Antifertility effect of sympathomimetic drugs on male rats when applied locally to the vas deferens.
Local application of collars containing 25% methoxamine, 50% or 75% tyramine or 50% norephedrine to both vasa deferentia of rats caused a reduction in fertility but not in their ability to mate. A gradual return to fertility was seen in those animals which received the lower dose of tyramine or norephedrine, while the other treatments caused a permanent reduction in fertility. The cause of sterility was production of azoospermic ejaculates resulting from either a block in sperm transport in the vas deferens or from a deficiency in the ejaculatory mechanism. Only methoxamine caused a mechanical obstruction of the vas deferens, but it is possible that the other drugs caused a sustained spasm. An emission defect could have been due to transmitter depletion, receptor-specific desensitization or presynaptic alpha-adrenoreceptor-mediated inhibition. Spermatozoa from the cauda epididymidis were immotile following the treatments.
D000818:Animals; D002452:Cell Count; D005260:Female; D005298:Fertility / Q000187:drug effects*; D008297:Male; D008729:Methoxamine / Q000494:pharmacology*; D010665:Phenylpropanolamine / Q000494:pharmacology*; D051381:Rats; D012726:Sexual Behavior, Animal / Q000187:drug effects; D013081:Sperm Motility / Q000187:drug effects; D013091:Spermatogenesis / Q000187:drug effects; D013094:Spermatozoa / Q000166:cytology / Q000187:drug effects; D014439:Tyramine / Q000494:pharmacology*; D014649:Vas Deferens / Q000187:drug effects*
D010665:Phenylpropanolamine; D008729:Methoxamine; D014439:Tyramine