支链氨基酸对大鼠心肌缺血损伤的防护作用

PROTECTION OF BRANCHED CHAIN AMINO ACIDS ON ISCHEMIC MYOCARDIAL INJURY IN RAT

目的：观察支链氨基酸（ＢＣＡＡ）对大鼠心肌缺血损伤的预防作用。方法：选用Ｗｉｓｔａｒ大鼠３０只，随机分成三个组，每组１０只。Ａ组：正常对照组；Ｂ组：异丙肾上腺素（ＩＳＯ）对照组；Ｃ组：ＩＳＯ＋ＢＣＡＡ组，其中Ｂ、Ｃ组用ＩＳＯ造成大鼠心肌缺血性损伤。用酶试剂盒和原子吸收法测定了血清、心肌中ＬＤＨ、ＧＯＴ、α－ＨＢＤＨ、ＣＫ、ＰＫ的酶活力及心肌中Ｋ＋、Ｍｇ２＋、Ｃａ２＋离子的含量。结果：Ｂ组大鼠血清和心肌中ＬＤＨ、ＧＯＴ、α－ＨＢＤＨ、ＣＫ、ＰＫ的酶活力均明显升高，心肌中Ｃａ２＋的含量也显著升高，而Ｍｇ２＋的含量明显降低，Ｋ＋含量也有下降的趋势，但变化不显著。Ｃ组大鼠血清中ＬＤＨ、α－ＨＢＤＨ、ＣＫ、ＰＫ的酶活力明显低于Ｂ组，而且ＣＫ的活力接近正常水平；心肌中ＬＤＨ、ＧＯＴ、α－ＨＢＤＨ、ＣＫ的活力均低于Ｂ组并达到正常水平。补充ＢＣＡＡ后能有效地拮抗心肌细胞内钙的增加，使心肌内Ｃａ２＋含量明显低于Ｂ组，与正常对照组无显著差异，但ＢＣＡＡ不能升高受损心肌中Ｍｇ２＋的含量。

In order to study the preventive effects of BCAA on ischemic myocardium in rat,30 Wistar rats were randomly divided into 3 groups and 10 rats in each group.Group A:control group;group B:ISO group;group C:ISO+BCAA group.Isoproternol (ISO) induced acute ischemic myocardial injury in group B and group C.The activity of LDH,GOT,α HBDH,CK,PK in serum and myocardium and the contents of K +,Mg 2+ ,Ca 2+ in myocardium were measured by using enzymic reagent boxes and atomic absorption spectrum respectively.The results showed that the activity of LDH,GOT,α-HBDH,CK,PK in serum and in myocardium was significantly increased in group B.The content of Ca 2+ in myocardium was also significantly increased in group B while the content of Mg 2+ in myocardium was significantly decreased.The content of K + in myocardium was insignificantly decreased.In group C,the activity of LDH,α HBDH,PK,CK in serum was significantly lower than in group B and the activity of LDH,GOT,α HBDH,PK,CK in myocardium was also significantly lower than in group B which showed no significant difference with the normal group.Supplementation of BCAA could effectively antagonize the increase of calcium in myocardium,but could not increase the level of Mg 2+ .It was concluded that supplementation of BCAA could produce some protective effects on ischemic myocardium.