Author/Editor     Bunc, Matjaž; Drevenšek, Gorazd; Budihna, Metka; Šuput, Dušan
Title     Effects of equinatoxin II from Actinia equina (L.) on isolated rat heart: the role of direct cardiotoxic effects in equinatoxin II lethality
Type     članek
Source     Toxicon
Vol. and No.     Letnik 37
Publication year     1999
Volume     str. 109-23
Language     eng
Abstract     Equinatoxin II is a lethal basic protein isolated from the sea anemone Actinia equina (L.) with LD50 in mice 35 micro/kg. The putative cause of death is cardiorespiratory arrest, but the mechanism of cardiotoxicity is poorly understood. It is not clear whether the toxin injected intravenously into an experimental animal reaches the heart in a concentration sufficient to cause direct effects on the heart. Therefore experiments were performed on rats and on isolated rat hearts in order to investigate the possible direct cardiotoxie effects of the toxin. For this reason the hearts were perfused with different concentrations of the toxin and with the effluent the lungs collected during perfusion of the lungs with equinatoxin II. The results revealed the clear dose-dependet, direct cardiotoxic effects of the toxin and of the effluent from the lungs on Langendorff's heart preparations. The threshold concentration of equinatoxin II causing a drop in the perfusion rate, deerased left ventricular pressure arrhythimia and increased LDH release, was found to be around 0.1 to 1nM equinatoxin II the left ventricular pressure dropped to 14+- 11% of the control, and the coronary flow to 9+- 3%. These effects were followed by arrhythmia and cardiac arrest. The concentration of equinatoxin recovered from the lungs after the perfusion with 100 nM equinatoxin II ranged between 0.8 and 5nM. The results indicate that direct cardiotoxie effectss of equinatoxin II play an important role in the lethal effects of the toxin.
Descriptors     HEART
CNIDARIAN VENOMS
RATS, WISTAR
SEA ANEMONES
BLOOD PRESSURE
ELECTROCARDIOGRAPHY
HEMOLYSIS
HEART RATE