Cardiovascular effects and lethality of venom from nematocysts of the box-jellyfish Chiropsalmus quadrigatus (Habu-kurage) in anaesthetized rats

摘要

Haemodynamic effects of saline-extracted venom from nematocysts isolated from Chiropsalmus quadrigatus (Habu-kurage) were studied in anaesthetized rats. Intravenous administration of venom (0.2-5 Vg protein/kg) produced immediately dose-dependent hypertension and bradycardia. Femoral blood flow transiently increased but calculated femoral vascular conductance decreased. Changes caused by I mu g/kg of venom were reproducible, and were not affected by prazosin, atropine or BQ123 (ETA receptor antagonist) but were significantly attenuated by nicardipine. At doses over 2 mu g/kg, hypotension and a decrease in pulse pressure were observed subsequent to transient hypertension. In 5 of 8 rats received 5 mu g/kg venom and 6 of 6 rats at 10 mu g/kg, death due to irreversible cardiac arrest occurred within 30 min after intravenous injection. However, during nicardipine infusion, venom (10 mu g/kg) exerted only modest effects and the rats survived. Heating venom (50 degrees C for 10 min) before injection practically abolished the haemodynamic effects of 10 mu g/kg venom, indicating its thermolability. Data show that C. quadrigatus venom has both vasoconstrictor and cardiodepressive effects in rats, and suggest that a calcium channel blocker can protect against the cardiovascular and lethal effects of the venom. (c) 2005 Elsevier Ltd. All rights reserved.