The in vitro vascular effects of two chirodropid (Chironex fleckeri and Chiropsella bronzie) venoms

Encounters with Venomous Sea-Life

“…Data presented by Winter et al in a study with rats confirmed these findings by boiling the venom for 5 min before administration (p Ͻ 0.05) (45). This intervention inhibited the hypertensive response and cardiovascular collapse.…”

“…This intervention inhibited the hypertensive response and cardiovascular collapse. Also, a pH of 3 produced an abolished cardiovascular response (p Ͻ 0.05), whereas a pH range of 5-9 had no effect on the venom interaction (45). Other studies support this, considering hot (not boiling) water immersion as an efficacious initial treatment for jellyfish stings (46,47).…”

Jellyfish Envenomation with Skin and Cardiovascular Manifestations and Treatments

“…Australian box jellyfish (C. fleckeri) stings may also be required. There are significant concerns, although, regarding the adequacy of the antivenom in reversing the neurotoxic and myotoxic effects of the venom [120]. Magnesium sulfate, which has been noted to improve the potency of the antivenom, may be added for victims of C. fleckeri with severe cardiovascular effects who did not respond to advanced life support [14,121].…”

Cardiovascular Toxicity from Marine Envenomation

“…56 Venom-induced contractile response on the aorta appear irreversible with prazosin treatment, an α1-adrenoceptor antagonist. 57 Similarly, ketanserin, a highly selective serotonin 5HT-receptor antagonist, appears ineffective in inhibiting hypertension and cardiovascular collapse following envenomation in anesthetized rats. 58 This suggests that the venom does not affect α1-helical adrenoreceptors of transmembrane proteins; this refutes a previous theory that envenomation symptoms originate from the provocation of a hyperadrenergic reaction 47 and supports an ionophoric, rather than a pore-forming mode of action.…”

“…58 This suggests that the venom does not affect α1-helical adrenoreceptors of transmembrane proteins; this refutes a previous theory that envenomation symptoms originate from the provocation of a hyperadrenergic reaction 47 and supports an ionophoric, rather than a pore-forming mode of action. 57,58 There is, however, an indication for an α-helical transmembrane-spanning region in C. fleckeri venom proteins. 59 This may potentially indicate that instead of binding to endogen receptors of transmembrane proteins of the victim, the venom uses its transmembrane-spanning region to anchor itself straight into the cell, creating pores in the process.…”