Effect of thyrotropin-releasing hormone and dopamine on the in vitro secretion of prolactin by the bullfrog pituitary gland.
Pituitary glands of bullfrogs (Rana catesbeiana) were incubated in medium containing thyrotropin-releasing hormone (TRH) and/or dopamine in order to see their effects on the release and synthesis of prolactin, which was measured by a homologous radioimmunoassay. Prolactin synthesis was measured by monitoring the incorporation of [3H]leucine into prolactin. TRH (0.1-10 ng/ml) stimulated the release of immunoassayable prolactin and newly synthesized [3H]prolactin into the medium in a dose-dependent manner; however, it was ineffective in increasing total prolactin (medium plus pituitary) and the incorporation of [3H]leucine into the total prolactin during the experimental period (20 hr). The TRH-induced elevation of prolactin release was suppressed by the addition of dopamine (5 X 10(-7) M) to the medium.
Seki
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Kikuyama
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D000818:Animals; D004298:Dopamine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007930:Leucine / Q000378:metabolism; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D011388:Prolactin / Q000096:biosynthesis / Q000378:metabolism*; D011892:Rana catesbeiana; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*
D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin; D007930:Leucine; D004298:Dopamine