血管紧张素转换酶和糜酶抑制剂对人脐静脉内皮细胞产生血管紧张素Ⅱ的影响

Effects of Angiotensin Converting Enzyme and Chymase on the Secretion of Angiotensin Ⅱ in Endothelial Cells in Human Umbilical Vein

目的 探讨血管紧张素转换酶和糜酶抑制剂对人脐静脉内皮细胞产生血管紧张素Ⅱ的影响。方法 培养的人脐静脉内皮细胞培养液中加入不同浓度开搏通和 /或糜酶抑制剂孵育 2 4小时 ,取上清液用放免法测定血管紧张素Ⅱ浓度。结果 10 -2 μmol/LAngⅠ使内皮细胞产生AngⅠ明显增加 ,约为对照组的 11.5倍。 10 0、10 0 0 μmol/L开搏通使AngⅡ的生成分别降低了 11.15 %和 17 0 6 %。 10 0、10 0 0 μmol/L糜酶抑制剂使AngⅡ的生成分别降低了6 0 2 3%和 6 8 4 8%。 1μmol/L抑肽酶使AngⅡ的生成降低了 13 96 %。氯沙坦使培养液中AngⅡ浓度略有升高。开搏通 +糜酶抑制剂使HUVEC产生AngⅡ减少 85 81% ,开搏通 +抑肽酶抑制 2 9 5 7%AngⅡ的生成 ,开搏通 +糜酶抑制剂 +抑肽酶几乎完全抑制HUVEC将AngⅠ转变成AngⅡ ,与AngⅠ组相比降低 97 71%。结论 人脐静脉内皮细胞存在ACE和非ACE途径AngⅡ生成 ,非ACE途径是主要的 ,影响非ACE途径血管紧张素Ⅱ生成的酶主要是糜酶抑制剂。

Objective To study the effects of angiotensin converting enzyme and chymase on secretion of angiotensin Ⅱ in the endothelial cells in human umibilical vein. Methods Cultured human umbilical vein endothelial cells (HUVEC) were incubated with captopril and chymostatin for 24 hours, the concentration of angiotensin Ⅱ in supernatant was measured using radio-immunology method. Results Ang Ⅱ increased about 11.5-fold in the presence of 10 -2 μmol/L Ang Ⅰ compared with control group. 100,1000 μmol/L captopril reduce Ang Ⅱ release by 11.15% and 17.06% respectively. 100,1000 μmol/L chymostatin reduce Ang Ⅱ generation by 60.23% and 68.48% respectively. 1 μmol/L aprotinin reduce Ang Ⅱ generation by 13.96% as compared with 10 -2 μmol/L Ang Ⅰ treated HUVEC. Losartan did not block Ang Ⅰ convert to Ang Ⅱ,on the contrary,the concentration of Ang Ⅱ increased slightly in the HUVEC culture supernatant. The generation of Ang Ⅱ reduced by 85.81% in the presence of captopril+chymostatin as compared with 10 -2 μmol/L Ang Ⅰ treated HUVEC. Captopril+aprotinin blocked 29.57% Ang Ⅱ generation. Captopril+chymostatin+aprotinin blocked Ang Ⅱ generation by 97.71%. Conclusion There are two angiotensin Ⅱ-production pathways in HUVEC: ACE-dependent and non-ACE-dependent pathway. Our data showed the non-ACE-dependent pathway was dominant in HUVEC.