THALASSOPHRYNE NATTERERI FISH VENOM - BIOLOGICAL AND BIOCHEMICAL-CHARACTERIZATION AND SERUM NEUTRALIZATION OF ITS TOXIC ACTIVITIES

Envenomation by Thalassophryne nattereri fishes are an important medic al problem in northeast of Brazil, causing in human victims considerab le pain and edema followed by necrosis. Venom obtained from fresh capt ured specimens of this fish was tested in vitro or in animal models fo r a better characterization of its toxic activities. Intradermal injec tion of the venom in the foot pad of mice induced local edema and hemo rrhage followed a few hours later by necrosis. Subcutaneous injection of the venom induced systemic effects consisting in jerking motions, p aralysis of hind limbs, erection of hair, rotational movements and vio lent convulsions followed by death. Dead animals showed hyperemia of t he small intestine and lungs. The venom showed distinct edematous, nec rotizing and hemolytic activities, a low level of hemorrhagic, myotoxi c and proteolytic activities and no detectable phospholipase A(2) acti vity. SDS-PAGE analysis of the crude venom showed at least 17 componen ts with the major band located around M-w= 19,000. Almost all proteins stained by amido black were also revealed by Western blotting with an tibodies to T. nattereri venom. Fractionation of the venom by either g el filtration or cation exchange chromatography resulted in a few dist inct peaks but in both situations the biological activities were locat ed in only one of the peaks which corresponded to basic proteins with approximately M-w =47,000. Heating of the venom at 56 degrees C for 60 min completely destroyed its biological activities. All venom toxic a ctivities except edema were completely neutralized after in vitro incu bation with anti-T. nattereri serum. (C) 1998 Elsevier Science Ltd. Al l rights reserved.