多巴胺受体对牛眼小梁细胞环磷酸腺苷的调节作用

The regulating effects of dopamine receptors on the level of adenosine 3,5cyclic monophosphate in bovine trabecular cells in vitro

目的分析多巴胺（ｄｏｐａｍｉｎｅ，ＤＡ）能激动剂和拮抗剂对牛眼小梁细胞内环磷酸腺苷的调节作用。方法运用蛋白竞争结合法用氚（Ｈ３）标记的环磷酸腺苷（ａｄｅｎｏｓｉｎｅ３，５ｃｙｃｌｉｃｍｏｎｐｈｏｓｐｈａｔｅ，ｃＡＭＰ）测定牛眼小梁细胞内ｃＡＭＰ的含量。结果（１）ＤＡ受体激动剂ＤＡ和ＤＡ１受体激动剂诺非泮尔可使牛眼小梁细胞内ｃＡＭＰ含量成倍增加。（２）ＤＡ和诺非泮尔的这种作用可被非选择性ＤＡ受体拮抗剂氟哌丁苯和选择性ＤＡ１受体拮抗剂ＳＣＨ２３３０９有效拮抗，而不被α受体拮抗剂酚苄明和β受体拮抗剂噻吗心安拮抗。结论牛眼小梁细胞上不仅存在β受体，且亦存在ＤＡ１受体。

Objective To assay the regulating effects of dopaminergic agonists and antagonists on adenosine 3,5cyclic monophosphate (cAMP) level in bovine trabecular cells (BTC) in vitro. Method H3cAMP was used in protein binding assay to determine the level of cAMP in bovine BTC. Results Dopamine, a dopamine receptor agonist, and fenoldopam, a selective DA1 receptor agonist, caused a fold increase of cAMP in cultured BTC in vitro. These effects were blocked by halporide, a nonselective dopamine antagonist, and SCH23309, a selective DA1 antagonist, but not blocked by phenoxybenzamin, an αadrenergic antagonist, and timolol, a βadrenergic antagonist. Conclusion Bovine trabecular cells contain not only βreceptors but also DA1 receptors.