Neurotoxic, hemorrhagic and proteolytic activities of Duvernoy's gland secretion from Venezuelan opisthoglyphous colubrid snakes in mice.

Many colubrid snakes produce toxic oral secretions. We studied venom (Duvernoy's gland secretion) collected from Venezuelan opisthoglyphous (rear-fanged) colubrid snakes. Different proteins were present in Thamnodynastes stigilis Duvernoy's gland secretion and were characterized by 20% SDS-PAGE protein electrophoresis. The venom displayed proteolytic (gelatinase) activity that was partially purified on a chromatography ionic exchange mono Q2 column. We demonstrated hemorrhagic activity of Thamnodynastes stigilis Duvernoy's gland secretion on chicken embryos and mouse skin and peritoneum. Mice inoculated with Thamnodynastes stigilis Duvernoy's gland secretion presented signs of neurotoxicity. Thamnodynastes stigilis Duvernoy's gland secretion had proteolytic, hemorrhagic, and neurotoxic activities, not previously described in this species and identifies the presence of a new venomous colubrid in Venezuela.

Inhibition of Crotalidae venom hemorrhagic activities by Didelphis marsupialis liver spheroids culture supernatants.

The main aim of this work was the development of a primary hepatocyte culture from Didelphis marsupialis, to determine the possible use of culture medium supernatants as a source of inhibitors of the Bothrops lanceolatus venom hemorrhagic activity. The cellular culture was carried out from isolated hepatocytes by the double perfusion technique, and digestion of the liver with collagenase and culturing the hepatocytes in a liquid media under continuous agitation at 37 degrees C in 5% CO2. The hemorrhagic activity inhibition assays were performed inoculating intradermically, a mixture of Bothrops lanceolatus venom plus a pool of liver spheroids culture supernatants, in mice. These liver Didelphis marsupialis spheroid cultures were adequate to obtain large supernatant volumes with inhibitors of hemorrhagic activity.