Effective Pattern Of Botulinum Toxin Type A On Twitching And Tetanus Contraction Of Skeletal Muscles Triggered By Electric Stimulating Nerves In Toad

Objective: The effect of botulinum toxin type A (BTX-A), an inhibitor for blocking acetylcholine (ACh) release from cholinergic nerves in skeletal muscle through cleaving the synaptosomal associated protein (SNAP)-25 and leading to the inability of synaptic vesicles containing ACh to undergo exocytosis, on twitching and tetanus contraction of gastrocnemius triggered by electric stimulating sciatic nerve was investigated in toad. The efficiency curves of contractile tension of skeletal muscles after various dosages BTX-A injection at different acting time were further analyzed. The aim of the present study is to understand the effective pattern of BTX-A on skeletal muscle, in order to find some medicaments to prevent new nerve from growth and from recovery of inefficient pre-synaptic membrane caused by BTX-A.Methods: Toads (80-90 g) were randomly divided into two groups: (1) Suxamethonium chloride, nicotinic receptor antagonist to block ACh acting post-synaptic membrane, treated group which was subdivide into control group (n=44) injected ringer's solution (RS, 0.2 ml) into left gastrocnemius and SCh administrated group (n=44) injected SCh (0.04 mg) into right gastrocnemius. (2) BTX-A treated group, which was subdivide into control group (n=134) injected ringer's solution (0.2 ml) into left gastrocnemius and BTX-A administrated...