牛磺酸对肾血管性高血压大鼠左室肥厚的保护作用

Effects of taurine on left ventricular hypertrophy in renovascular hypertensive rats

目的 观察牛磺酸 (Tau)对肾血管性高血压大鼠左室肥厚的影响 ,并探讨其机制。方法 建立二肾一夹 (2K1C)肾动脉狭窄性高血压模型。羟脯氨酸法测定大鼠心肌胶原含量 (MCC) ;放免法测定心肌AngⅡ (MAC)及Ald(MDC) ;原位杂交方法检测c fosmRNA表达 ;显微镜观察心肌组织结构改变并测量心肌纤维直径 (MFD) ,并进行线性相关分析。结果 2K1C组大鼠MCC、MAC、MDC含量及MFD较Sham组增加 (P <0 0 1) ,c fosmRNA表达高于Sham组 (P<0 0 1) ;心肌冠状动脉周围胶原纤维大量增生并向周围间质延伸 ;相关分析显示MCC及MFD皆与MAC、MDC正相关 (P <0 0 1)。牛磺酸 (5 0mg·kg-1·d-1)治疗 8wk降低2K1C大鼠尾动脉收缩压 (SBP)、MAC、MDF及MCC(P <0 0 1) ,左心室 /体重比 (LVWI)、MDC及心室肌c fosmRNA表达量亦明显下降 (P <0 0 1) ,并抑制心肌冠脉周围胶原纤维增生。结论 牛磺酸可通过降低心肌局部RAAS活性及c fosmRNA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左室肥厚。

AIM To investigate the preventive effects of taurine on the left ventricle hypertrophy in renovascular hypertensive rats. METHODS Two-kidney 1-clip (2K1C) rats were used to establish the model of renovascular hypertension. The myocardial local aldosterone(Ald) and AngⅡconcentration (MDC,MAC) were measured by radioimmunoassay. Expression of oncogene c-fos mRNA was analyzed by means of in situ hybridization. The myocardial collagen concentration (MCC) was measured by biochemical method. The myocardial tissue structure was observed under the microscope ,and the myocardial fiber diamension (MFD) was measured with micrometer. The linear correlation between MCC, MFD and MAC or MDC was analysed respectively. RESULTS Compared with sham operated rats ,the MCC, MAC, MDC and MFD were significantly increased in 2K1C rats ( P< 0.01).Expression of oncogene c-fos mRNA was also obviously higher than sham group( P< 0.01). Collagenous fiber productive reaction occurred in the circumference of the coronary artery and stretehed to periphery interstitial. Both MCC and MFD positively correlated with MAC and MDC respectively ( P< 0.01). Taurine has an obviously suppressive effect on SBP, MAC, MFD ,MCC,LVWI , MDC c-fos mRNA expression( P< 0.01 for all these indices), myocardial cell hypertrophy and collagenous fiber productive reaction in 2K1C rats. CONCLUSION Taurine which effectively suppress myocardial cell hypertrophy and collagenous fiber productive reaction by decreasing myocardial local RAAS and c-fos mRNA expression can produce good preventive effect on left ventricle hypertrophy caused by renal hypertension