自发性高血压大鼠主动脉平滑肌细胞内胞浆游离钙浓度及氯沙坦治疗后的变化

Effects of losartan on intracellular free calcium concentration of aortic smooth muscle cells in spontaneously hypertensive rats

目的 观察自发性高血压大鼠 (SHR)和正常血压对照鼠 (WKY)主动脉平滑肌细胞 (SMC)内胞浆游离钙浓度 ([Ca2 + ] i)与氯沙坦治疗后的变化 ,探讨 [Ca2 + ] i 在氯沙坦降压中的作用。方法 治疗前组 :SHR ,10只 ;氯沙坦治疗组 :SHR ,7只 ;正常对照组 :WKY ,7只。其中氯沙坦治疗组饲氯沙坦 2 0mg/(kg·d) ,连续 6个月。上述 3组大鼠均检测鼠尾动脉收缩压 ,进行SMC培养 ,检测SMC培养细胞内 [Ca2 + ] i。结果 治疗前组SHR鼠尾动脉收缩压及SMC内[Ca2 + ] i显著高于WKY(P <0 0 0 1) ,经氯沙坦 6个月治疗后 ,SHR鼠尾动脉收缩压及SMC内 [Ca2 + ] i 显著下降 (P <0 0 1)。鼠尾动脉收缩压的下降幅度和SMC内 [Ca2 + ] i 的下降幅度呈正相关 (r =0 65 3 ,P <0 0 5 )。结论 SHR的SMC内存在钙代谢紊乱 ,氯沙坦通过纠正细胞内钙代谢异常而达到降压的目的。

Objective To investigate the effects of losartan on intracellular free calcium concentration of aortic smooth muscle cells in spontaneously hypertensive rats(SHR).Methods Normotensive control Wistar-Kyoto (WKY) rats and SHRs were used in the study, SHRs were devided into two groups: pre-treatment groups and losartan-treatment group [20 mg/(kg·d)]. Blood pressure and intracellular free calcium concentration ([Ca 2+ ] i) of cultured aortic smooth muscle cells(SMC) were measured. Results Blood and intracellular [Ca 2+ ] i of cultured SMC in SHR were significantly higher than that of WKY( P < 0.001 ). After 6 months of losartan treatment, blood pressure and [Ca 2+ ] i of cultured SMC were significantly reduced( P <0 01). There was a positive correlation between the changes of blood pressure and [Ca 2+ ] i of cultured SMC ( r=0 653, P<0 05 ).Conclusion There is disturbance of intracellular calcium metabolism in SHR. Antihypertensive effect of losartan may be associated to normalization of intracellular calcium metabolism.