Effect of piperoxane on serum prolactin: possible role of epinephrine-mediated synapses in the inhibition of prolactin secretion.
Intravenous administration of 2,5 mg/kg piperoxane produced a rapid and significant increase in serum PRL concentrations in four non-human primates. This PRL increase was maximal 15 min after piperoxane infusion and significant, when compared with baseline levels, in the +15, +30, +45, +60, and +90-min samples. The iv administration of 5 mg/kg piperoxane also produced a rapid and significant increase, whereas saline 0.5 mg/kg or 1.0 mg/kg, did not change serum PRL levels. The iv administration of 10 microgram/kg clonidine, but not saline, produced a rapid and significant reduction in serum PRL levels. PRL levels were significantly reduced +15, +30, and +60 min after the clonidine infusion. Pretreatment with a bolus of 10 microgram/kg clonidine at -15 min caused a significant attenuation of the piperoxane-induced elevation in serum PRL in two monkeys. These data support the hypothesis that alpha-adrenergic receptors are involved in the inhibition of PRL secretion. These data are compatible with noradrenergic or adrenergic mechanisms which remain to be defined.
D000818:Animals; D003000:Clonidine / Q000494:pharmacology; D004837:Epinephrine / Q000502:physiology*; D000882:Haplorhini; D008297:Male; D010880:Piperidines / Q000494:pharmacology*; D010883:Piperoxan / Q000494:pharmacology*; D011388:Prolactin / Q000097:blood*; D011941:Receptors, Adrenergic / Q000502:physiology*; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology*; D013569:Synapses / Q000502:physiology
D010880:Piperidines; D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D011388:Prolactin; D010883:Piperoxan; D003000:Clonidine; D004837:Epinephrine