title: Effects of Botox and Neuronox on muscle force generation in mice.
abstract: The current study determined the dose-response relationship for inhibition of muscle force of two commercially available botulinum neurotoxin type-A (BoNTA) preparations (Botox and Neuronox) in a murine model and characterized the time course of recovery from the toxin-induced muscle paralysis. The effect of freezing reconstituted toxin on toxin potency was also determined. The gastrocnemius muscles in male CD-1 mice were injected with either saline or BoNTA (0.3-3.0 U/kg), and muscle force generation was examined following stimulation of the tibial nerve (single twitch and 15-200 Hz tetany). Botox and Neuronox produced nearly equivalent decrements in muscle force (30%-90%) at 4 days after toxin injection. At 28 days after injection (1 U/kg), muscle force had recovered from the effects of both toxin preparations. Maintaining reconstituted toxin at -80 degrees C for up to 5 months did not result in significant loss of toxin activity. The results of this study suggest that Botox and Neuronox produce equivalent responses in a murine model, and, in contrast to other models, muscle recovery is rapid with doses of toxin that produce less than maximal decrements in muscle force.
authors.affiliation: Department of Orthopaedic Surgery, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157, USA.
authors.forename: Austin V
authors.initials: AV
authors.lastname: Stone
authors.forename: Jianjun
authors.initials: J
authors.lastname: Ma
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Whitlock
authors.forename: L Andrew
authors.initials: LA
authors.lastname: Koman
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Smith
authors.forename: Beth P
authors.initials: BP
authors.lastname: Smith
authors.forename: Michael F
authors.initials: MF
authors.lastname: Callahan
mesh_terms: D000818:Animals; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005615:Freezing; D007273:Injections, Intramuscular; D008297:Male; D051379:Mice; D046210:Microfluidic Analytical Techniques; D053580:Muscle Strength / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects*; D010243:Paralysis / Q000139:chemically induced*; D013997:Time Factors
chemical_list: D019274:Botulinum Toxins, Type A