Neural influence on oxytocin-induced changes of adrenomedullary catecholamines in the pigeon.
Oxytocin (0.25 IU/100 g body wt) was injected intraperitoneally only once to unilaterally splanchnic denervated pigeons. The effects were investigated after 0.5, 4, 12, 24, 72, 144 and 216 h of administration. The findings revealed that oxytocin caused the release of more norepinephrine (NE) from the denervated glands up to 24 h after treatment. In contrast, oxytocin-induced release of epinephrine (E) showed no significant difference in between the innervated and the denervated glands after 0.5 h of treatment. Strikingly, oxytocin brought about release of more E from the denervated glands after 24 h of treatment. This indicates that the first phase of NE release and the second phase of E release are neurally regulated. The findings further revealed that the resynthesis of both NE and E was faster in the innervated glands after 216 h of oxytocin treatment. This clearly points out that the splanchnic nerve accelerates resynthesis of both NE and E induced by oxytocin.
Mahata
S K
SK
Department of Pharmacology, University of Innsbruck, Austria.
Ghosh
A
A
D000313:Adrenal Medulla / Q000187:drug effects / Q000294:innervation*; D000818:Animals; D010856:Columbidae / Q000502:physiology*; D004837:Epinephrine / Q000378:metabolism*; D005260:Female; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D010121:Oxytocin / Q000494:pharmacology / Q000502:physiology*; D013153:Splanchnic Nerves / Q000502:physiology*
D010121:Oxytocin; D009638:Norepinephrine; D004837:Epinephrine