Effects of long-term application of dopamine HCl on dopamine agonist-induced cAMP production in rat renal cortex  

TX Effects of long term application of dopamine HCl on dopamine agonist induced cAMP production in rat renal cortex

作　　者：赵荣瑞[1] 靳小红[1] 朱琳[1] 王文泽[1] 

机构地区：[1]山西医科大学生理教研室

出　　处：《中国药理学报》1998年第1期35-38,共4页Acta Pharmacologica Sinica

摘　　要：目的：观察长期给予盐酸多巴胺对大鼠肾皮质多巴胺受体亚型所介导的腺苷酸环化酶活性的影响．方法：用放免分析法测定ｃＡＭＰ含量，作为反映多巴胺受体功能的指标．结果：长期给予盐酸多巴胺可显著减少肾皮质由非诺多泮引起的ｃＡＭＰ增加的量和在Ｓｃｈ２３３９０存在下由ＰＢＤＡ引起的ｃＡＭＰ降低的量，但其变量百分比则与对照组无显著差异．Ｓｃｈ２３３９０可阻断由非诺多泮和ＰＢＤＡ引起的ｃＡＭＰ的增加，而多潘立酮可阻断在Ｓｃｈ２３３９０存在下由ＰＢＤＡ引起的ｃＡＭＰ的降低．结论：长期应用多巴胺可使大鼠肾皮质的ＤＡ１和ＤＡ２受体均发生明显的“下调”，但余留受体的反应性不变．AIM: To study the effects of long term application of dopamine HCl (DA) on the functional changes of dopamine receptor subtypes coupled to adenyl cyclase in rat renal cortex. METHODS: cAMP levels were measured by radioimmunoassay as an index of dopamine receptor function. RESULTS: Injection of DA (30 mg·kg -1 ·d -1 , ip, 30 d) reduced the fenoldopam (Fen) (100 μmol·L -1 ) induced increments of cAMP production from the control group of +1 26±0 04 to the DA treated group of +0 63±0 22 nmol·min -1 /g tissue and the propyl butyl dopamine (PBDA) (100 μmol·L -1 ) induced decrements of cAMP production in the presence of Sch 23390 (Sch) from the control group of -0 38 ±0 18 to the DA treated group of -0 11±0 08 nmol·min -1 /g tissue with, however, comparable percentile changes for the 2 groups. Sch blocked both Fen and PBDA induced increase in cAMP production, while domperidone (Dom) blocked the decreasing effects of PBDA on cAMP accumulation in the presence of Sch. CONCLUSION: Long term application of DA produced a marked “down regulation” of both DA 1 and DA 2 receptors in rat renal cortex with, however, the responsiveness of the remaining receptors unchanged.

关 键 词：多巴胺 受体 肾皮质 CAMP 多潘立 

分 类 号：R971.93[医药卫生—药品]