EFFECT OF MAMMALIAN THYROTROPIN RELEASING HORMONE ON PROLACTIN SECRETION BY BULLFROG ADENOHYPOPHYSES INVITRO

The effects of the mammalian thyrotropin-releasing hormone (TRH) on the secretion of prolactin [PRL] secretion were investigated in short-term incubation and 24 h organ culture experiments. PRL in the medium or in the incubated tissue was measured by either polyacrylamide disc gel electrophoresis and densitometry or by a homologous radioimmunoassay. The TRH was consistently effective in promoting PRL release in vitro in concentrations of 10 ng/ml to 10 .mu.g/ml. The tripeptide also caused an increase in the tissue PRL content over a wide range of concentrations. TRH may function as a PRL-releasing factor in the bullfrog.