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In vitro studies on the regulation of prolactin secretion in the bullfrog pituitary gland

1982; Elsevier BV; Volume: 46; Issue: 4 Linguagem: Inglês

10.1016/0016-6480(82)90102-2

1095-6840

Tatsunori Seki, Sakaé Kikiyama,

Receptor Mechanisms and Signaling

The effects of dopamine, a dopamine agonist, dopamine antagonists, and serotonin on the incorporation of [3H]leucine into bullfrog pituitary prolactin (PRL) in vitro were studied. CB154, a dopamine agonist, as well as dopamine, inhibited the release of the newly synthesized PRL from the pituitary gland. Incomplete restoration of the dopamine-inhibited PRL release was observed when pimozide or haloperidol, a dopamine antagonist, was added to the incubation medium. Relatively higher doses of pimozide or haloperidol were effective by themselves in enhancing the synthesis and release of PRL in a dose-dependent manner. On the other hand, a lower dose of pimozide or haloperidol acted rather suppressively on the release of PRL. Serotonin was found to be effective in stimulating the synthesis and release of PRL by acting directly on the pituitary gland. The possible regulatory mechanism of PRL secretion in bullfrogs by dopamine and serotonin is discussed.