Haemodynamic effects of the crude venom from nematocysts of the box-jellyfish Chiropsalmus quadrigatus (Habu-kurage) in anaesthetized rabbits.
Haemodynamic effects of saline-extracted venom from nematocysts isolated from tentacles of the box-jellyfish Chiropsalmus quadrigatus (Habu-kurage) were investigated. In anaesthetized rabbits, i.v. injections of the venom produced hypotension following a transient hypertension. Mean femoral arterial blood flow markedly decreased immediately after the injection and femoral vascular resistance increased. Left ventricular dP/dt remarkably decreased after a transient and small increase, and heart rate decreased. Left ventricular end-diastolic pressure markedly elevated. All of the above changes by 0.2-5 microg/kg of the venom expressed as the amount of protein were seen dose-dependently and occurred without tachyphylaxis. In five of seven animals received an injection of the venom at 10 microg/kg, irreversible cardiac arrest occurred. Changes produced by 1 or 2 microg/kg of the venom were significantly attenuated either by heating the venom at 40 degrees C for 10min or by pretreatment with diltiazem. These results indicate that the venom from Habu-kurage has both vasoconstrictor and cardiodepressive effects, and suggest that these thermolabile actions may be due partly to activation of voltage-dependent calcium channels and probably subsequent calcium-overload.
Koyama
Tomoyuki
T
Department of Pharmacology, School of Medicine, Faculty of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-cho, Okinawa 903-0215, Japan.
Noguchi
Katsuhiko
K
Matsuzaki
Toshihiro
T
Sakanashi
Mayuko
M
Nakasone
Junko
J
Miyagi
Kanako
K
Sakanashi
Makiko
M
Sakanashi
Matao
M
D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D003064:Cnidarian Venoms / Q000008:administration & dosage / Q000633:toxicity*; D037462:Cubozoa; D004110:Diltiazem; D004305:Dose-Response Relationship, Drug; D005263:Femoral Artery / Q000502:physiology; D006439:Hemodynamics / Q000187:drug effects*; D007275:Injections, Intravenous; D008297:Male; D011817:Rabbits
C465975:Chiropsalmus quadrigatus toxin-A; D003064:Cnidarian Venoms; D004110:Diltiazem