[Anti-ophidic toxin action of Agkistrodon acutus serum].
The lethal effect of the venom of was protected by its serum. The serum alleviated the tissue necrosis and protected the blood system of rabbits when given a lethal dose of the snake venom. 
 In mice the LD of snake serum>2.5 g/kg. In anesthetized dogs iv the snake serum 200 mg/kg caused no influence on respiration, blood pressure, ECG，peripheral blood picture, hepatic and renal functions. No pathologic changes were found after 7 d. 
 By ammonium sulfate fractional precipitation, DEAE-Sephadex A-50 column chromatography, CM-Celluloses C-32 column chromatography and polyacrylamide gel plate electrophoresis, an an-titoxin factor was purified from the snake serum. Its isoelectric pt=4.0 and its mol wt=c 70,000. The activity of this factor against venom was increased by 10 times. 
Complement fixation tests and agar immunodiffusion tests proved that the antitoxic action of serum manifested no antigen-antibody reaction.