P物质对体外培养大鼠心肌细胞β1-肾上腺素能受体表达下调作用的研究

目的 观察P物质(SP)对体外培养新生大鼠心肌细胞β1-肾上腺素能受体(β1-AR)表达的影响.方法 选择出生1～3 d的SD大鼠.分离、培养心肌细胞,将细胞培养至72 h待用.用6孔培养板将细胞随机分为对照组与10-7mol/L SP组,每组3孔;采用免疫细胞化学技术测定心肌细胞中β1-AR的表达.另取15孔培养板将细胞随机分为对照组(不加药物干预)与SP组(分别给予10-9、10-8、10-7、10-6mol/L SP干预),每组3孔;采用流式细胞术测定心肌细胞膜表面β1-AR的表达.结果 免疫细胞化学结果显示,SP组心肌细胞β1-AR阳性单位和平均吸光度(A)值均低于对照组(阳性单位:179.61±48.18比205.79±117.42,A值:128.26±22.72比157.35±33.11,P均<0.05).流式细胞术结果显示,不同浓度SP组β1-AR表达均低于对照组.除10-9mol/L SP组(158.87±3.12)外,10-8、10-7、10-6mol/L SP组与对照组比较差异有统计学意义(151.85士4.63,135.00±6.84,121.41±5.22比161.35±3.09,P均<0.05),且呈剂量依赖性.结论 SP可以抑制体外培养大鼠心肌细胞β1-R的表达.

Effect of substance P on expression of β1-adrenergic receptor in cultured rat cardiomyocytes

Objective To investigate the effect of substance P (SP) on expression of β1-adrenergic receptor (β1-AR) in cultured neonatal rat cardiomyocytes. Methods Cardiomyocytes were obtained from 1- 3 days old Sprague-Dawley (SD) rats and cultured for 72 hours. Six wells of the cultured cells were divided into two groups (n= 3 in each group): control group and SP group (incubated with 10-7 mol/L of SP). Immunocytochemistry was used to detect the expression of β1-AR in cultured rat cardiomyocytes. Fifteen wells of the cultured cells were divided into five groups (n=3 in each group): control group and four SP groups (incubated with 10-9, 10-8, 10-7, 10-6 mol/L of SP respectively). Quantitative analysis of the expression of β1-AR in cultured neonatal rat cardiomyocytes of all the groups was performed using flow cytometry. Results The results of immunocytochemistry showed that the expression of β1-AR in cardiomyocytes in SP group was lower than that in control group (positive unit: 179.16 ± 48. 18 vs. 205.79±117. 42, average light density: 128. 26±22. 72 vs. 157.35±33. 11, both P<0. 05). The results of flow cytometry showed that significantly lower levels of expression of β1-AR were observed in the groups treated with SP in the concentrations ranging from 10-8 mol/L to 10-6 mol/L (151.85± 4.63, 135.00±6.84, 121.41±5.22 vs. 161.35±3.09, all P<0. 05). Conclusion SP could down-regulate the expression of β1-AR in cultured rat cardiomyocytes in vitro.