Effect of proteinase inhibitor on onset and development of local damage by snake envenomation

本研究的目的是评价蛋白酶抑制剂对蛇毒引起的局部和全身损伤的治疗效果。采用新开发的快速、简便的纯化方法，从大鼠血浆中纯化了一种内源性广谱蛋白酶抑制物鼠球蛋白。纯化的小鼠球蛋白对蛇科5个不同属蛇毒的出血性和水肿性形成有较强的抑制作用。结果表明，小鼠球蛋白有可能作为局部治疗蛇毒的药物。我们还评估了人工合成的金属蛋白酶抑制剂Ilomastat(GM6001)和CaEDTA对蛇毒出血和凝血活性的抑制能力。我们发现这两个化合物都能抑制蛇毒科中最强的蛇毒Echis hochureki蛇毒的出血性和凝血活性，而且几乎不受鼠球蛋白的抑制。然而，局部应用CaEDTA和/或Ilomastat不能抑制局部出血和全身凝血障碍，如果在毒液接种10min后应用这些抑制剂的话。如果在毒液中毒后1分钟应用该抑制剂，则显示出相当大的抑制局部出血和全身凝血障碍的潜力。据推测，局部接种的毒液能以惊人的速度到达全身循环。这可能是蛋白水解酶抑制剂潜力较弱的原因。全身应用抑制剂以及局部应用对循环毒素可能是有效的。

The aim of the present investigation is to estimate the efficacy, of proteinase inhibitors on treatment of local and systemic damage provoked by snake venom. An intrinsic broad-spectrum proteinase inhibitor, murinoglobulin, was purified from rat plasma employing newly developed rapid and easy purification method. The purified murinoglobulin showed strong inhibitory activity against hemorrhagic and edema forming activities of snake venoms from 5 different genera in Viperidae family. The results showed the possible potential of murinoglobulin as an agent for local treatment of snake envenomation. We also estimated the inhibitory capacity of synthetic metalloproteinase inhibitor, Ilomastat (GM6001) and CaEDTA against snake venom hemorrhagic and coagulation activities. We found that both of compounds inhibited hemorrhagic and coagulation activities of Echis shochureki venom which is the most powerful venom among Viperidae family and hardly inhibited by murinoglobulin. However, local application of CaEDTA and/or Ilomastat failed to inhibit local hemorrhage and systemic coagulopathy if applied those inhibitors 10 min after venom inoculation. In case, the inhibitor was applied one minutes after the envenomation, it showed considerable potential to suppress local hemorrhage and systemic coagulopathy. It is assumed that locally inoculated venom could reach systemic circulation surprisingly fast. It might be the reason for the rather weak potential of proteinase inhibitors. Systemic application of inhibitors as well as local application might be effective on circulating toxins.