大鼠孤束核内代谢型谷氨酸受体亚型7和8对心脏伤害性感受的调控作用

Regulation of metabotropic glutamate subtype 7 and 8 receptors in nucleus tractus solitarius in cardiac nociception in rats

目的:探讨孤束核(NTS)内第3组代谢型谷氨酸受体(mGluRs)及其亚型7和8对心脏-躯体运动反射(CMR)的影响,阐明NTS内第3组mGluRs及其亚型在心脏伤害性信息调控中的作用。方法:40只SD大鼠随机分为4组,L-(+)-2-amino-4-phosphonobutyric acid(L-AP4)组,NTS内分别微量注射第3组mGluRs激动剂L-AP4 0.1、1.0、10.0和20.0nmol;N,N’-diphenylmethyl-1,2-ethanediamine(AMN082)组,分别注射mGluRs7激动剂AMN082 1、2和4nmol;(S)-3,4-dicarboxyphenylglycine(DCPG)组,分别注射mGluRs8激动剂DCPG 4、6和8nmol;(RS)-α-methylserine-O-phosphate(MSOP)组,分别注射第3组mGluRs拮抗剂MSOP 20和100nmol,并于不同时间分别注射MSOP(20nmol)+L-AP4(10nmol)、MSOP(20nmol)+AMN082(2nmol)和MSOP(20nmol)+DCPG(6nmol)。观察各组大鼠CMR的改变。结果:与对照比较,L-AP4组和AMN082组CMR减少(P<0.05);DCPG组CMR增加(P<0.05);MSOP组注射20nmol MSOP后CMR无改变(P>0.05),注射100nmol MSOP后CMR增加(P<0.05);注射20nmol MSOP后再注射L-AP4或AMN082,CMR无改变(P>0.05)。结论:大鼠NTS内第3组mGluRs对心脏伤害性信息有紧张性抑制作用,mGluR7有抑制作用,而mGluR8有易化作用。

Objective To explore the role of metabotropic glutamate receptors （mGluRs）group Ⅲ and its subtypes mGluR7 and mGluR8 in nucleus tractus solitarius（NTS）in cardiac-somatic motor reflex （CMR）,and to clarify the modulation role of mGluR Ⅲ and its subtypes in NTS in cardiac nociceptoion.Methods 40 SD rats were randomly divided into L-AP4 group,microinjection of mGluRs Ⅲ agonist L-AP4 0.1,1.0,10.0 or 20.0 nmol in NTS;AMN082 group,microinjection of mGluR7 agonist AMN082 1,2 or 4 nmol;DCPG group,microinjection of mGluR8 agonist DCPG 4, 6 or 8 nmol;MSOP group, microinjection of mGluR Ⅲ antagonist MSOP 20 or 100 nmol,20 nmol MSOP＋410 nmol L-AP,20 nmol MSOP＋2 nmol AMN082,20 nmol MSOP＋6 nmol DCPG. The changes of CMR of the rats in various groups were observed.Results Compared with control,the CMR in L-AP4 and AMN082 groups was decreased （P〈0.05）;the CMR in DCPG group was increased （P〈0.05）;the CMR in MSOP group after injection of 20 nmol MSOP had no change （P〉0.05）;the CMR in MSOP group after injection of 100 nmol MSOP was increased （P〈0.05）;the CMR in MSOP group after injection of 20 nmol MSOP followed L-AP4 or AMNO82 had no change （P〉0.05）.Conclusion The group Ⅲ mGluRs in the NTS play an inhibitory role in cardiac nociception, and mGluR7 has anti-nociceptive effects while mGluR8 has pro-nociceptive effects.