地尔硫唑对放射损伤心肌的保护作用

Protective effects of diltiazem on radiogenic myocardial damage

目的观察放射损伤心肌血清肌钙蛋白T(cTn-T)含量和血清肌酸激酶(CK-MB)活性及心肌超微结构钙颗粒的变化及药物地尔硫唑的影响,了解地尔硫唑对心肌的保护作用。方法30只Wistar大鼠,正常及放射损伤心肌模型的大鼠分3组,即单纯照射组、照射给药组、对照组,观察照射后3、7、14、21 d的血清cTn-T含量及CK-MB活性和34 d心肌细胞的钙颗粒分布特点与超微结构变化。结果单纯照射组与对照组比较cTn-T的含量3 d开始增高,以7 d增高最明显,14 d渐降。CK-MB活性在3、7 d增高,14、21 d均恢复正常。心肌超微结构主要改变为肌丝排列紊乱、局灶性溶解;核染色质边集;线粒体肿胀、嵴不清、嵴断裂、空泡化;钙颗粒在线粒体膜完整的明显增多,线粒体破坏的消失,可见线粒体钙化。照射给药组与对照组比较cTn-T3、7、14 d均增高;CK-MB 3、7 d增高,余无差别。心肌肌原纤维收缩态多于舒张态,肌丝排列紊乱,有轻微的局灶性溶解;核染色质轻度边集;线粒体明显肿胀,嵴断裂,空泡,线粒体外钙颗粒增多。照射给药组与单纯照射组比较cTn-T3 d增高,7、14 d漏出明显减少,CK-MB 7 d增高,cTn-T酶峰前移。心肌线粒体肿胀、空泡化以及肌溶解明显减轻,钙沉积减少。结论cTn-T含量较CK-MB活性能较好地反映心肌损伤的程度,是放射损伤心肌较理想的诊断指标。地尔硫唑对放射性心肌损伤有一定的保护作用,其机制与减轻心肌细胞内钙超载有关。

AIM To observe the changes of cTn-T, CK-MB and myocardial ultrastructure calcoglobules in radiogenic cardionecrosis and to study the effect of dihiazem on myocardium. METHODS Thirty Wistar rats were divided into three groups： radiopraxis group, diltiazem group and control group. Changes were observed in cTn-T and CK-MB at the 3rd, 7th, 14th, 21st days, and in the distribution of myocardium calcoglobules and myocardium uhrastructure at the 34th day. RESULTS Compared with those in control group, the levels of cTn-T in radiopraxis group increased in the 3rd and 7th days, peaking at the 7th day and began to decrease at 14th day. cTn-T was the highest at 7th day and began to decrease at 14th day and came to normal at 21 st day. CK-MB increased at 3rd and 7th days and came to normal at 14th and 21st days. Myxedema, degeneration and musdolysis were observed in mitochondria. Calcoglobules increased in mitochondria with intact membrane but they disappeared and some calcification could be seen in mitochondria with damaged membrane in radiopraxis group, cTn-T increased, peaking at the 3rd day and CK-MB increased at 7th day in dihiazem group. The damage of myxedema, degeneration and musdolysis in mitochondria in diltiazem group was obviously milder than that in radiopraxis group. CONCLUSION cTn-T is a highly sensitive marker in diagnosing radiogenic cardionecosis and its specificity is higher than that of CK-MB. Diltiazem has some protective effects on radiogenic cardionearsis possibly by decreasing calcium oveload in the cells of mvocardium.