Clostridium botulinum toxin a inhibits contractility in pregnant human myometrium in vitro

Irina D. Burd, Amen Ness, Paul Dimuzio, Gong Yi Ren, Thomas N. Tulenko

Research output: Contribution to journalArticlepeer-review


Studies were undertaken to evaluate the effect of Botulinum neurotoxin type-A (BoNTA) preparation on oxytocin-induced contractions of pregnant human myometrium in vitro. Human myometrial tissue was exposed to increasing concentrations (1-50 000 U/mL) of BoNT/A. Isometric contractions were measured using a force displacement transducer. The cumulative effect of BoNT/A on myometrial activity (time to half relaxation [TTR50], frequency, and amplitude) was evaluated. The frequency of myometrial contractions was depressed by 40% from baseline (P <.05) and relaxation time was increased by 30% (P <.05) from baseline within a narrow range of concentrations. There was no significant difference in amplitude. The observed effects were rapidly reversed after complete wash out of the tissue. BoNT/A or its analogues with more specific tissue affinity may be of value as future agents for prevention of unwanted uterine contractile activity associated with preterm labor and fetal surgery.

Original languageEnglish (US)
Pages (from-to)1001-1004
Number of pages4
JournalReproductive Sciences
Issue number10
StatePublished - Oct 2009
Externally publishedYes


  • Botox
  • Clostridium botulinum toxin A
  • Preterm labor
  • Tocolysis
  • Uterine smooth muscle.

ASJC Scopus subject areas

  • Obstetrics and Gynecology


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