Protective effect of tanshinone ⅡA on vasoactive substances induced by angiotensin Ⅱ in cultured porcine aortic endothelial cells

Yongsheng LI; Zhaohua WANG; Qiansheng LIANG; Zhi ZHENG

ABSTRACT

BACKGROUND:

Among the factors causing vascular endothelial cell injury,angiotensin Ⅱ(Ang Ⅱ) caused by renin-angiotensin system (RAS), especially by local RAS, plays an important patho-physiological role.

OBJECTIVE:

To observe the effect of tanshinone ⅡA on the vascular endothelial cells secreting nitric oxide (NO) and endothelial nitric oxide synthase (eNOS) gene expression as well as intracellular Ca2+ level induced by Ang Ⅱ, and investigate the protective effect of tanshinone ⅡA on vascular endothelial cells.

DESIGN:

Controlled observation experiment.

SETTING:

Department of Emergency, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology.MATERIALS This experiment was carried out in the Experimental Center for Basic Medicine, Tongji Medical College,Huazhong University of Science and Technology from March 2006 to October 2006. Porcine aorta used in this experiment was provided by the Department of Pathophysiology of Tongji Medical College.

METHODS:

Nitric acid deoxidization method and reverse transcription-polymerase chain reaction (RT-PCR) were used to detect the effects of Ang Ⅱ of different concentrations (10-8 to 10-6 mol/L) on endothelial cells secreting NO and eNOS mRNA expression in cultured porcine aortic endothelial cells at different time points (1,6 and 24 hours) separately, then 50 mg/L tanshinone Ⅱ A was respectively added at different time point (0, 6 hours) when Ang Ⅱ was at 10-6 mol/L, and changes in NO production and eNOS gene expression were detected respectively at 1, 6 and 24 hours. Intracellular Ca2+ level was also detected with laser scanning confocal microscopy.MAIN OUTCOME

MEASURES:

① NO content. ②eNOS mRNA expression. ③Intracellular Ca2+ level.

RESULTS:

① NO production and eNOS mRNA expression were decreased with increase of Ang Ⅱ concentration and prolongation of time (P ＜ 0.01). ② NO production and eNOS mRNA expression in each tanshinone ⅡA-treated group were significantly higher than those in the Ang Ⅱ group. At 1 and 6 hours of tanshinone ⅡA treatment, production of NO and eNOS mRNA expression in the Ang Ⅱ + tanshinone ⅡA group were significantly higher than those in the Ang Ⅱ 6 hours + tanshinone ⅡA group (P ＜ 0.05); There were no significant differences in NO production and eNOS mRNA expression between two groups at 24 hours (P ＞ 0.05). ③Intracellular Ca2+ level in the Ang Ⅱ group was significantly higher than that of control group (P ＜ 0.01), and intracellular Ca2+ level in the tanshinone ⅡA + Ang Ⅱ was significantly lower than that in the Ang Ⅱ group (P ＜ 0.05).

CONCLUSION:

Tanshinone Ⅱ A has a protective effect on vascular endothelial cells and their functions by suppressing the inhibition of Ang Ⅱ on NO level and eNOS gene expression in cultured porcine aortic endothelial cells.