Effects of graded muscle contractions on spinal cord substance P release, arterial blood pressure, and heart rate.
Effects of graded muscle contractions on spinal cord substance P release, arterial blood pressure, and heart rate.
复制标题
分级肌肉收缩对脊髓 P 物质释放、动脉血压和心率的影响。
DOI：
10.1161/01.res.73.6.1024
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发表时间：
1993
影响因子：
20.1
通讯作者：
Mitchell,JH
中科院分区：
文献类型：
--
作者：
Wilson,LB;Fuchs,IE;Mitchell,JH
用α-氯醛糖麻醉猫，观察了脊髓后角P物质（SP）样免疫反应性（SP-LI）的释放和高、低张力收缩时心血管的变化。在10分钟内，诱导了7次收缩（HT或LT）。每次收缩持续20秒，然后是80秒的静止期。HT收缩的张力时间指数（TTI）为2751 +/- 348 kg.s（平均值+/- SD），大于LT收缩的TTI 813 +/- 167 kg.s。HT收缩比LT收缩引起更多的SP-LI释放：对于两种类型的收缩，SP-LI分别从0.18 +/- 0.02增加到0.32 +/- 0.03 fmol/100 microL和从0.18 +/- 0.02增加到0.25 +/- 0.04 fmol/100 microL。伴随着这种更大的SP-LI释放，HT收缩引起的平均动脉压（34 +/- 16对11 +/- 4 mm Hg）和心率（18 +/- 7对8 +/- 4次/分钟）的增加比LT收缩更大。SP-LI、平均动脉压和心率的这些变化在切断L-5-S-2背根和腹根后重复收缩时，或在用三碘化镓胺肌麻痹后重复电刺激腹根时几乎被消除。这些结果表明，收缩诱发的SP-LI释放在背角是与发达的张力。此外，这些数据提供了额外的支持的假设，SP从肌肉传入神经中枢末梢的释放起着介导的心血管反应的骨骼肌静态收缩的作用。
The release of substance P (SP)-like immunoreactivity (SP-LI) in the dorsal horn of the spinal cord and the cardiovascular changes to both high-tension (HT) and low-tension (LT) contractions were determined using alpha-chloralose-anesthetized cats. Over a 10-minute period, seven contractions (HT or LT) were induced. Each contraction was 20 seconds in duration and was followed by an 80-second quiescent period. The tension-time index (TTI) for the HT contractions was 2751 +/- 348 kg.s (mean +/- SD), which was greater than the TTI of 813 +/- 167 kg.s for the LT contractions. The HT contractions caused a greater release of SP-LI than the LT contractions: SP-LI increased from 0.18 +/- 0.02 to 0.32 +/- 0.03 fmol/100 microL and from 0.18 +/- 0.02 to 0.25 +/- 0.04 fmol/100 microL for the two types of contractions, respectively. Concomitant with this greater SP-LI release, HT contractions caused larger increases in mean arterial pressure (34 +/- 16 versus 11 +/- 4 mm Hg) and heart rate (18 +/- 7 versus 8 +/- 4 beats per minute) than did the LT contractions. These changes in SP-LI, mean arterial pressure, and heart rate were virtually abolished when the contractions were repeated after sectioning the L-5-S-2 dorsal and ventral roots or when the electrical stimulation of the ventral roots was repeated after muscle paralysis with gallamine triethiodide. These results demonstrate that contraction-evoked SP-LI release in the dorsal horn is related to the developed tension. Furthermore, these data provide additional support for the hypothesis that the release of SP from the central terminations of muscle afferents plays a role in mediating the cardiovascular responses to static contraction of skeletal muscle.