β受体亚型在人心房成纤维细胞增殖分泌中的作用

目的通过肾上腺素能受体激动剂和拮抗剂干预体外培养的人心房成纤维细胞，研究β受体在成纤维细胞增殖分泌中的作用及机制。方法：取体外循环患者右心耳组织行成纤维细胞分离培养、鉴定。实验分4组，对照组（CON组）、异丙肾上腺素组（ISO组）、ISO＋阿替洛尔组（ISO＋ATE组）、ISO＋卡维地洛组（ISO＋CAR组）；干预后检测上清液中羟脯氨酸含量、细胞增殖、β受体mRNA及pPKAR2蛋白的表达。结果：1，ISO＋CAR组和ISO组的细胞增殖率分别为11-3％和33．8％，P〈0．01；其上清液中羟脯氨酸含量分别为6．32±1．30“g／ml和8．68±1．80μg／ml，P〈0．01；2，D受体亚型mRNA的表达：p2AR／GAPDH在IsO＋CAR和ISO组分别为0．52和066，P〈0．0l；而ATE＋ISO组和ISO组分别为：0．63和0．66，P〉0．05。3，pPKA蛋白表达：ISO＋CAR组同ISO组相比，pPKAR2／D．actin分别是0．60和0．81，P〈0．01。结论：ISO能刺激体外培养的人心房成纤维细胞增殖和分泌胶原；非选择性B受体拮抗剂卡维地洛可抑制成纤维细胞增殖及分泌，其机制与D2AR-pPKAR2途径有关。

The mechanism of beta adenoreceptor in proliferation and secretion of human atrial fibroblast

Aim The purpose of this study was to determine whether beta adenoreceptor inhibitor effects proliferation and secretion of human atrial cardiac fibroblast(haCF) and investigate the mechanism involved by culturing haCF from right atrial appendage(RAA).Methods:In vitro culture of haCF was established from biopsies of RAA and identificated by immunohistochemistry.The expression of beta adenoreceptor’s mRNA was detected by RT-PCR analysis.All samples were divided into four groups,serum control group(CON),isoproterenol group(ISO),isoproterenol and atenolol group(ISO+ATE),isoproterenol and carvedilol group (ISO+CAR).After the interventions,the followings were tested:the hCF cell proliferation detected by the MTT method,hydroxyproline by the sample alkaline hydrolysis methods,and the expression of pPKAR2 detected by western-blot.Results:1,ISO induced a concentration-dependent increase in proliferation of haCF.In ISO+CAR group,the cell proliferation and hydroxyproline in supernatant were lower than those in ISO group,the value was 11.3% vs 33.8%,P<0.01;6.32±1.30ug/ml vs 8.68±1.80ug/ml,P<0.01,respectively.2,The expression of mRNA of beta2 adenoreceptor(β2AR) in ISO+CAR group was lower than that in ISO group,the value of β2AR/GAPDH was 0.52 vs 0.66,P<0.01.The value of ATE+ISO and ISO was 0.63 vs 0.66,P>0.05.3,The expression of pPKA R2 in ISO+CAR group was lower than that in ISO group,and the value of pPKA R2/β-actin was 0.60 vs 0.81,P<0.01.Conclusion:ISO can induce a concentration-dependent increase in hCF proliferation and secretion of collagen in haCF.Carvedilol,a non selectiveβ2-AR antagonist,can inhibit the cell proliferation and secretion of collagen in haCF,through the mechanism of β2AR-pPKA R2 pathway.