Furthermore, some neurotoxic sv[PLA.sub.2]s (e.g., notexin and crotoxin) cause acute skeletal muscle necrosis, adding to systemic toxic effects (i.e., rhabdomyolysis) .
Eklund, "The three-dimensional structure of notexin, a presynaptic neurotoxic phospholipase [A.sub.2] at 2.0 A resolution," FEBS Letters, vol.
Name Snake species Neurotoxin Crotoxin Crotalus durissus terrificus Ms[PLA.sub.2]-I Micrurus spixii Taipoxin Oxyuranus scutellatus Textilotoxin Pseudonaja textilis Ammodytoxin Viper a ammodytes [beta]-Bungarotoxin Bungarus multicinctus Notexin Notechis scutatus Myotoxin Myotoxin III Bothrops asper Myotoxin II B.
Most studies of skeletal muscle regeneration use acute models of injury and repair, such as sterile destruction of myofibers by either injection of toxins, such as cardiotoxin, notexin
, or barium chloride, or by performing freeze crush injuries.
Muscle injury was induced by intramuscular injection of either bupivacaine (which induces [Ca.sup.2+] release from the sarcoplasmic reticulum (SR) and simultaneously inhibits [Ca.sup.2+] reuptake into the SR, resulting in persistently increased [Ca.sup.2+]] levels and leads to myofiber death), notexin
(which involves [Ca.sup.2+] overload and activation of [Ca.sup.2+] -dependent proteases, resulting in tissue necrosis), or freezing (which causes uniform and complete necrosis of myofibers).
Three groups (RC, R20E-1 and R20E-2) received snake venom (notexin) injection into the left soleus muscle.
soleus (mg) Right Left 142.8 [+ or -] 3.64 146.0 [+ or -] 3.03 - (136-152) (137-150) 166.0 [+ or -] 6.38 * 172.0 [+ or -] 9.58 * - (156-184) (154-197) 155.0 [+ or -] 5 - 113.0 [+ or -] 6 (150-170) (100-130) 150.0 [+ or -] 4.08 - 113.0 [+ or -] 7.5 (140-160) (100-130) 178.0 [+ or -] 4.05 * - 116.0 [+ or -] 10.49 (169-188) (90-136) *, **, *** p < 0.05, 0.01, 0.001 compared to the correspondent control (0.9% NaCl and notexin + 0.9% NaCl).