眼镜蛇神经毒素低分子量水解物的镇痛研究

The Analgesic Action of Low Molecular Catabolite from the α Cobrotoxin of Chinese Cobra Venom

眼镜蛇神经毒素（αｃｏｂｒｏｔｏｘｉｎ 或 Ｎ Ｔ） 经胃液水解后超滤得分子量＜ ３ ０００ ｕ 低分子量αｃｏｂｒｏｔｏｘｉｎ 胃液水解物 （αｃｏｂｒｏｔｏｘｉｎ ｆｒａｇｍ ｅｎｔ， Ｎ Ｔ Ｆ）。该低分子量产物在小鼠热板及大鼠电尾嘶叫测痛实验， 都显示出明显的镇痛作用，并有剂量—效应关系。 Ｎ Ｔ Ｆ毒性比 Ｎ Ｔ 明显降低， Ｎ Ｔ Ｆ的镇痛显效时间比 Ｎ Ｔ 提前， 维持时间长，不产生耐受现象。

The α cobrotoxin, NT, is the neurotoxin from the venom of Chinese cobra, Naja naja atra.The α cobrotoxin fragment, NTF, is the catabolite by the human gastric juice in vitro and is ultrafiltrated to obtain the fragment of low molecular weight less than 3000 u. The analgesic action of NTF was tested by the hot plate method for mice and the electric tail stimulation method for rats.Both analgesic methods demonstrated analgesic action and had a dose effect relationship. The analgesic start time of NTF was quicker than the NT and the analgesic duration was longer than the NT.The toxicity of NTF was lower than that of NT by means of LD 50 for mice. It was no drug tolerance in successive doses daily for NTF in rat.