绿茶多酚改善环孢素A抑制血管舒张的作用

Objective To observe the alleviation effect of green tea polyphenols (GTP) on cyclosporine A (CsA)-induced inhibition of vasodilation, and to study the underlying mechanism. Methods Thirty SD rats were randomly divided into three groups: CsA group, control group and CsA + GTP group. Five weeks after the treatment, the body weight, kidney function (BUN, Cr) of the rats were measured. Then thoracic aorta rings were mounted on a bath system, and the Ach-induced vasodilation, the effect of L-NAME and indomethacin pretreatment on the vasodilation and the denuded vasodilation were evaluated. The contents of nitric oxide (NO) in the vascular tissues were measured. Results Five weeks later, the body weight of the rats in CsA group (253.2 ±8.1) g was lighter than that in control group (292.1 ±9.5) g (P < 0.05);the body weight in CsA + GTP group (287.9 ± 9.7) g was heavier than that in CsA group ( P < 0.05);The levels of BUN and Cr in CsA group were higher than in control group (P <0.05);The levels of BUN and Cr in CsA + GTP group were lower than in CsA group (P <0.05). The maximal response for Achinduced vasodilation in CsA group was (42.5 ±4.3)% , significantly lower than (81.2 ±7. 6)% in control group and (70.1 ± 6.5) % in CsA + GTP group (both/P < 0.05). After pretreatment with L-NAME, the vasodilation in CsA group and CsA + GTP group was (40.3 ±3.7)% and (45.8 ±4.2)% respectively, lower than in control group (79. 4 ± 6. 8)% ;After pretreatment with indomethacin, the vasodilation in control group and CsA + GTP group was higher than in CsA group (both P < 0.05). The vasodilation in the denuded groups was inhibited, but there was no significant difference between groups (P>0.05). In CsA group, the content of NO in vascular tissues was lower than that in control group and CsA + GTP group (both P < 0.05). Conclusion CsA might decrease the NO content in vascular tissues and induce abnormal endothelium-dependent vasodilation which is mediated by NO. The administration of GTP could increase the NO content and alleviate the CsA-induced inhibition of the endothelium-dependent vasodilation.

Alleviation effect of green tea polyphenols on cyclosporine A-induced inhibition of vasodilation