LactotrophsPituitary Gland, AnteriorProlactinSomatotrophsThyrotropin-Releasing HormoneThyrotrophsPituitary GlandHyperprolactinemiaTranscription Factor Pit-1Growth HormoneMoltingSulpirideReceptors, Dopamine D2Cadmium ChlorideDopamineExocytosisEstrous CycleCells, CulturedMembrane PotentialsCalciumRadioimmunoassayRats, Sprague-DawleyRats, WistarPotassium ChannelsEstradiol