摘要
将羊外周血淋巴细胞ｍＲＮＡ注入非洲爪蟾卵母细胞胞浆内，借助卵母细胞的翻译系统，表达羊外周血淋巴细胞的Ｍ型乙酰胆碱（Ａｃｈ）受体并移植到卵母细胞膜上，用电压钳位仪检测表达受体电流。结果发现Ａｃｈ可诱发卵母细胞产生电流反应，该反应能被Ｍ型Ａｃｈ受体阻断剂硫酸阿托品阻断，但不能被Ｎ型受体阻断剂氯化筒箭毒阻断，提示：淋巴细胞存在Ｍ型Ａｃｈ受体，其基本特性为：１）Ａｃｈ浓度为１０－８～１０－３ｍｏｌ／Ｌ时，与电流幅度呈线性关系，１０－６ｍｏｌ／ＬＡｃｈ为１／２最大有效浓度，产生的电流幅度为３８００±１１１６ｎＡ；２）当钳制电位在－８０～±２０ｍＶ范围内，ＶＩ关系曲线为直线，逆转电位约为－２０±１２５ｍＶ，该值接近卵母细胞的Ｃｌ－平衡电位；３）用ＳＯ２－４取代灌注液中５０％的Ｃｌ－，电流幅度下降４４８９％，逆转电位正向偏移１６±１ｍＶ。以上结果进一步证明Ｃｌ－是表达Ｍ型Ａｃｈ电流的主要载流离子。淋巴细胞表达Ｍ型受体的Ａｃｈ电流证明羊淋巴细胞上有完整的Ｍ型Ａｃｈ受体。
The aim of this work was to define the features of ion current of acetylcholine(Ach) receptors of sheep lymphocyte. The receptors were expressed by the translation system of Xenopus oocytes after injection of sheep lymphocyte mRNA. The ion current of expressed receptor was tested by voltage clamping method. Before injection of mRNA, quinuclidinyl benzilate was applied to block the native muscarinic receptors of the oocytes to eliminate their interference with expressed muscarinic receptors. Ion current induced by Ach was observed in Xenopus oocytes containing the expressed receptors. Atropine sulfate(10 -6 mol/L) was able to block it, whereas d Tubocurare chloride(10 -3 mol/L) was not. It is suggested that this Ach response is muscarinic in nature.The following features of the current were observed: 1. From 10 -8 mol/L to 10 -3 mol/L of Ach, the concentration amplitude relation curve was linear in nature; The half maximum effect of Ach concentration was about 10 -6 mol/L. The amplitude was 38 00±11 16 nA(n=6); 2. When the holding potential ranged from -80 mV to +20 mV, the V I relation curve was linear; 3. The reversal potential was -20±1 25 mV (n=9)which coincided with Cl - equilibrium potential in Xenopus oocytes. Replacing 50% Cl - of perfusion solution with SO 2- 4, the current amplitude of Ach was reduced 44 89%, and the reversal potential shifted to positively 16±1 mV(n=8), indicating that chloride ion is the main species responsible for carrying Ach current. Based on these observations, it is reasonable to conclude that integrate or complete muscarinic Ach receptors are distributed over sheep lymphocytes.
出处
《动物学报》
SCIE
CAS
CSCD
1998年第2期213-218,共6页
ACTA ZOOLOGICA SINICA
关键词
淋巴细胞
爪蟾
卵母细胞
MRNA
M型
电流
Lymphocyte, Xenopus oocyte, mRNA, Voltage clamping Muscarinic Ach current
