兴奋性氨基酸受体所介导细胞钙电流特征及其中L-SOP的作用途径  

Characteristics of membrane current induced by excitory amino acid receptors and the acting way of L-SOP

作　　者：张浚 王晖 金星 

机构地区：[1]广州军区药检所,广东广州510500

出　　处：《药学实践杂志》2008年第4期258-260,296,共4页Journal of Pharmaceutical Practice

基　　金：国家自然科学基金资助课题(39570827)

摘　　要：目的:研究兴奋性氨基酸受体各亚型所介导非洲爪蟾卵母细胞跨膜电流的特征及其中Ⅲ型受体激动剂L-SOP的作用途径。方法:用异硫氰酸胍-酚-氯仿法从成年大鼠脑中提取总RNA,以寡聚脱氧胸苷酸纤维素亲和层析法分离出mRNA并注射入非洲爪蟾卵母细胞使表达,以全细胞双电极电压钳位法灌流此卵母细胞。结果:100μM KA(kainate)(离子型)产生一主峰电流后缓慢下行,成为一稳定电流平台,最终脱敏,脱敏时间平均为37.57 min。2 txM QA(quisqualate)(代谢Ⅰ型)产生一峰值电流后转为一持续性钙振荡或直接出现钙振荡,振荡维持时间为(6.72±1.33)min,脱敏时间均随激动剂浓度的增加而缩短。0.8 mM L- SOP(L-phosphoserine)(代谢Ⅲ型)灌流产生规律性电流振荡,振荡时间为(20.17±8.47)min。此振荡电流可被代谢Ⅰ型受体拮抗剂L-AP_3所拮抗。结论:离子型、代谢Ⅰ型及代谢Ⅲ型受体均产生各自特征电流模型;L-SOP不仅是Ⅲ型受体的激动剂,而且是Ⅰ型受体的弱的激动剂,即细胞振荡电流是L-SOP通过Ⅰ型受体的作用途径而产生。Objective：To study the characters of membrane current of types of excitory amino acide and the acting way of Type Ⅲ mGluR（metabotropic glutamate receptor） agonist L-SOP among them. Methods： A total receptor RNA was isolated from adult rat brain by acid guanidnium thiocyanate-phenol-chloroform（AGPC） method, mRNA was isolated from the total RNA by oligo（dT）-cellucose chromatography, and was then micro-injected into Xenopus oocytes to express, through a two-microelectrode voltage clamp technique. The oocytes were refused with varieties of types of excitory amino acid. Results： 100 uM KA （kainate） （ ionic glutamate receptor） induced first a peak current and then a slowly descending current, which desentized at last. The mean maintained time was 37.57 rain. 2uM QA （quisqualate） （TYPE I mGluR ） induced regulary calcium oscillation with a maintained time of （6. 72 ± 1.33 ） min. Both of the maintained time were shortened the agonist concentration increased. 0, 8 mM L-SOP of TYPE ⅢmGluR agonist induced a kind of disciplinary oscillation with a maintained time of （20. 17 ± 8.47） min which was also shortened with an increasing concentration, while the oscillation coule be antagonized by TYPE Ⅰ mGluR antagonist L-AP3, Conclusion ： Each of these three types of glutamate amino acid receptors has its speuniquecial current mode when irritated ; L-SOP is not only an agonist of TYPE Ⅲ mGluR, but also a weak agonist of TYPE Ⅰ , that is, its acting way of producing oscillation is through TYPE Ⅰ receptor,

关 键 词：非洲爪蟾卵母细胞 信使RNA 兴奋性氨基酸受体 离子型谷氨酸受体 代谢型谷氨酸受体 KA QA L—SOP Carb 

分 类 号：Q25[生物学—细胞生物学]