关键词: 组胺H3 受体;AtT-20细胞;促肾上腺皮质激素;G蛋白

    摘 要:目的 观察组胺受体激动剂对AtT-20细胞分泌ACTH的影响，并探讨G蛋白在组胺H3 受体信号转导机制中的作用. 方法 选用文献报道的高表达组胺H3 受体的垂体细胞瘤AtT-20作为观察系统，用放免分析法测定给予组胺受体激动剂后各时间点细胞上清液中ACTH分泌量的变化，并观察药物对细胞增殖的影响. 结果 组胺H3 受体激动剂R-(α)-MeHA(0.1μmol L

    -1 )作用8h能明显促进ACTH的释放，释放量为1920μg L-1 ，与同时间对照组(780μg L

    -1 )相比，明显增高(P<0.01);H1 和H2 激动剂则无此作用.且R-(α)-MeHA引起CTH分泌的效应能被H3 受体特异性拮抗剂thioperamide所拮抗，而H1 受体和H2 受体拮抗剂均不影响R-(α)-MeHA的效应.R-(α)-MeHA作用8和24h，对细胞增殖无明显影响.用G蛋白失活剂NEM预先处理细胞后，取消了R-(α)-MeHA增强AtT-20细胞ACTH分泌的效应. 结论 特异性激动组胺H3 受体后能引起兴奋-分泌耦联过程，其信号转导过程中有G蛋白的参与.

    Histamine H3 receptors regulate ACTH release by AtT┐20cells

    XIE Jian-Jun，LUO Xiao-Xing，ZHAO De-Hua

    Department of Parmacology，Faculty of Preclinical Medicine，Fourth Military Medical University，Xi'an710033，China

    Keywords:histamine H3 receptors;AtT-20cells;adrenocor-ticotropin;G protein

    Abstract:AIM To investigate the signal transduction mech-anism of histamine H 3 receptor.METHODS The adrenocor-ticotropic hormone(ACTH)levels of supernatants on AtT-20cells from the pituitary gland tumor were measured by ra-dioimmunoassay at the given time after histamine agonists were administrated and the effects of R-(α)-methylhistamine on the cells proliferation were observed.RESULTS The H3 receptor specific agonist ......