The assessment of muscle fibre loss after the injection of the venom of Notechis scutatus (Australian tiger snake).
We have used the W.H.O. International Reference Venom from the Australian tiger snake, Notechis scutatus, to study possible methods for the assessment of local myonecrosis caused by this venom. We made subcutaneous injections of various doses (0.25-20.0 micrograms) of venom into the antero-lateral aspect of the rat hind limb. The soleus muscle was removed after 24 hr and muscle fibre loss calculated from photo-montages of histological sections. Muscle tissue which had been either frozen or wax-embedded was preferable to resin-embedded tissue for making muscle fibre counts. There was a dose-dependent relationship between muscle fibre loss and the amount of venom inoculated. One microgramme of crude venom caused the loss of 50% of muscle fibres from the soleus muscle. This dose of venom neutralized by 1.5 microliters of the W.H.O. International Standard Antivenom for Notechis scutatus. Muscle wet weight increased following the inoculation of venom, to reach a peak of 42% at a dose of 0.5 microgram. There was no correlation between fibre loss and increase in wet weight. Biochemical analysis of both the venom-damaged muscle and the plasma showed that there was a strong linear correlation (r = 0.95) between loss of muscle aspartate aminotransferase and muscle fibre loss. There was a non-linear relationship between muscle fibre loss and the increase of plasma aspartate aminotransferase (EC 2.6.1.1). There was no correlation between either the loss of muscle creatine kinase or the increase of plasma creatine kinase and muscle fibre loss. We conclude that direct measurements are required to calculate muscle fibre loss with precision, but that the loss of muscle aspartate aminotransferase AST and its release into the plasma may also be important criteria to be used when studying local necrosis.
Preston
S A
SA
Regional Neurological Centre, Newcastle General Hospital, U.K.
Davis
C E
CE
Harris
J B
JB
D000818:Animals; D000997:Antivenins; D001219:Aspartate Aminotransferases / Q000097:blood; D003402:Creatine Kinase / Q000032:analysis; D004546:Elapid Venoms / Q000633:toxicity*; D005260:Female; D009124:Muscle Proteins / Q000032:analysis; D009132:Muscles / Q000201:enzymology; D009135:Muscular Diseases / Q000139:chemically induced / Q000201:enzymology / Q000473:pathology*; D009500:Neutralization Tests; D009929:Organ Size; D051381:Rats; D011919:Rats, Inbred Strains; D013194:Staining and Labeling
D000997:Antivenins; D004546:Elapid Venoms; D009124:Muscle Proteins; D001219:Aspartate Aminotransferases; D003402:Creatine Kinase