Role of myogenic response in enhancing autoregulation of flow during sympathetic nerve stimulation.
Role of myogenic response in enhancing autoregulation of flow during sympathetic nerve stimulation.
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肌源性反应在增强交感神经刺激期间血流自动调节中的作用。
DOI：
10.1152/ajpheart.1992.263.4.h1177
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Johnson,PC
中科院分区：
文献类型：
--
作者：
Ping,P;Johnson,PC
在体外培养的猫缝匠肌上，用活体显微镜观察了持续交感神经刺激对血流自动调节的影响。在没有交感神经刺激（SNS）的情况下，二级小动脉在动脉压从110 mmHg降至60 mmHg的过程中显示出不显著的扩张（3%）;容积流量与压力降低一致。在SNS期间，这些小动脉显著收缩（25%），并且它们在减压期间的扩张（20%）是显著的，并且显著大于没有SNS的情况。在减压过程中，体积流量显著增加（20-60%），这种现象称为流量超调节。在持续SNS减压过程中，环境氧浓度从0升高至20%引起小动脉收缩，但并没有消除小动脉扩张。小动脉对静脉压升高的反应也受到持续SNS的显著影响。没有SNS，三级小动脉显示轻微扩张（4%）时，股静脉压升高10毫米汞柱。在SNS期间，这些小动脉显著收缩，并且当静脉压升高时进一步收缩（20%）。使用局部麻醉剂（利多卡因），我们确定局部静脉-动脉反射不参与小动脉收缩。我们的数据表明，在持续的交感神经刺激的流量超调节不是由于代谢因素，而是一个增强的肌源性反应。
The effect of sustained sympathetic nerve stimulation on autoregulation of blood flow was examined in the exteriorized cat sartorius muscle using intravital microscopy. Without sympathetic nerve stimulation (SNS), second-order arterioles showed insignificant dilation (3%) during arterial pressure reduction from 110 to 60 mmHg; volume flow fell coincident with pressure reduction. During SNS, these arterioles constricted significantly (25%), and their dilation during pressure reduction (20%) was significant and was significantly greater than that without SNS. Volume flow increased significantly (20-60%) during pressure reduction, a phenomenon termed superregulation of flow. Elevation of ambient oxygen in the suffusate from 0 to 20% caused arteriolar constriction but did not abolish arteriolar dilation during pressure reduction under sustained SNS. Arteriolar response to venous pressure elevation was also affected significantly by sustained SNS. Without SNS, third-order arterioles showed slight dilation (4%) when femoral venous pressure was elevated by 10 mmHg. During SNS, these arterioles constricted significantly and constricted further (20%) when venous pressure was elevated. Using a local anesthetic (lidocaine), we determined that a local venous-arteriolar reflex was not involved in the arteriolar constriction. Our data suggest that superregulation of flow during sustained sympathetic nerve stimulation is not due to metabolic factors but rather to an enhanced myogenic response.