The Cardiovascular Pharmacology of Snake Venoms From Papua New Guinea and Australia

Papua New Guinean snakes produce a wide range of toxins that affect different organ systems. Apart from the dominant clinical effects caused by neurotoxins and procoagulants, the venoms of some PNG snakes are also known to affect the cardiovascular system. Patients bitten by Papuan taipans (Oxyuranus scutellatus) may experience syncope or loss of consciousness very soon after being bitten, and those who survive and present at hospital show cardiac rhythm disturbances that are thought to be due to direct cardiotoxic effects. In addition, other threatening cardiovascular events such as extreme lowering or raising of heart rate or blood pressure have been observed after envenoming by some PNG snake species, underlining the cardiotoxic potential of PNG snake venoms. We are especially interested in the cardiovascular pharmacology of Papuan taipan and PNG small-eyed snake (Micropechis ikaheka) venoms, as well as Australian brown snake (Pseudonaja spp.) and taipan (Oxyuranus spp.) venom. In close collaboration with the Cardiovascular Therapeutics Unit, our research aims to elucidate the mechanism of cardiotoxicity using isolated cardiovascular tissues in vitro and in integrated preparations in vivo. The effectiveness of antivenoms raised against these species in Australia and Costa Rica will be compared against cardiovascular responses to particular snake venoms. In doing so, we are seeking further insights into the action of these venoms, providing avenues for novel drug discovery, as well as improvements in the treatment of envenomation. 

Figure 1 : University of PNG Honours students Ben Bande (left) and Julious Jacobs (right) preparing venom gland cDNA extracts for PCR in the collaboratively funded Charles Campbell Toxinology Laboratory (CCTC) at the University of PNG. Training future PNG scientists in basic laboratory techniques is an important way in which AVRU contributes to the community through its activities in Papua New Guinea. INSET: Papuan taipan (Oxyuranus scutellatus) hatching in CCTC's Serpentarium at UPNG; more than 50 snakes are kept there for research.