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激活颈动脉体mGluR1抑制慢性间歇性低氧所致大鼠颈动脉体可塑性

李超红^1,2, 赵晨露¹, 刘玉珍^1,*

¹新乡医学院第一附属医院，河南省神经修复重点实验室，生命科学研究中心，卫辉 453100；²重庆医科大学附属第二医院心血管内科，重庆 404100

摘要

本文旨在探讨代谢型谷氨酸受体1 (metabotropic glutamate receptor 1, mGluR1)在慢性间歇性低氧(chronic intermittent hypoxia, CIH)所致大鼠颈动脉体可塑性中的作用。对Sprague Dawley (SD)大鼠CIH (6%~21% O2，4 min/循环，8 h/天)处理4周，无创法测量其尾动脉血压。通过RT-qPCR检测颈动脉体mGluR1的mRNA表达水平；Western blot检测颈动脉体mGluR1的蛋白表达水平；通过离体胞外记录技术描记颈动脉体窦神经放电，并给予急性间歇性低氧(5% O2 1 min间歇95% O2 5 min，10次)诱导颈动脉体窦神经感觉长时程易化(sensory long-term facilitation, sLTF)，观察mGluR1在CIH所致颈动脉体窦神经sLTF中的作用。结果显示：与对照组相比较，CIH处理4周的大鼠收缩压(P < 0.001)、舒张压(P < 0.005)、平均动脉压(P < 0.001)均明显升高。与对照组相比，CIH组大鼠颈动脉体中mGluR1的mRNA及蛋白表达水平均下降(P < 0.01)。与对照组大鼠相比，CIH组大鼠可诱导颈动脉体窦神经sLTF；预先应用I组代谢型谷氨酸受体激动剂(S)-3,5-二羟基苯基甘氨酸(DHPG)激活颈动脉体mGluR1则抑制CIH大鼠颈动脉体窦神经sLTF (P < 0.005)。上述结果提示，激活颈动脉体mGluR1可抑制CIH所致颈动脉体可塑性。

关键词： 代谢型谷氨酸受体1 ; 慢性间歇性低氧; 颈动脉体可塑性

Activation of metabotropic glutamate receptor 1 inhibits chronic intermittent hypoxia-induced carotid body plasticity in rats

LI Chao-Hong^1,2, ZHAO Chen-Lu¹, LIU Yu-Zhen^1,*

¹The First Affiliated Hospital of Xinxiang Medical University, Henan Key Laboratory of Neural Regeneration and Repairment, Life Sciences Research Center, Weihui 453100, China；²Department of Cardiology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 404100, China

Abstract

The purpose of the present study was to explore the role of carotid body metabotropic glutamate receptor 1 (mGluR1) in chronic intermittent hypoxia (CIH)-induced carotid body plasticity. Sprague Dawley (SD) rats were exposed to CIH (6%–21% O2, 4 min/cycle, 8 h/day) for 4 weeks. The blood pressure of rats was monitored non-invasively by tail-cuff method under consciousness. RT-qPCR was used to examine the mRNA expression level of mGluR1 in rat carotid body. Western blot was used to detect the protein expression level of mGluR1 in rat carotid body. The role of mGluR1 in CIH-induced carotid body sensory long-term facilitation (sLTF) was investigated by ex vivo carotid sinus nerve discharge recording, and the carotid body sLTF was evoked by a 10-episode of repetitive acute intermittent hypoxia (AIH: 1 min of 5% O2 interspersed with 5 min of 95% O2). The results showed that: 1) CIH increased the systolic blood pressure (P < 0.001), diastolic blood pressure (P < 0.005) and mean arterial blood pressure (P < 0.001) of rats; 2) CIH decreased the mRNA and protein levels of mGluR1 in the rat carotid body (P < 0.01); 3) 4 weeks of CIH induced carotid body sLTF significantly, exhibiting as an increasing baseline sensory activity during post-AIH, which was inhibited by application of an agonist of group I metabotropic glutamate receptors, (S)-3,5-dihydroxyphenylglycine (DHPG), during sLTF induction (P < 0.005). In summary, these results suggest that activation of mGluR1 inhibits CIH-induced carotid body plasticity in rats.

Key words: metabotropic glutamate receptor 1; chronic intermittent hypoxia;

收稿日期：　　录用日期：

通讯作者：刘玉珍　　E-mail: yuzhenliu@xxmu.edu.cn

DOI: 10.13294/j.aps.2023.0062

引用本文：

李超红, 赵晨露, 刘玉珍. 激活颈动脉体mGluR1抑制慢性间歇性低氧所致大鼠颈动脉体可塑性[J]. 生理学报 2023; 75 (5): 629-635.

LI Chao-Hong, ZHAO Chen-Lu, LIU Yu-Zhen. Activation of metabotropic glutamate receptor 1 inhibits chronic intermittent hypoxia-induced carotid body plasticity in rats. Acta Physiol Sin 2023; 75 (5): 629-635 (in Chinese with English abstract).