Effects of Bothrops pirajai venom on the mouse extensor digitorum longus (EDL) muscle preparation

The effects of Bothrops pirajai snake venom on the mouse extensor digitorum longus (EDL) preparation were examined using myographic, histopathological and biochemical approaches. B, pirajai venom (10, 25 or 50 mu g/ml) dose d ependently and irreversibly blocked the contractile response of indirectly stimulated EDL muscle. Histopathological analysis of EDL muscle incubated w ith venom showed dose-dependent damage with a loss of the normal tissue str ucture and the appearance of highly dark, edematous fibers together with my ofibrils in various stages of condensation. At high doses of venom (50 mu g /ml), loss of muscle cells was observed. In non-stimulated EDL, B, pirajai venom (10 and 50 mu g/ml) caused a time-dependent release of CK which was m aximal after 120 min. These results suggest that a component(s) present in the B, pirajai venom has a direct myolytic action on the skeletal muscle. ( C) 1999 Elsevier Science Ltd. All rights reserved.