摘要
目的明确大鼠肝星状细胞是否表达肾素血管紧张素醛固酮系统(RAAS)的全部成分及其在肝星状细胞激活过程中的变化;观察血管紧张素Ⅱ对肝星状细胞合成RAAS的反馈调节作用;探讨依那普利和氯沙坦对此系统的抑制作用。方法采用原位酶灌注法分离大鼠肝星状细胞,分别在培养第2、4、7天收集上清液,传代细胞用无血清培养,并用不同浓度依那普利和氯沙坦进行干预。采用放射免疫法检测上清液和细胞裂解液中肾素活性、血管紧张素Ⅱ和醛固酮浓度,紫外光法检测血管紧张素转换酶活性,免疫组织化学法检测血管紧张素Ⅱ受体表达,RTPCR法检测RAAS各成分mRNA表达。结果肝星状细胞表达RAAS所有成分mRNA。在肝星状细胞培养上清液中可检测到肾素活性(0.56±0.23)ng·h-1·106细胞-1。血管紧张素Ⅱ(48.79±14.54)pg105细胞和醛固酮(22.75±4.35)pg105细胞,并随肝星状细胞激活升高。依那普利可抑制肝星状细胞表达RAAS;血管紧张素Ⅱ能正反馈调节星状细胞表达RAAS,这种作用可被氯沙坦阻断。结论大鼠肝星状细胞能表达RAAS,并随其激活而升高。RAAS具有自身正反馈调节作用,可被依那普利和氯沙坦阻断。
Objective To detect the expression of the components of renin-angiotensin aldosterone system (RAAS) of hepatic stellate cells(HSCs) and it's change during activation of HSC, to observe the feedback regulation of RAAS and the effects of enalapril and losartan on it.Methods HSC were prepared by pronase-collagenase method. The culture medium was colleced at the 2 nd ,4 th ,7 th day of primary culture. After the second culture, HSC were incubated with different concentrations of angiotensin Ⅱ enalapril or losartan for 24 hours, then the medium and cells were collected. Renin activity, angiotenin Ⅱ and aldosterone were determined by radio-immunoassay. Angiotensin converting enzyme(ACE) activity was determined by ultra-violet spectrophotography. mRNA expression of the components of RAAS was detected by RT-PCR. Expression of angiotensin Ⅱ receptors was detected by immunohistochemical technique.Results HSC expressed mRNA of renin, angiotensinogen, ACE, CYP11B2 and angiotesin Ⅱ receptor type I. Renin activity, ACE activity, angiotensin Ⅱ and aldosterone in the culture medium could be detected and increased with activation of HSC.Condusion HSC can experess RAAS, and the level of RAAS is increased with activation of HSC. RAAS has the role of feedback regulation, which can be inhibited by enalapril or losartan.
出处
《肝脏》
2005年第2期86-88,共3页
Chinese Hepatology
