Clostridium botulinum toxin A inhibits contractility in pregnant human myometrium in vitro.
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.
Burd
Irina D
ID
Thomas Jefferson University Hospital, Philadelphia, Pennsylvania 19107, USA.
Ness
Amen
A
DiMuzio
Paul
P
Ren
Gong-Yi
GY
Tulenko
Thomas N
TN
D019274:Botulinum Toxins, Type A / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D009126:Muscle Relaxation / Q000187:drug effects / Q000502:physiology; D009215:Myometrium / Q000187:drug effects / Q000502:physiology; D011247:Pregnancy; D014590:Uterine Contraction / Q000187:drug effects* / Q000502:physiology*
D019274:Botulinum Toxins, Type A