Dopamine regulates canine plasma beta-endorphin-immunoreactivity levels.
Intravenous administration of the dopamine antagonists domperidone and metoclopramide elevates canine plasma beta-endorphin immunoreactivity. Pretreatment with dopamine, but not dexamethasone, inhibits this effect. Sephadex G-50 chromatography shows that this response is due to beta-endorphin-like peptides, not beta-lipotropin. These findings indicate that pituitary beta-endorphin secretion is tonically inhibited by dopamine and suggest that the intermediate lobe is the source of this secretion.
D000818:Animals; D003429:Cross Reactions; D004285:Dogs; D004294:Domperidone / Q000494:pharmacology*; D004298:Dopamine / Q000502:physiology*; D004723:Endorphins / Q000097:blood*; D007700:Kinetics; D008297:Male; D008787:Metoclopramide / Q000494:pharmacology*; D011863:Radioimmunoassay; D001615:beta-Endorphin
D004723:Endorphins; D004294:Domperidone; D001615:beta-Endorphin; D008787:Metoclopramide; D004298:Dopamine