肝星形细胞存在局部肾素-血管紧张素-醛固酮系统

Hepatic stellate cells may exist a local renin-angiotensin-aldosterone system

目的 明确肝星形细胞和永生肝星形细胞株HSC T6是否存在局部肾素 血管紧张素 醛固酮系统。方法 采用原位酶灌注法分离培养肝星形细胞 ,采用放射免疫法检测细胞中肾素活性、血管紧张素Ⅱ和醛固酮水平 ;采用紫外分光光度法测定血管紧张素转换酶活性 ,免疫组化法检测血管紧张素Ⅱ 1型受体的表达 ;RT PCR法检测肾素、血管紧张素原、血管紧张素转换酶、血管紧张素Ⅱ 1型受体、醛固酮合成关键酶CYPⅡB2mRNA的表达。结果 肝星形细胞和HSC T6中可检测到肾素活性、血管紧张素转换酶活性、血管紧张素Ⅱ和醛固酮 ;免疫组化结果显示二者均表达血管紧张素Ⅱ的 1型受体 ;两种细胞均可检测到上述除血管紧张素原以外的 4种基因mRNA表达。结论 肝星形细胞和HSC T6存在局部肾素 血管紧张素 醛固酮系统。

Objective The present study was to elucidate whether there was a local renin-angiotensin-aldosterone system (RAAS)in rat hepatic stellate cells(HSC)and the immortalized rat HSC line—HSC-T6. Methods HSC was isolated by perfusion of collagenase and pronase to liver. The renin activity, angiotensin Ⅱ(Ang Ⅱ) and aldosterone(ALD) concentration in the cells were assayed by radio-immunoassay. Angiotensin converting enzyme(ACE) activity was detected by ultra-violet spectrophotography. The expression of angiotensin Ⅱ type 1 receptor(AT1R) was determined by immunohistochemistry. RT-PCR method was used to assay the mRNA expression of renin, angiotensinogen, ACE, AT1R and CYPⅡB2(the critical enzyme of aldosterone synthesis). Results Ang Ⅱ, ALD, renin and ACE activity could be detected in HSC and HSC-T6. Immunohistochemistry showed that both of them could express AT1R. mRNAs of renin, ACE, AT1R and CYPⅡB2 were also detected in both of them. Conclusions Both rat HSC and the immortalized rat HSC line HSC-T6 possessa a local RAAS.