Wu Yang, Gu Yu-mei
Institute of Navigation Medicine, Natong University, Natong 226001, China.
Zhongguo Ying Yong Sheng Li Xue Za Zhi. 2007 May;23(2):138-42.
To investigate the effect of extract of ginkgo biloba (EGb) and quercetin (Que) on the hypertrophic response induced by angiotensin II (Ang II) in the primary culture of neonatal rat cardiomyocytes and its mechanism.
Total protein content of cardiomyocytes was measured by lowry's method. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were measured by SOD and MDA assay kits. The expression of phospho-ERK1/2, phospho-JNK and phospho-P38 were detected by Western blot. The expression of c-fos mRNA was checked by RT-PCR.
(1) The total protein content and cell size of cardiomyocytes increased significantly after Ang II treatment, EGb and Oue inhibited these effects of Ang II. (2) EGb and Que were able to enhance the SOD activity and reduce the production of MDA. (3) Ang II significantly activated ERK1/2, JNK and P38, only JNK activation was inhibited by Que and DPI but not ERK1/2 and P38 activation. (4) EGb, Que, Captopril and DPI all decreased Ang II-stimulated early response gent c-fos mnRNA expression.
EGb and Que could inhibit AngII-induced cardiomyocyte hypertrophy through a ROS-dependent pathway, the effect of Que might be related to the JNK and c-fos cascade.
研究银杏叶提取物（EGb）和槲皮素（Que）对新生大鼠心肌细胞原代培养中血管紧张素II（Ang II）诱导的肥大反应的影响及其机制。
采用洛氏法测定心肌细胞总蛋白含量。用超氧化物歧化酶（SOD）和丙二醛（MDA）检测试剂盒测定SOD活性和MDA含量。通过蛋白质免疫印迹法检测磷酸化ERK1/2、磷酸化JNK和磷酸化P38的表达。通过逆转录聚合酶链反应（RT-PCR）检测c-fos mRNA的表达。
（1）Ang II处理后心肌细胞总蛋白含量和细胞大小显著增加，EGb和Que可抑制Ang II的这些作用。（2）EGb和Que能够增强SOD活性并减少MDA的产生。（3）Ang II显著激活ERK1/2、JNK和P38，只有JNK的激活被Que和二苯基碘（DPI）抑制，而ERK1/2和P38的激活未被抑制。（4）EGb、Que、卡托普利和DPI均降低了Ang II刺激的早期反应基因c-fos mRNA的表达。
EGb和Que可通过活性氧（ROS）依赖的途径抑制Ang II诱导的心肌细胞肥大，Que的作用可能与JNK和c-fos级联反应有关。
