膳食硒、维生素E对克山病大鼠心肌胶原代谢及金属基质蛋白酶Ⅱ活力的影响

目的探讨低Se、低VE是否在心肌损伤后的修复过程中持续发挥作用,观察适时适量补充Se和VE,是否可减轻和逆转过度的心肌胶原蓄积。方法 Wistar大鼠30只,随机取6只大鼠做正常对照组,采用混合饲料喂养。其他大鼠均采用低Se、低VE半合成饲料喂养。81 d后,除正常对照组外,其余大鼠注射异丙基肾上腺素制备偏食大鼠心肌纤维化模型。制模成功大鼠分为4组,半合成饲料组(EG)继续采用半合成饲料喂养。其余各组膳食中施加干预如下:半合成饲料加Se组、半合成饲料加VE组、半合成饲料加硒加VE组。喂养21d后,乙醚麻醉,眼球采血,取大鼠心脏,观察大鼠氧化应激指标和心肌胶原代谢情况。结果偏食心肌纤维化模型组大鼠血清中谷胱甘肽过氧化物酶活力下降,脂质过氧化物含量升高。心肌胶原蓄积,并伴有金属基质蛋白酶-2、金属基质蛋白酶抑制剂-2表达上调、两者比值降低。膳食中补充Se、联合补充Se和VE均可一定程度的缓解这些改变。结论低Se、低VE在心肌损伤后的修复过程中持续发挥作用,适时适量的补充Se和VE有利于减轻和逆转过度的心肌胶原蓄积。

EFFECTS OF SELENIUM AND VITAMIN E DIET ON COLLAGEN METABOLISM IN RAT WITH MYOCARDIAL FIBROSIS

To explore whether low selenium and vitamin E play a continuing role in the repair process after myocardial injury and investigate whether timely and adequate complementary selenium and VE is able to reverse the excessive accumulation of myocardial collagen.Method Thirty Wistar rats were selected and 6 rats were taken to the control group and fed with mixed grain.Other rats were given low-Se,low VE semi-synthetic diet feed for 81 d.Then,the rats were injected with isoproterenol to make myocardial fibrosis model except the control group.The successful model rats were divided into 4 groups:semi-synthetic diet group(EG) fed with semi-synthetic diet continuously;semi-synthetic diet plus Se group,semi-synthetic diet plus VE group,semi-synthetic diet plus selenium and VE group.21 d later,all rats were sacrificed,and the oxidative stress indicators in serum and myocardial collagen metabolism were detected.Results In the model group,the serum glutathione peroxidase activity was decreased,the level of serum lipid peroxidation increased,myocardial collagen accumulated,the expression level of matrix metalloproteinases-2(MMP-2) and tissue inhibitors of MMP-2(TIMP-2) up regulated,and the ratio of expression level between the MMP-2 and TIMP-2 decreased.Supplementation of Se and VE to the diet can alleviate these changes.Conclusion Low selenium and vitamin E play a continuous role in the repair process after myocardial injury.Timely and adequate supplementation of selenium and VE is able to reverse the excessive accumulation of myocardial collagen.