乳酸脱氢酶(LDH)同工酶广泛分布于心肌、红细胞、肝、骨髂肌、肾、肺、脑、脾、胃、肠等各种组织细胞内及体液中,是糖代谢过程中重要的酶。它是由酶蛋白和辅酶I(NAD±)所组成。酶蛋白是由两种亚基A(H型或叫心型)及B(M型或叫肌型)所组成的四聚体,即LDH_1=B_4、LDH_2=AB_3、LDH_3=A_2B_2、LDH_4=A_3B、LDH_5=A_4 Lactate dehydrogenase (LDH) isoenzymes are widely distributed in the myocardium, erythrocytes, liver, bone iliac muscle, kidney, lung, brain, spleen, stomach, intestine and other tissue cells and body fluids, is important in the process of glucose metabolism Of the enzyme. It is composed of enzyme protein and coenzyme I (NAD ±). The enzyme protein is a tetramer composed of two subunits A (H type or cardiac type) and B (M type or muscle type), namely LDH_1 = B_4, LDH_2 = AB_3, LDH_3 = A_2B_2, LDH_4 = A_3B , LDH_5 = A_4