，从而升高APsys和ΔAP。两组均出现心律失常，而心动过缓仅发生在清醒大鼠中。
