NMDA receptor blockade in cat dorsal horn blunts reflex pressor response to muscle contraction and stretch.
NMDA receptor blockade in cat dorsal horn blunts reflex pressor response to muscle contraction and stretch.
复制标题
猫背角的 NMDA 受体阻断会减弱对肌肉收缩和伸展的反射性升压反应。
DOI：
10.1152/ajpheart.1996.270.2.h500
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Wilson,LB
中科院分区：
文献类型：
--
作者：
Hand,GA;Meintjes,AF;Keister,AW;Ally,A;Wilson,LB
用微透析法将NMDA受体拮抗剂DL-2-氨基-5-膦酰基戊酸（AP-5）注入麻醉猫背角L7或L 6和S1水平，研究了NMDA受体在静态肌肉收缩和被动牵张引起的反射性升压反应中的作用。电刺激切断的L7和S1腹根引起的收缩增加了平均动脉压（MAP）和心率（HR）。被动拉伸的张力类似于那些产生的收缩也增加了这些变量。这些心血管变化不受透析AP-5（10 mM）进入L7背角的影响。将AP-5的注射器浓度增加至100 mM，分别从62 +/- 8至31 +/- 6 mmHg和18 +/- 4至12 +/- 4次/分钟减弱升压和HR反应。AP-5减弱了肌肉拉伸引起的MAP增加（59 +/- 10对41 +/- 10 mmHg）。同时微透析AP-5（10或100 mM）进入L 6和S1脊髓水平的背角也钝化了MAP和HR对收缩和拉伸的反应。这些结果表明，NMDA受体在中枢神经系统脊髓水平介导MAP和HR对静态肌肉收缩的反应中起作用。此外，这些数据表明，从肌肉传入的侧枝部分介导的反射性心血管反应引起的肌肉收缩和伸展。
The role of N-methyl-D-aspartate (NMDA) receptors in the reflex pressor response to static muscle contraction and passive stretch was examined by microdialyzing the NMDA receptor antagonist DL-2-amino-5-phosphonovalerate (AP-5) into the L7 or L6 and S1 levels of the dorsal horn of anesthetized cats. Contraction, elicited by electrical stimulation of the cut L7 and S1 ventral roots, increased mean arterial pressure (MAP) and heart rate (HR). Passive stretch at tensions similar to those generated by contraction also increased these variables. These cardiovascular changes were unaffected by dialyzing AP-5 (10 mM) into the dorsal horn at L7. Increasing the syringe concentration of AP-5 to 100 mM attenuated the pressor and HR responses from 62 +/- 8 to 31 +/- 6 mmHg and 18 +/- 4 to 12 +/- 4 beats/min, respectively. AP-5 blunted the increase in MAP (59 +/- 10 vs. 41 +/- 10 mmHg) evoked by muscle stretch. Simultaneously microdialyzing AP-5 (10 or 100 mM) into the dorsal horn at the L6 and S1 spinal levels also blunted the MAP and HR responses to contraction and stretch. These results suggest that NMDA receptors play a role in mediating the MAP and HR responses to static muscle contraction at the spinal level of the central nervous system. Furthermore, these data demonstrate that collaterals from muscle afferents partially mediate the reflex cardiovascular responses evoked by muscle contraction and stretch.