辣椒素对自发性高血压大鼠CD36和Ⅰ、Ⅲ型胶原表达的影响

Effect of capsaicin on the expression of CD36,and Type Ⅰ and Ⅲ collagen in spontaneously hypertensive rats

目的探讨辣椒素对自发性高血压大鼠(SHR)血液中CD36及其血管平滑肌细胞(VSMCs)中Ⅰ、Ⅲ型胶原表达的影响。方法选取30只12周龄的SHR,随机分为5组:对照组、厄贝沙坦组(1μmol/L)和高、中、低剂量辣椒素组(20、10、5μmol/L),分别测量血压,并采用流式细胞术检测血液中CD36的表达。体外构建SHR VSMCs,分别用辣椒素和厄沙贝坦直接处理细胞或特异性阻断CD36的表达后,再分别用辣椒素和厄沙贝坦处理细胞,采用qRT-PCR和Western blot检测VSMCs中Ⅰ型胶原(collagenⅠ)和Ⅲ型胶原(collagenⅢ) mRNA和蛋白的表达。结果与对照组相比,辣椒素组和厄贝沙坦组大鼠血压均有所降低,CD36、Ⅰ型和Ⅲ型胶原表达均有所下调;特异性阻断CD36表达后,辣椒素组和厄贝沙坦组Ⅰ型和Ⅲ型胶原表达均有所下调。结论辣椒素能够较好地控制SHR的血压,其降压机制一方面可能与抑制Ⅰ型、Ⅲ型胶原的合成,从而抑制血管平滑肌纤维化,逆转SHR血管平滑肌的肥厚和血管重建过程有关;另一方面可能与抑制CD36的表达,进一步抑制Ⅰ型、Ⅲ型胶原的表达有关。

Objective To investigate the effect of capsaicin on the expression of CD36 in the blood and Type Ⅰand Ⅲ collagen in vascular smooth muscle cells( VSMCs) in spontaneously hypertensive rats( SHR). Methods A total of 30 SHR( aged 12 weeks) were randomly divided into 5 groups,SHR control group,irbesartan group( 1 μmol/L) and capsaicin groups( 20,10,5 μmol/L). The blood pressure was measured and the expression of CD36 in blood was detected by flow cytometry. The spontaneously hypertensive rat vascular smooth muscle cells were constructed in vitro and were treated with capsaicin( 10 μmol/L) or irbesartan( 1 μmol/L) directly,or specifically inhibiting the expression of CD36.The changes of Type Ⅰ and Ⅲ collagen mRNA and protein expression levels were assessed by qRT-PCR and Western blot. Results Compared with the control group,the blood pressure were lowere in the capsaicin group and irbesartan group,with down-regulation of CD36,Type Ⅰ and Ⅲ collagens; which were reversed by inhibiting the expression of CD36. Conclusion Capsaicin can effectively control the blood pressure of SHR,which may be related to the inhibiting synthesis of Type Ⅰ and Ⅲ collagens. Thereby inhibiting vascular smooth muscle hypertrophy and fibrosis,reversing vascular smooth muscle hypertrophy and vascular remodeling of SHR. On the other hand,it may be associated with inhibition of CD36,and further inhibiting Type Ⅰ and Ⅲ collagen expression.