The effect of neonatal treatment of mice with opioid and dopaminergic agents on the late responsiveness of vasa deferentia to opioids in vitro.
Neonatal treatment of mice with opioid and dopamine antagonists (naloxone, haloperidol and sulpiride) failed to alter the in vitro responsiveness of vasa deferentia to opioid agonists in the adulthood. Single neonatal administration of some opioid or dopaminergic agonists, viz. Met-enkephalin and piribedil, tended to enhance the sensitivity of in vitro preparations to opioid agonists, tested in adult animals. Behavioural differences and late mortality were also observed.