替米沙坦对血管紧张素Ⅱ所致血管内皮细胞游离钙离子的抑制作用

The inhibitory effect of Telmisartan on vascular endothelium cells free calcium induced by angiotensinⅡ

目的探讨血管紧张素Ⅱ(AngⅡ)对细胞钙库的应激效应及替米沙坦对此的拮抗作用。方法预防性实验分组:正常对照组、AngⅡ0.1μmol/L组和替米沙坦60、300、1000μg/L预处理组;治疗性实验分组:正常对照组、AngⅡ0.1μmol/L组和AngⅡ+替米沙坦60、300、1000μg/L组。分别检测各组试验前胞内钙离子浓度,记为0 h。体外培养的人大动脉血管内皮细胞预防性给予替米沙坦60、300、1000μg/L培育30 min后,加入AngⅡ0.1μmol/L;或AngⅡ0.1μmol/L培育30 min后,再加入替米沙坦60、300、1000μg/L,分别于共同作用0.5、2、8和24 h采用激光共聚焦扫描显微镜成像法检测胞浆游离钙离子浓度。结果预防性实验:与正常对照组相比,替米沙坦60、300、1000μg/L作用细胞30 min对胞浆游离钙离子浓度无明显影响,加入AngⅡ0.1μmol/L后,胞浆游离钙离子浓度立即(0 h)显著升高,均显著高于正常对照组(P<0.05),但显著低于AngⅡ组,并且替米沙坦预处理浓度越高抑制作用越强(P<0.05),作用时间对此无影响。治疗性实验:AngⅡ0.1μmol/L先诱导30 min后,再加入替米沙坦60μg/L对升高的胞浆游离钙离子浓度无抑制作用;替米沙坦300μg/L作用2 h或替米沙坦1000μg/L作用0.5 h才显示其抑制作用(P<0.05),但均显著高于同一时间点的正常对照组。替米沙坦的作用时间对此无影响。结论 AngⅡ能诱导内质网钙库向胞浆释放游离钙离子,而替米沙坦能有效拮抗AngⅡ对内质网的应激作用及促使胞浆游离钙离子重新被内质网重吸收。预防性给予替米沙坦的拮抗作用较治疗性给予的拮抗作用显著。

Objective To explore the effect of angiotensin（Ang） Ⅱ on intracellular free calcium concentration in vascular endothelial cell（VEC） and antagonism of Telmisartan. Methods Preventive test： control group; AngⅡ 0.1 μmol/L group; 60, 300 and 1000 μg/L Telmisartan groups. Therapeutic test： control group; Ang Ⅱ 0.1 μmol/L group; 60, 300 and 1000 μg/L Telmisartan＋AngⅡ groups. Intracellular calcium concentration was detected in each groups before the tests and the time were denoted 0 h. VECs co-cultured with 60, 300 and 1000 μg/L Telmisartan separately as prevention and increased Ang Ⅱ 0.1 μmol/L after 30 min; or VECs co-cultured with Ang Ⅱ 0.1 μmol/L and increased 60,300 and 1000 μg/L Telmisartan separately after 30 min. Then, concentration of intracellular free calcium concentration in VEC was scanned by laser scanning confocal microscope on certain point time when VECs were co-cultured 0.5, 2,8 and 24 h. Results Preventive test： compared with the control group, VECs pre-co-cultured with 60, 300 and 1000μg/L Telmisartan 30 min separately has no discernible effect on VEC＇s intracellular free calcium concentration. But after increasing Ang Ⅱ 0.1 μmol/L, concentration of intracellular free calcium climbed significantly instantaneously,which were higher than control group（P 〈0.05）, but lower than the groups which never pretreated with Telmisartanand preformed dose-response relationship characters.Therapeutic test： VECs were pretreated with Ang Ⅱ 0.1μmol/L showed Telmisartan preformed resistance after 2 h with 300 μg/L and 0.5 h with 1000 μg/L（P 〈0.05）. But60 μg/L Telmisartan had no discernible effect on VEC＇sintracellular free calcium concentration. In both experiment, time have no much effect on the results. Conclusion AngⅡ can induce endoplasmic reticulum calcium store release free calcium to the cytoplasmic. Telmisartan can antagonize the stress effect on endoplasmic reticulum caused by Ang Ⅱ and promote the intracellular free calcium ion re-reabsorption by the endoplasmic reticulum. Effects of resistance of Telmisartan on pretreatment as prevention is higher than those on treatment as therapy.