Isolation and pharmacological properties of phospholipases A2 from Vipera russelli (Russell's viper) snake venom.

By means of Sephadex G-75 column chromatography, Vipera russelli venom was separated into five fractions. The phospholipase A2 (PLA2) activity was concentrated in Frs. II and III. These two PLA2 fractions were rechromatographed on CM-Sephadex C-50. Several subfractions of Fr. II and Fr. III contained PLA2 activities. Frs. III-3, III-6 and III-10 showed single bands in SDS-polyacrylamide gel electrophoresis with molecular weights estimated to be 15,054, 15,167 and 15,029, and isoelectric points of 4.15, 8.80 and greater than 10, respectively. Fr. III-3 had the most potent neuromuscular blocking action on the chick biventer cervicis nerve-muscle preparation, causing a complete neuromuscular blockade at 3 micrograms/ml. The response of the muscle to ACh, tested after complete blockade, was not altered. Most PLA2 subfractions had hypotensive actions in rats at 0.1 mg/kg. In the guinea-pig lung, Frs. II-5, II-7, III-3, III-6 and III-10 increased the perfusion pressure, which may account for part of their hypotensive actions.