Effects of androctonus crassicauda and mesobuthus gibbosus scorpion venoms on the isolated rat vas deferens

Androctonus crassicauda and Mesobuthus gibbosus are two different scorpion species of Turkey with ethnomedical importances. The aim of this study is to investigate the pharmacological properties of venoms of these species on isolated rat vas deferens. Different pharmacological activities and chemical contents of these two venoms on vas deferens were observed. Epididymal portion of vas deferens always exhibited better results than prostatic part acting like a specific bioassay organ for toxins. Freeze dried venom of A. crassicauda was observed to cause a sustained contraction inhibited only by the KCl which was not observed for M. gibbosus. Both venoms were active on KCl contractions of vas deferens but in a different manner which inhibited by A. crassicauda but augmented by M. gibbosus. Only A. crassicauda had a statistically significant interaction with TEA suggesting a specific action of this venom on K+ channels. Neither of test substances were active on calcium induced contractions eliminating the role of calcium channels on the observed pharmacological actions of these venoms on vas deferens. Fractions of the venom were not active and thus were exhibited dissimilar actions when compared to the crude venoms. An interesting inhibitory interaction between Origanum onites and A. crassicauda was also observed. K+ channels and adrenergic receptors were suggested to play role on the activities of A. crassicauda and M. gibbosus. It is also shown by this study that epididymal portion of vas deferens may be used as an assay organ for venoms. Key Words: scorpion, venom, Androctonus crassicauda, Mesobuthus gibbosus, Origanum onites, vas deferens