Effects of myotoxin alpha on fusion and contractile activity in myoblast-myotube cell cultures.
Cultured myoblasts and moytubes were used to study the effects of purified myotoxins from rattlesnake venoms. Standard cell culture techniques were used to establish and maintain primary cultures derived from neonatal rat tissue and two clonal cell lines, rat RMo cells and mouse C2 cells. Toxin concentrations, ranging from 0.04 to 1.0 microM, were added to the cultures at various times under distinct, well-defined conditions. Addition of myotoxin alpha to primary myoblast cultures did not appear to affect the fusion process, whereas similar experiments with two clonal cell lines produced larger myotubes when contrasted with untreated control cultures, particularly with RMo cells. The myotubes derived from primary cell cultures twitched spontaneously but the twitching ceased when the medium was replaced with a serum-free chemically defined incubation medium. Addition of myotoxin alpha to the primary myotubes incubated with serum-free defined medium caused the myotubes to twitch again. Derivatives of myotoxin alpha were prepared by reactions with tetranitromethane and with iodoacetic acid, the latter under reducing and non-reducing conditions. The resulting products, purified but not chemically characterized, were nearly devoid of activity when primary cultures were used to test activity.
Ziolkowski
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C
Department of Chemistry and Biochemistry, Arisona State University, Tempe 85287.
Murchison
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HA
Bieber
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D000818:Animals; D000831:Animals, Newborn; D002459:Cell Fusion / Q000187:drug effects; D002478:Cells, Cultured; D002999:Clone Cells; D003435:Crotalid Venoms / Q000633:toxicity*; D003470:Culture Media; D009119:Muscle Contraction / Q000187:drug effects; D009132:Muscles / Q000166:cytology / Q000187:drug effects*; D051381:Rats
D003435:Crotalid Venoms; D003470:Culture Media; C018932:myotoxin A