Proteases from Lonomia obliqua venomous secretions: comparison of procoagulant, fibrin(ogen)olytic and amidolytic activities.

The hemorrhagic syndrome caused by Lonomia obliqua caterpillars is an increasing problem in Southern Brazil. The clinical profile is characterized by both hemorrhagic and pro-coagulant symptoms, constituting a paradoxical action of the venom. The effects upon blood coagulation and fibrin(ogen)olysis have been shown to result from the combined action of several active principles found mostly in the bristle extract. The present study reports quali-quantitative differences among L. obliqua secretions: Cryosecretion, hemolymph, bristle extract and tegument extract. Cryosecretion and hemolymph displayed strong amidolytic activity upon several substrates, presented moderated procoagulant activity and high fibrinogen degrading ability. Bristle and tegument extracts presented low amidolytic activity, but bristle extract showed the most potent procoagulant activity and both extracts presented low fibrinogen degrading ability. The differential involvement of these secretions during the accidents with L. obliqua can elucidate the different symptoms presented after envenomation.