眼镜蛇伤大鼠多项指标动态变化与抗蛇毒血清的时效关系

目的: 观察蛇伤后大鼠生化血气分析及病理等动态变化,探讨其与抗蛇毒血清使用时效性的关系,为优化眼镜蛇伤的临床治疗方案提供实验依据。方法: SD大鼠注入2-4 LD₅₀舟山眼镜蛇毒造模,于注毒后不同时段(20-140 min)分别进行血液生化、血气分析、肌组织病理等检测及注入抗眼镜蛇毒血清(40-120 min,血清/蛇毒:125 kU/g)对上述指标的影响。结果: 大鼠注入4 LD₅₀蛇毒20 min后二氧化碳总量(TCO₂)、剩余碱(BE)及酸碱度(pH)逐渐下降;而心酶、肝酶及胆红素明显上升,于60及120 min各出现1个峰值,与0 min相比有显著差异(P<0.05);心肌、骨骼肌于40 min时点出现广泛浊肿变性、凝固性坏死及炎症细胞浸润。注入2 LD₅₀蛇毒动物的心酶、肝酶及胆红素指标变化趋势与4 LD₅₀剂量组相似,但其峰值出现时间相对延迟且峰值较低。在心酶出现第1个峰值前施予抗血清,蛇伤大鼠的保护率可达60%以上;但第2个峰值后施予抗血清的疗效不显著。结论: 眼镜蛇伤后的心酶、肝酶等相关指标呈双峰变化规律,第2个峰值前为使用抗血清的有效时段。

Dynamic changes of biochemical indexes and time-effect relationship of antivenin in a rat model with Naja atra Cantor snake envenoming

AIM: In order to optimize the clinical treatment strategy for Cobra snakebite, the changes of biochemical indexes and blood gas, pathological alteration and time-effect relationship of antivenin application were observed in a rat model with Naja atra Cantor snake envenoming.METHODS: SD rats were injected with 2-4 LD₅₀ cobra venom, and the dynamic changes of biochemical indexes, blood gas and the pathological alteration of muscles were observed at the time points of 20 to 140 min after venom injection.The anti-Cobra venom serum (antivenom/venom=125 kU/g) were injected at the time points of 40 to 120 min after snakevenom administered and the indexes above were also measured.RESULTS: After injected with 4 LD₅₀ venom, the cardiac enzymes, liver enzymes and bilirubins in blood were increased significantly at 20th min, but the TCO₂, BE and pH were decreased.Two peaks of cardiac enzymes, liver enzymes and bilirubins were detected at 60th min and 120th min.The peak values of AST, CK and CK-MB were significantly higher than the values at 0 min (P<0.05).The markedly widespread cloudy swelling, coagulation necrosis and inflammatory cell infiltration were observed in the sections of myocardium and skeletal muscles at the time point of 40th min after injection of 4 LD₅₀ venom.The peak values of some indexes in the animals injected with 2 LD₅₀ venom were lower and delay onset than those in the animals injected with 4 LD₅₀ venom.The protective rate in the rats injected with 4 LD₅₀ venom was elevated to 60% or more when the antiserum treatment was conducted before the first peak of cardiac enzymes in blood. However, the therapeutic effect of antiserum was not effective as the rats received the treatment after the second peak of cardiac enzymes in blood.CONCLUSION: The bimodal variation of cardiac, liver enzymes and related indicators is observed in the rat model of snake envenomin.The animals can be effectively protected by the antivenom administered before observing the second peak of cardiac enzymes in blood.