| Background and ObjectiveSince the renin was found, the Basic Medicine had been researching the renin angiotensin system for nearly one century. The the renin angiotensin system (RAS) plays a important role in the atherosclerosis disease for its regulating effects in angiocardiopathy. We all know that the crisis factors of atherosclerosis disease include hypertention,diabetes mellitus, metabolic syndrome and so on. In those crisis the RAS is activated exceedingly, the improper proliferation of vascular smooth muscle cell (VSMC) boosts the progress of these diseases. angiotensin II (Ang II) is a major ingredient of the RAS, it plays its effect through the angiotensin 1 receptor. The local RAS can influences the function of vasculars and endothelial cells, the results are hypertention, atherosclerosis, vasculars remodeling and augment of VSMC number and their volume. The AngⅡcan upregulate the mRNA expression of proto-oncogenes and growth factors, also some hormones like Endothelin. The consequences are proliferation and hypertrophy of VSMC, meanwhile the extracellular matrix increases. on the other hand, The Ang II can upregulate the mRNA expression of nitric oxide synthase, nitric oxide can down regulate the expression of Bcl-2 and up regulate the expression of Bax, P53 and Fas in VSMC. the result is inhibiton to the proliferation of VSMC. In patients with pathological conditions the balance is broken, The VSMC behaves as proliferation and hypertrophy, its response to the vaso-activesubstances is upregulated, this makes the vascular wall thicker. The apoptosis of VSMC is regulated by much genes on the numerator level, by now the bcl - 2,p53,c-myc,Fas are studied much more for their relations with the apoptosis of VSMC cell. These genes play their effects throgh different signals conduct pathes. RAS is activated in AS patients, the RAS blockers are the basic medicine in therapy. At present the clinical research about RAS blockers are limited at the blood pressure control and remodeling of heart, the influences of RAS blockers to the remodeling of vascular smooth muscle cell induced by their hypertrophy Have not been researched too much, this project studied the influences of Ang II to the expressions of Bcl-2 and Fas of VSMC in Wista rats, the intervene effects of angiotensin converting enzyme inhibitors Captopril and angiotensin II receptor 1 blocker Losartan to the pysiological action of AngⅡabove-mentioned are also studied. The purpose of our study is to quest more theories for the RAS blockers in the prevention and cure of AS.Methods1. Cultured thoracic aorta VSMC cells of Wista rats.1) Chose male Wista rats, breaking the neck to death, primary cultured the thoracic aorta VSMC; The explant attached method was applied for subculture of VSMC, cultured the cells to 5-10 generation, the VSMC would be applied to the next steps.2) Made semithin slices and thinest slices with the VSMC, Immunocytochemical staining was used to the specimen, then observed the slices under light microscope and electron microscope. to differentiate the cells.2. The VSMC were divide into groups randomly.1) In the control group, the VSMC were cultured with 0.5%FCS nutrient solution.2) Cultured the VSMC with different concentrations of AngⅡ(10-8,10-7,10-6,10-5和10-4 mol/L), then tested the expression of Bcl-2 and Fas with Flow Cytometer. Intervened the groups with Captopril (10-5 mol/L) and Losartan(10-5 mol/L), then repeated the test.3) Cultured the VSMC with different acting time of AngⅡ(12,24,48和72hours), then tested the expression of Bcl-2 and Fas with Flow Cytometer. Intervene the group with Captopril (10-5 mol/L) and Losartan(10-5 mol/L), then repeated the test.4) To detect the expressions of Bcl-2 and Fas with flow cytometry for each groupResults1. The influences of Ang II, Captopril and Losartan to the expression of Bcl-2 in VSMC.1) Culture the VSMC with different concentrations of AngⅡ,the expression of Bcl-2 in VSMC was up regulated gradually with dose-dependent style in certain scale. The expression was signally up regulated in all AngⅡgroups with different concentrations except the 10-8 mol/L group (P<0.01). the expression of Bcl-2 in VSMC was down regulated slightly only in the 10-4 mol/L group. When intervened with Captopril, Losartan, Captopril and Losartan used together, the expression of Bcl-2 in VSMC was down regulated obviously, compared the groups, among the AngⅡgroups with follow concentrations 10-7, 10-6,10-5 and 10-4 mol/L, the Bcl-2 was down regulated by 65.63%,54.3%, 52.67% and 65.01% (P<0.05 or P<0.01) in Captopril group. the Bcl-2 was down regulated by 41.88%,32.32%,39.62% and 48.25% (P<0.05 or P<0.01) in Losartan group. the Bcl-2 was down regulated by 54.08%,80.18%,75.33% and 80.72% (mean P<0.01) in Captopril and Losartan used together group. Among groups above-mentioned the expression of Bcl-2 in VSMC was most obviouslydown regulated in the last group.2) Cultured the VSMC with different acting time of AngⅡ,the expression of Bcl-2 in VSMC was up regulated gradually with time-dependent style in certain scale except 12 hours group. In 24,48 and 72 hours groups the expressions of Bcl-2 were 6.35±1.22,35.58±5.06,38.32±5.15 and 40.47±5.25 When intervened with Captopril, Losartan, Captopril and Losartan used together, the expression of Bcl-2 in VSMC was down regulated obviously, compared the groups, among the Ang II groups with follow acting time 24,48 and 72hours, the Bcl-2 was down regulated 54.30%,67.74%(mean P<0.05) and 71.6% (P<0.01) in Captopril group. the Bcl-2 was down regulated 32.32%,55.24% and 60.31% (mean P<0.05) in Losartan group. the Bcl-2 was down regulated 80.18%,80.19% and 81.76% (mean P<0.01) in Captopril and Losartan used together group. Among groups above-mentioned the expression of Bcl-2 in VSMC was down regulated faster and faster except the last group.2. The influences of Ang II, Captopril and Losartan to the expression of Fas in VSMC.1) Cultured the VSMC with different concentrations of AngⅡ, the expression of Fas in VSMC was down regulated obviously (P<0.05). Among the groups of 10-7,10-6,10-5 and 10-4 mol/L the expression of Fas were 4.27±0.64,3.55±0.08,5.56±0.44 and 6.02±0.35. When intervened with Captopril, Losartan, Captopril and Losartan used together, the expression of Fas in VSMC was up regulated obviously except the 10-7 mol/L group. compared the groups, among the AngⅡgroups with following concentrations 10-7,10-6,10-5 and 10-4 mol/L, the Fas was up regulated by 58.66%,66.66%,54.45% and 60.16%(mean P<0.05) in Captopril group. the expressions of Fas were up regulated by 53.36%,59.41%,44.46% and 52.71 (mean P<0.05) in Losartan group. the expressions of Fas were down regulated by 74.76%,75.95%,65.99% and 70.14%(mean P<0.01) in Captopril and Losartan used together group. Among groups above-mentioned the expression of Bcl-2 in VSMC was most obviously up regulated in the last group.2) Cultured the VSMC with different acting time of AngⅡ,the expression of Fas in VSMC was down regulated obviously(P<0.05)except 12 hours group. Among the groups of 24,48 and 72 hours groups the expressions of Fas were 4.55±0.08,4.92±0.15 and 4.76±0.12. When intervened with Captopril, Losartan, Captopril and Losartan used together, the expression of Fas in VSMC was up regulated obviously except the 12 hours group. compared the groups, among the groups with following Ang II acting time 24,48 and 72 hours, the expressions of Fas were up regulated by 66.66%,70.25% and 73.68%(mean P<0.01) in Captopril group. the the expressions of Fas were up regulated by 59.41%,62.86% and 68.62%(mean P<0.01) in Losartan group. the expressions of Fas were was down regulated by 773.1%,73.51% and 76.46% (mean P<0.01) in Captopril and Losartan used together group. Among groups above-mentioned the expression of Fas in VSMC was most obviously up regulated in the last group.Conclusion1. the expression of Bcl-2 in Wista rats VSMC was increased by angiotensin II with a time and dose dependen style.2. the expression of Fas in Wista rats VSMC was decreased by angiotensinⅡwithout obvious time and dose dependen style.3. Captopril and Losartan could inhibit the expression of Bcl-2 induced by angiotensinⅡ, this effect was most apparent in Captopril and Losartan used together group.4. Captopril and Losartan could increase the expression of Fas induced by angiotensinⅡ, this effect was most apparent in Captopril and Losartan used together group.Creative point1. Our study shows that AngⅡcan increase the expression of Bcl-2 in Wista rats VSMC with a dose and time dependent style. Meawhile ACEI- Captopril and AT1 receptor blocker Losartan can withstand the effects of AngⅡ. The conclutions above mentioned have not been reported at home. moderating effect of AngⅡto the apoptosis of VSMV, meanwhile we proved the influencing effect of ACEI and AT1 recepor blocker to the AngⅡ, such research is rare at home.2. Our study shows that AngⅡcan decrease the expression of Fas in Wista rats VSMC without obvious dose and time dependent style. Meawhile ACEI-CaDtoDril and AT1 receptor blocker Losartan can withstand the effects of AngⅡ. The conclutions above mentioned have not been reported at home.
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