Comparative vascular effects of stimulation continuously and in bursts of the sympathetic nerves to cat skeletal muscle.
Comparative vascular effects of stimulation continuously and in bursts of the sympathetic nerves to cat skeletal muscle.
复制标题
交感神经连续刺激和突发刺激对猫骨骼肌的血管效应比较。
DOI：
--
复制
发表时间：
1983
期刊：
影响因子：
--
通讯作者：
P. Andersson
中科院分区：
文献类型：
--
作者：
P. Andersson
最近的电生理学研究表明，体内交感血管收缩纤维放电通常发生在间歇性的高频脉冲中，通过提高脉冲内频率或更常见的是通过缩短脉冲间隔来增加活动。本研究描述了猫骨骼肌中电阻血管和电容血管对血管收缩纤维电刺激的反应，并模拟了体内放电模式的特征。脉冲刺激（持续1秒）可以在恒定的脉冲间隔（5或10秒）下以不同的脉冲内脉冲速率（从5到160赫兹）进行，也可以在恒定的脉冲内频率（16或32赫兹）下以不同的脉冲间隔（从32到2秒）进行。相比之下，连续刺激的频率为0.5 ~ 16hz。两种类型的脉冲刺激都能够引起电阻血管和电容血管的持续收缩，这与脉冲总数/单位时间有关。不同间隔的脉冲刺激与间隔4 s的32 Hz脉冲连续刺激同样有效。在不同脉冲速率下，脉冲对刺激的反应在40hz时达到峰值，较高的脉冲内频率效果较差，至少在阻力血管中是如此。数据表明，电阻血管和电容血管对交感放电率的反应逐渐增加，直到大约40赫兹，如果激发发生在脉冲中，并且可以通过缩短脉冲间隔来实现有效的控制。因此，骨骼肌的交感神经放电可能远远超过10hz，这是先前认为的生理放电范围的上限。
Recent electrophysiological studies indicate that sympathetic vasoconstrictor fibre dicharge in vivo usually occurs in intermittent high frequency bursts, increased activity being established by raised intra-burst frequency or, more commonly, by shortened burst intervals. The present study describes the responses of the resistance and capacitance vessels in cat skeletal muscle to electrical vasoconstrictor fibre stimulation with characteristics simulating the discharge pattern in vivo. Stimulation in bursts (1 s duration) was applied either at varying intra-burst impulse rates (from 5 to 160 Hz) at constant burst interval (5 or 10 s), or at varying burst intervals (from 32 to 2 s) at constant intra-burst frequency (16 or 32 Hz). For comparison, continuous stimulation was made at rates from 0.5 to 16 Hz. Both types of burst stimulation were capable of evoking maintained constrictions in the resistance and capacitance vessels, graded in relation to the total number of impulses/unit time. Stimulation in bursts at varying intervals was as effective as continuous stimulation with maximal constriction reached at 32 Hz bursts at 4 s intervals. The responses to stimulation in bursts at varying impulse rates peaked at 40 Hz, higher intraburst frequencies being less effective, at least in the resistance vessels. The data suggests that the resistance and capacitance vessels are gradedly responsive to sympathetic discharge rates up to about 40 Hz provided excitation occurs in bursts and, that an effective control can be achieved especially by shortening the burst interval. Sympathetic firing in skeletal muscle may thus well exceed 10 Hz, previously believed to be the upper physiological discharge range.