鸡视网膜MEL受体的表达及部分电生理、药理特性的研究  

EXPRESSION OF THE CHICKEN RETINA MELATONINHIGHSENSITIVE RECEPTOR AND SOME OF ITS ELECTROPHYSIOLOGICAL AND PHARMACOLOGICAL CHARACTERISTICS

作　　者：白小川[1] 苏嘉斌[1] 包永德[1] 

机构地区：[1]中国科学院上海生理研究所

出　　处：《中国神经科学杂志》1999年第1期7-12,共6页

摘　　要：褪黑激素（ＭＥＬ）是松果体和视网膜分泌的一种重要内分泌激素，它参与生物季节周期昼夜节律，视网膜信号调制及其他多种重要生理功能的调节。关于鸟类视网膜中ＭＥＬ受体的定位和亲和性类型的研究已有报道，然而由于所用方法的限制，对它的电生理特性知之甚少。我们首次成功地在爪蟾卵母细胞上表达了鸡视网膜ＭＥＬ受体，并利用双电极电压箝技术及常用的药物灌流的方法研究了它的部分电生理、药理学特性。我们发现，这种表达的ＭＥＬ受体是高度敏感的，１ｐｍｏｌ／Ｌ的ＭＥＬ即可诱导出一个振荡型的内向电流，该电流很难失敏，反转电位接近－２６ｍＶ，可被高浓度的氯通道阻断剂９－ＡＣ明显抑制，亦可被钙离子螯合剂如ＢＡＰＴＡ－ＡＭ阻断。这些证据提示，这种表达的ＭＥＬ受体是通过激活钙依赖的氯离子通道而起作用。由于该电流不受咖啡因的影响，与目前已表达出的哺乳动物及鸡脑的ＭＥＬ受体有明显的差异。此外，该电流还可受到锌离子的调制。这些工作为今后研究的深入创造了良好条件。Due to the limitation of the used research approaches,little knowledge was obtained about the electrophysiological characteristics of melatonin receptors, now we use the oocytes as express system,after microinjection of poly(A)+RNA of chick retina,Xenopus oocytes expressed functional melatoninhighsensitive receptors.Electrophysiological and pharmacological data were obtained by voltage clamp technique and pharmacological method.Melatonin evoked an inward oscillatory current even in a concentration of 1 pmol/L.The receptor seemed difficult to desensitize.The melatoninevoked current was blocked by 9AC with the reversal potential approximately 26 mV.It was inhibited by BAPTAAM but not by caffeine.So the receptor seemed to make effects through exciting the calcium dependent chloride channel.In addition,high concentration of zinc also inhibited that current.

关 键 词：褪黑激素 受体 鸡 视网膜 电生理 药理学 

分 类 号：Q576[生物学—生物化学] R977.1[医药卫生—药品]