Different time courses of recovery after poisoning with botulinum neurotoxin serotypes A and E in humans.
Botulinum toxin serotypes A and E (BoNT/A and /E) cleave the carboxy-terminus of synaptosomal associated protein-25 (SNAP-25) removing nine and 26 residues, respectively. To investigate the effect of these lesions of the same target molecule, 11 volunteers were injected with 3 IU of BoNT/A in the extensor digitorum brevis (EDB) muscle of one foot and with 3 IU of BoNT/E in the contralateral one. In addition, seven volunteers were similarly injected with mixtures of BoNT/A + BoNT/E. Compound muscular action potential (CMAP) was measured at different time intervals and the percentage variation of CMAP (%CMAP) was calculated. Unexpectedly, a much faster recovery of %CMAP after BoNT/E injections was observed. Double poisoned EBD muscles recovered similarly to BoNT/E. So, a larger deletion of the SNAP-25 molecule caused by BoNT/E leads to a faster functional recovery.
Eleopra
R
R
Divisione Neurologica, Arcispedale S. Anna, Ferrara, Italy. releopra@global.it
Tugnoli
V
V
Rossetto
O
O
De Grandis
D
D
Montecucco
C
C
D000200:Action Potentials / Q000187:drug effects; D000328:Adult; D000368:Aged; D001905:Botulinum Toxins / Q000008:administration & dosage / Q000627:therapeutic use*; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage / Q000627:therapeutic use*; D004357:Drug Synergism; D004421:Dystonia / Q000188:drug therapy*; D004558:Electric Stimulation; D005260:Female; D005528:Foot / Q000502:physiology; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000294:innervation / Q000502:physiology; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology; D013997:Time Factors
D001905:Botulinum Toxins; D019274:Botulinum Toxins, Type A; C096326:botulinum toxin type E