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为了研究鸟嘌呤核苷酸结合蛋白（Ｇ蛋白）在慢性输入去甲肾上腺素（ＮＥ）所致大鼠心脏和主动脉对ＮＥ脱敏反应中的作用，采用大鼠皮下植入微量泵持续输入ＮＥ（０．１ｍｇ·ｋｇ－１·ｈ－１）模型，Ｇ蛋白α亚基及其ｍＲＮＡ水平用相应的抗体和ｃＤＮＡ探针按Ｗｅｓｔｅｒｎｂｌｏｔ和Ｎｏｒｔｈｅｒｎｂｌｏｔ法测定．结果显示：输注６ｄＮＥ的大鼠主动脉中Ｇｓα，Ｇｉα和Ｇｏα均显著下降，但其ｍＲＮＡ无显著改变；心房及心室中Ｇｉα显著升高，Ｇｓα，Ｇｏα维持不变，而Ｇｉ２αｍＲＮＡ升高，心房中ＧｓαｍＲＮＡ下降．输入ＮＥ３ｄ的大鼠心房及心室Ｇｉα，Ｇｏα无改变，Ｇｓα４５和４２ｋＤ带显著下降，但５２ｋＤ带升高；心室中ＧｏαｍＲＮＡ的３．８和３．４ｋｂ带显著升高，而心房中５．４ｋｂ带升高，心室Ｇｉ３αｍＲＮＡ下降．上述结果表明输入ＮＥ可引起Ｇ蛋白的动态变化，提示Ｇ蛋白在ＮＥ慢性刺激引起的心血管反应性降低中可能起一定的作用，其早期以Ｇｓ下降为主，６ｄ时则以Ｇｉ升高为主
Order to investigate the role of guanine nucleotide binding protein (G-protein) in the desensitization of NE induced by NE in rat heart and aorta, the rats were subcutaneously implanted with a micro-pump NE (0.1 mg · kg-1 · h-1) model, G protein α subunit and its mRNA levels were determined by Western blot and Northern blot using the corresponding antibodies and cDNA probes. The results showed that the Gsα, Giα and Goα in the aorta of 6dNE rats were significantly decreased, but there was no significant change in the mRNA expression. Giα was significantly increased in atria and ventricle, Gα and Goα were unchanged, Gi2α mRNA was elevated, Gsα mRNA decreased. There was no change in the Giα and Goα in the atria and ventricle of NE3d rats, while the Gsα45 and 42kD bands were significantly decreased but the 52kD band was increased. The 3.8 and 3.4kb bands of Goα mRNA in the ventricles were significantly increased, while the 5.4kb band Increased, ventricular Gi3α mRNA decreased. The above results indicate that the input of NE can cause the dynamic change of G protein, which suggests that G protein may play a role in the reduction of cardiovascular reactivity induced by chronic neurotoxicity of NE. The early Gs decrease and G increased the Lord