牛磺酸对肾性高血压大鼠肥厚心肌原癌基因c-fos表达的影响

 目的观察牛磺酸(taurine,Tau)对肾血管性高血压大鼠肥厚心肌原癌基因c-fos表达的影响。方法建立二肾一夹(2K1C)肾动脉狭窄性高血压大鼠模型。羟脯氨酸法测定大鼠心肌胶原含量(myocardial collagen concentration,MCC);放免法测定心肌血管紧张素Ⅱ含量(myocardial local AngⅡconcentration,MAC)及醛固酮含量(myocardial local aldosterone concentration,MDC); 免疫组化方法检测c-fos蛋白表达,原位杂交方法检测c-fos mRNA表达。结果2K1C组大鼠尾动脉收缩压(systolic blood pres sure,SBP)、左心室/体重比(left ventricular weight index,LVWI),MCC,MAC及MDC较sham组显著增加(P<0.01);MCC与心肌MAC,MDC显著正相关(r=0.832 3,0.901 9,P<0.01);c-fos蛋白及c-fos mRNA表达高于sham组(P<0.01);Tau(50 mg·kg^-1·d^-1,ig×8周)显著降低2K1C大鼠SBP,LVWI,MCC,MAC,MDC,心室肌c-fos mRNA及蛋白表达量亦明显下降(P<0.01)。结论Tau可通过降低心肌局部肾素-血管紧张素-醛固酮系统(renin-angiotension-aldosterone system,RAAS)活性及c-fos表达,从而抑制心肌细胞肥大及胶原纤维增生,有效防治肾血管性高血压心肌肥厚。

Effects of taurine on expression of proto-oncogene c-fos in left ventricular hypertrophy in renovascular hypertensive rats

OBJECTIVE To investigate the effects of taurine on the expression of proto-oneogene c-fos in the left ventricular hypertrophy in renovascular hypertensive rats. METHODS Two-kidney 1-clip (2K1C) rats were used to reestablish the model of renovascular hypertension. The myocardial collagen concentration (MCC) was measured by biochemical method. The myocardial local aldosterone(Ald) and Ang Ⅱ concentration (MDC, MAC) were measured by radioimmunoassay. The expression of c-fos protein was measured by immanohistochemical method. The expression of proto-oncogene c-fos mRNA was analyzed by means of in situ hybridization. RESULTS Compared with sham operated rats, the systolic blood pressure(SBP), left ventricular weight index (LVWI), MCC, MAC and MDC were significantly increased in 2K1C rats (P<0.01). MCC was positively correlated with MAC and MDC, respectively(r=0.8323, 0.9019,P<0.01). The expressions of oncogene c-fos mRNA and protein were also obviously higher than that in sham group(P<0.01). Taurine(50 mg·kg^-1·d^-1,ig×8weeks) had an obvious suppressive effect on SBP, LVWI, MCC, MAC, MDC and the expression of proto-oncogene c-fos mRNA and protein(P<0.01 for all these indices). CONCLUSION By suppressing myocardial local RAAS and proto-oncogen c-fos expression, taurine can produce good preventive effect on left ventricle hypertrophy caused by renal hypertension.