Ge. Borodic et al., BOTULINUM-B TOXIN AS AN ALTERNATIVE TO BOTULINUM-A TOXIN - A HISTOLOGIC-STUDY, Ophthalmic plastic and reconstructive surgery, 9(3), 1993, pp. 182-190
Histochemical effects of botulinum B toxin were studied on fibers from
longissimus dorsi muscle in Albino rabbits and compared to effects pr
oduced by botulinum A toxin. Acetylcholinesterase staining, muscle fib
er size analysis, and ATPase staining indicated botulinum B toxin prod
uced a denervation gradient and field similar to that produced by botu
linum A toxin. At 5 weeks postinjection with botulinum B toxin, analys
is showed muscle fiber size variability, and diffuse acetylcholinester
ase fiber staining comparable to botulinum A toxin at the injection si
te. Muscle sections taken at 4.0 cm for analysis showed statistically
significant decreased fiber size variability and contraction of acetyl
cholinesterase staining pattern for both immunotypes. In addition, the
denervation reflected by histochemical staining and fiber size analys
is appeared transient and lasted for approximately 3 months for both i
mmunotypes. These findings suggest botulinum B toxin produces pharmaco
logic effects on innervation of striated muscle similar to botulinum A
toxin. Because immunologic tolerance has been demonstrated after ther
apeutic botulinum A toxin injections, further clinical studies need to
be conducted with other immunotypes of toxin with no cross-reactivity
to type A.