Comparison of the effect of scorpion venom (Buthus martensii Kashi) on the rat brain and heart mitochondria.

A partially purified fraction SVc and a purified homogeneous polypeptide SVIII were isolated from the scorpion (Buthus martensii Kashi) venom, collected in Shan Dong Province of China. SVc decreased the RCR, ADP/O and Qo2 of the rat brain mitochondria. It also decreased the cytochrome oxidase activity and increased the membrane lipid fluidity of the mitochondria. Effect of scorpion venom on the rat heart mitochondria was somewhat different from that of rat brain mitochondria. SVc also decreased RCR, ADP/O and increased the membrane lipid fluidity of heart mitochondria. However, the Qo2 and cytochrome oxidase activity were increased. SVIII has a similar effect on the rat brain and heart mitochondria, but its concentration used is only 1/10 of the effective concentration of SVc.