Rho/Rho激酶在压力负荷心力衰竭大鼠心肌组织的表达

目的　探讨升主动脉缩窄压力超负荷心力衰竭 (心衰 )大鼠心肌组织Rho/Rho激酶的表达及Rho激酶抑制剂法舒地尔 (fasudil)对心衰的影响。方法　结扎大鼠升主动脉 ,同时制备假手术模型。 2 0周后成功建立慢性心衰模型。随机分为三组 ,每组 10只大鼠 :(1)假手术组 :生理盐水 0 1ml,腹腔注射 ,每日 2次 ;(2 )心衰组 :生理盐水 0 1ml,腹腔注射 ,每日 2次 ;(3)fasudil组 :fasudil 5mg/kg ,腹腔注射 ,每日 2次 ,疗程 4周。治疗前后检测各组大鼠血流动力学指标 ,疗程结束后处死大鼠 ,检测左室肥厚指数、心肌组织RhoA、Rho激酶mRNA表达及Ca2 + 浓度即 [Ca2 + ]i 的变化。结果心衰组与假手术组相比 ,左室舒张末压明显增高 ,而左室收缩压和左室压力变化最大上升和下降速率明显减低 ,P <0 0 1;左室肥厚指数明显增加 ,P <0 0 1;心肌组织RhoA、Rho激酶mRNA表达显著增高 ,P <0 0 1;心肌组织内 [Ca2 + ]i 显著增高 ,P <0 0 1。fasudil组与心衰组相比 ,左室舒张末压明显减低 ,左室收缩压和左室压力变化最大上升和下降速率明显增高 ,P <0 0 1;左室肥厚指数下降 ,P <0 0 1;心肌组织RhoA、Rho激酶mRNA表达明显下降 ,P <0 0 1;心肌细胞内 [Ca2 + ]i 变化无统计学意义 ,P >0 0 5。结论　心衰大鼠心肌组织RhoA、Rho激

The expression of Rho/Rho kinase of cardiac muscle in heart failure rats caused by pressure overload and the intervention of fasudil

OBJECTIVE: To study the expression of Rho/Rho kinase of cardiac muscle in heart failure rats caused by pressure overload and the effects of fasudil on heart failure. METHODS: The heart failure models were successfully induced by coarctation of ascending aorta after 20 weeks in this study. Thirty female Wistar operated rats were divided randomly into three groups (n = 10) for 4 week treatment. (1) Sham operation group: normal saline, 0.1 ml, i.p,Bid. (2) Heart failure group: normal saline, 0.1 ml,i.p,Bid. (3) Fasudil group: fasudil 5 mg/kg, i.p, Bid. The hemodynamic parameters, the ratio of LV weight to body weight, the expressions of RhoA and Rho kinase mRNA, and the concentration of calcium ion same as [Ca(2+)](i) were investigated in the three groups. RESULTS: Hemodynamic parameters were significantly changed in heart failure group than those in sham operation group, such as left ventricular diastolic end pressure increased [(13.00 +/- 0.30) mm Hg vs (3.78 +/- 0.31) mm Hg, P < 0.01], left ventricular systolic pressure decreased [(97.20 +/- 7.21) mm Hg vs (129.45 +/- 7.52) mm Hg, P < 0.01]. Those results could be significantly changed by use of fasudil, P < 0.01. The ratio of LV weight to body weight was significantly increased in heart failure group than that in sham operation group [(4.77 +/- 0.08) mg/g vs (2.51 +/- 0.12) mg/g, P < 0.01]. Fasudil could significantly decrease the ratio of LV weight to body weight compared with that in heart failure group [(4.05 +/- 0.08) mg/g vs (4.77 +/- 0.08) mg/g, P < 0.01]. Cardiac muscle RhoA, Rho kinase mRNA level and [Ca(2+)](i) were higher in heart failure group than those in sham operation group [Ca(2+)](i) (475.93 +/- 28.22) nmol/L vs (79.25 +/- 3.33) nmol/L, P < 0.01. Compared with those in heart failure group, the expressions of RhoA, Rho kinase mRNA level decreased significantly, P < 0.01, and the levels of cardiomyocyte [Ca(2+)](i) had no change in fasudil group [(462.78 +/- 16.72) nmol/L vs (475.93 +/- 28.22) nmol/L, P > 0.05]. CONCLUSIONS: These results indicated that heart failure was probably related to activating of RhoA, Rho kinase. Fasudil may contribute to the observed beneficial effects on heart failure such as the decrease of RhoA, Rho kinase mRNA expression and not increase of [Ca(2+)](i) level. Rho/Rho kinase may be a novel, potent signaling of heart failure.