Abstract
Pathological changes of anterior tibial muscles after injection of Habu toxin and the effect of antitoxin were studied in 27 rabbits. 6mg of Habu toxin diluted in 0.05ml of saline was injected into the right anterior tibial muscle. 0.05ml of saline was also injected to the left anterior tibial muscle and served as a control. Rats were divided into the following five groups; four groups received intravenous antitoxin at zero, one, three and six hours after intramuscular Habu toxin injection and one group did not receive antitoxin at all. The % wet weight of the right anterior tibial muscle compared with the left side was 67±19% in the group that received antitoxin immediately after injection of Habu toxin, 48±13% in the group that received antitoxin at one hour, 44±9% at three hours, 25±10% at six hours and 27±4% in the group without antitoxin. Histological examination revealed slight degeneration of muscle in the group that received antitoxin immediately, moderate degeneration of muscle was seen in the group that received the injection after 3 hours, whereas, almost all muscle fibers degenerated and were replaced by fibrosis in the group that received antitoxin after six hours. Intravenous antitoxin will effectively reduce the degree of muscle degeneration but may not be effective after 6 hours of injection of Habu toxin.
