Effect of TRH and dopamine on cyclic AMP levels in enriched mammotroph and thyrotroph cells.
Populations of normal anterior pituitary cells enriched in thyrotrophs or mammotrophs prepared by velocity sedimentation were used to investigate the effect of modulators of TSH and prolactin secretion on cyclic AMP accumulation. In both thyrotroph-enriched and mammotroph-enriched fractions, IBMX increased cyclic AMP accumulation. In the presence of IBMX, TRH invoked an increase in cyclic AMP suggesting that TRH modulates cyclic AMP accumulation in both of these cell types from normal pituitary glands. In the mammotroph-rich fraction, dopamine inhibited the increase in cyclic AMP induced by TRH. In contrast however, in the thyrotroph-enriched fraction dopamine lowered neither cyclic AMP concentration nor TSH secretion. Thus the inhibiting effect of dopamine on cyclic AMP appears to be specific for prolactin-secreting cells.
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism*; D004298:Dopamine / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism; D051381:Rats; D013972:Thyrotropin / Q000378:metabolism; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*
D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin; D013972:Thyrotropin; D000242:Cyclic AMP; D015056:1-Methyl-3-isobutylxanthine; D004298:Dopamine