Spurious effects of commercial preparations of oxytocin on the isolated vas deferens of the rat.
1 The inhibitory effect of a commercial preparation of oxytocin (Syntocinon) was studied on the isolated vas deferens of the rat. 2 The inhibition of contractions to agonists and to field stimulation obtained were mimicked by appropriate dilutions of chlorbutol, a preservative present in Syntocinon. 3 Preservative-free synthetic oxytocin had no inhibitory effect on the tissue and slightly potentiated contractions evoked by field stimulation. 4 It is concluded that inhibitory effects of Syntocinon on the vas deferens are due to chlorbutol, not oxytocin.
D000818:Animals; D002724:Chlorobutanol / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D010121:Oxytocin / Q000494:pharmacology*; D051381:Rats; D014649:Vas Deferens / Q000187:drug effects*
D010121:Oxytocin; D002724:Chlorobutanol