大鼠心脏停搏期间心脏和肾脏α_1-肾上腺素能受体的变化

Changes in α 1adrenoceptor in heart and kidney during cardiac arrest in rats

目的：揭示心脏停搏期间机体肾上腺素能受体的变化规律，为指导心肺复苏期间更加合理地使用肾上腺素能类药物提供理论依据。方法：采用窒息使大鼠全身循环骤停作为动物模型，用放射性配基结合分析方法，研究动物在心搏停止期间心脏和肾脏α１肾上腺素能受体（α１受体）的变化。动物随机分为５组：正常对照（Ａ）组、手术对照（Ｂ）组、窒息１０分钟（Ｃ）组、窒息２０分钟（Ｄ）组和窒息３０分钟（Ｅ）组。结果：心脏α１受体在Ｂ和Ｃ组分别为（２２．０９±２．８２）ｆｍｏｌ／ｍｇｐｒ和（２１．８４±２．９４）ｆｍｏｌ／ｍｇｐｒ，与Ａ组的（３３．８８±２．７８）ｆｍｏｌ／ｍｇｐｒ比较均明显下降（Ｐ均＜０．０５）。肾脏α１受体在Ｃ组为（１８．９１±２．３６）ｆｍｏｌ／ｍｇｐｒ，与Ｂ组和Ａ组的（２８．６０±３．８２）ｆｍｏｌ／ｍｇｐｒ及（２７．９３±３．４０）ｆｍｏｌ／ｍｇｐｒ比较明显下降（Ｐ均＜０．０５）。随心脏停搏时间延长，心脏和肾脏α１受体在Ｄ和Ｅ组均有增加趋势。其中，Ｅ组肾脏α１受体为（３５．２３±４．５５）ｆｍｏｌ／ｍｇｐｒ，与Ｃ组比较明显增加（Ｐ＜０．０５）。各组心脏和肾脏受体的亲和力变化不显著。结论：在心脏骤停早期，心脏和肾脏α１受体?

Objective:To investigate the regularity of changes in α 1adrenoceptor (α 1AR) and provide theoretical basis for using adrenergics rationally during cardiopulmonary resuscitation (CPR).Methods:Changes in α 1AR during cardiac arrest were determined using ra dioligand binding technique (prazosin,α 1selective antagonist) in heart and kidney of an asphyxiated rat model.Fortynine Wister rats were randomly divided into five groups,including normal control (A),operation (B),asphyxiated tenminute (C),twentyminute (D) and thirtyminute (E) groups.Results:It showed that the α 1AR number of heart and kidney in group A,B,C,D and E were(33 88±2 78) and (27 93±3 40),(22 09±2 82) and (28 60±3 82),(21 84±2 94) and (18 91±2 36),(24 21±3 09) and (22 71±2 82),(30 81±3 64) and (35 23±4 55) pmol/g protein,respectively.α 1AR number of heart in group B and group C were significantly lower than that in group A(both P <0 05).Also,α 1AR number of kidney in group C was much lower than that in group A,B and E,respectively (all P <0 05).As cardiac arrest time was prolonged,α 1AR number of heart and kidney tended to increase in both group D and group E.However,the α 1AR affinities were not significantly different among the five groups.Conclusions:In the early stage after cardiac arrest,the α 1AR number in rat's heart and kidney was significantly decreased (downregulation),but it might increase as cardiac arrest time is prolonged (upregulation).Therefore,adrenergics should be rationally used according to changes in α 1AR at different stages during CPR.