论文部分内容阅读
目的:研究Ca2+转运通路对金雀异黄酮舒张大鼠脑血管作用的影响。方法:75只大鼠被随机分为3组,分别经由二甲亚砜、金雀异黄酮和酪氨酸磷酸化抑制剂A47处理基底动脉及Willis环血管。每组大鼠进一步划分成5个亚组,每个亚组用不同浓度的细胞外Ca2+处理,分为:0、0.6、1.2、1.8和3.6 m M Ca2+组。5-羟色胺诱导血管收缩。测定大鼠基底动脉管壁厚度与官腔周长的比值;荧光成像分析法测定血管平滑肌细胞细胞内Ca2+浓度;免疫印迹分析检测肌球蛋白轻链激酶(MLCK),蛋白质磷酸酶催化亚基1(PP1),肌凝蛋白磷酸酶目标亚基1(MYPT1)的表达来测定血管平滑肌细胞Ca2+敏感性。结果:金雀异黄酮和酪氨酸磷酸化抑制剂A47显著降低大鼠基底动脉管壁厚度与官腔周长的比值(P<0.01),Ca2+内流(P<0.01,P<0.05)及MLCK的表达(P<0.01);增加PP1和MYPT1的表达(P<0.01)。细胞外Ca2+与金雀异黄酮及酪氨酸磷酸化抑制剂A47有协同效应。硝苯地平和毒胡萝卜素可废除该效应。结论:低细胞外Ca2+水平增强了金雀异黄酮和酪氨酸磷酸化抑制剂A47的血管舒张作用。L型电压门控Ca2+通道(L-VGCC)和肌浆网Ca2+库(SR)参与交互效应。
AIM: To investigate the effects of Ca2 + transport pathways on cerebrovascular function induced by genistein in rats. Methods: Seventy five rats were randomly divided into three groups and treated with dimethylsulfoxide, genistein and tyrosine phosphorylation inhibitor A47 respectively to treat basilar artery and Willis vasculature. Each group of rats was further divided into 5 subgroups. Each subgroup was treated with different concentrations of extracellular Ca2 +, which were divided into 0, 0.6, 1.2, 1.8 and 3.6 m M Ca2 + groups. Serotonin induces vasoconstriction. The ratio of basilar artery wall thickness to the lumen length was measured by fluorescence imaging method. The intracellular Ca2 + concentration in vascular smooth muscle cells was determined by fluorescent imaging analysis. The expressions of myosin light chain kinase (MLCK), protein phosphatase catalytic subunit 1 PP1), myosin phosphatase target subunit 1 (MYPT1) expression in vascular smooth muscle cells to determine Ca2 + sensitivity. Results: Genistein and tyrosine phosphorylation inhibitor A47 significantly reduced the ratio of basilar artery wall thickness to the lumen length (P <0.01), Ca2 + influx (P <0.01, P <0.05) and MLCK (P <0.01), and increased the expression of PP1 and MYPT1 (P <0.01). Extracellular Ca2 + has a synergistic effect with genistein and tyrosine phosphorylation inhibitor A47. Nifedipine and thapsigargin abolished this effect. CONCLUSIONS: Low extracellular Ca2 + levels enhance the vasodilatation of genistein and tyrosine phosphorylation inhibitor A47. L-type voltage-gated Ca2 + channels (L-VGCC) and sarcoplasmic reticulum Ca2 + pool (SR) participate in the interaction effect.