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大鼠三叉神经节神经元膜P2X嘌呤受体的特征

谷远征, 殷光甫, 关兵才, 李之望

华中科技大学同济医学院神经生物学系.湖北,武汉 430030

摘要

采用全细胞膜片钳技术研究了大鼠三叉神经节（trigeminal ganglion，TG）神经元膜P2X嘌呤受体的特征。结果发现：大部分受检细胞（78.9％，142／180）对ATP敏感，ATP--激活电流有明显的浓度依赖性。少数细胞无反应（21.1％，38／180）。在对ATP敏感的142个细胞中，绝大部分引起一内向电流（95.1％，135／142），少数为外向电流（2.1％，3／142），另有部分细胞出现双相电流（2.8％，4／142）。引起的内向电流在小直径细胞（<30#mu#m）上多表现为快去敏感电流，对vanilloid高度敏感；在中等大小的细胞（30---40#mu#m）上多表现为慢去敏感电流，对vanilloid不敏感：绝大多数大细胞（>40#mu#m）对ATP和vanilloid均不敏感。此外，电流的波形与细胞直径密切相关。无论小细胞还是中等细胞其I--V曲线均表现出明显的内向整流趋势。作者还研究了ATP--激活电流的动力学特征，并观察了P2嘌呤受体激动剂、拮抗剂的效应。结果提示：不同类型的ATP受体--离子通道在不同类型的TG神经元上的表达具有不同的特点。

关键词： 腺苷三磷酸; 嘌呤受体; 三又神经节; 膜片钳技术

Characteristics of P2X purinoceptors in the membrane of rat trigeminal ganglion neurons

Gu Yuanzheng, Yin Guangfu, Guan Bingcai, Li Zhiwang

Department of Neurobiology, Tongji Medical College of Huazhong University of Science and Technology.Wuhan 430030,Hubei

Abstract

The characteristics of purinoceptors in the membrane of rat trigeminal ganglion （TG） neurons were studied by using wholecell patch clamp technique. The results showed that most of neurons examined （78.9%, 1421180） were responsive to ATP in a concentration-dependent manner; the others （21.1%, 38/180） were ATP insensitive. Of the ATP-sensitive cells, the majority （95.1%, 135/142） responded to ATP with an inward current, a few （2.1%, 31142） with an outward current, and the rest （2.8%, 4/142） with biphasic current. Small sized cells （<30 #mu#m） responded to ATP with a rapid desensitizing inward current and were highly sensitive to vanilloid; the medium sized ceils （30--40#mu#m） responded to ATP with slow desensitizing inward current and were not sensitive to vanilloid; while the majority of large sized cells （>40#mu#m） did not respond to ATP and vanilloid. The waveform of ATP-activated inward currents was related to the cell diameter. The I-V curves for both small and medium sized cells manifested obvious inward rectification. Furthermore, we studied the kinetic features of ATP-activated currents and the effects of P2 purinoceptor agonists and antagonists on I ATP. The findings suggest that ATP receptor-ion channels are expressed differently among different types of rat TG neurons.

Key words: adenosine triphosphate;purinoceptor;trigeminal ganglion;patch clamp technique

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引用本文：

谷远征, 殷光甫, 关兵才, 李之望. 大鼠三叉神经节神经元膜P2X嘌呤受体的特征[J]. 生理学报 2006; 58 (2): .

Gu Yuanzheng, Yin Guangfu, Guan Bingcai, Li Zhiwang. Characteristics of P2X purinoceptors in the membrane of rat trigeminal ganglion neurons. Acta Physiol Sin 2006; 58 (2): (in Chinese with English abstract).