Comparison of the Action of Types A and F Botulinum Toxin at the Rat Neuromuscular Junction
Abstract
Blockade of neuromuscular transmission was produced in the lower hind limb of the rat by local injection of either type A or type F botulinum toxin (BoTx). At 1, 3, 7 and 10 days after injection, the extensor digitorum longus (edl) nerve-muscle preparation was excised and analyzed for alterations in muscle mechanical properties or spontaneous and nerve stimulus-evoked quantal transmitter release. Muscles receiving type A toxin were paralyzed up to and including 7 days after injection. Muscles treated with type F toxin, although completely paralyzed at 1 and 3 days, twitched in response to nerve stimulation by 7 days after injection. Both toxins induced a marked decrease in the frequency of miniature endplate potentials, but type A did so to a great extent. At 1 and 3 days after toxin injection nerve impulse evoked transmitter release was reduced for both type A- and type F-treated muscles. However, 3,4- diaminopyridine (3,4-DAP), an agent which increases nerve-evoked transmitter release by increasing Ca2+ influx, was more effective in reversing the paralysis in type A- than in type F-treated muscles.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 22, 1984
- Accession Number
- ADA146697
Entities
People
- J. A. Kauffman
- J. F. Way Jr.
- L. C. Sellin
- L. S. Siegel
Organizations
- United States Army Medical Research Institute of Infectious Diseases