The synthesis and release of hormones from human adenohypophyses in vitro

Typescript.Thesis (Ph. D.)--University of Hawaii, 1971.Bibliography: leaves 216-232.xx, 232 l illus., tablesIsolation of human prolactin (HP) from fetal and tumor culture medium which was distinct from human growth hormone was achieved by column chromatography. These preparations were studied by chromatoelectrophoresis, radioimmunoassay and polyacrylamide gel electrophoresis (PAGE). The isolated fractions were then compared with two preparations of Pasteels' human prolactin which were further purified by Dr. Lyons (Lyons' PHP and Lyons' cPHP) and the other HP preparations by radioimmunoassay, PAGE and NH2-terminal studies. The HP preparation from fetal culture medium was found to be the most highly purified and immunopotent preparation and most suitable for a radioimmunoassay for human prolactin in plasma. Forty-four human fetal pituitaries and two human pituitary adenomas were studied in organ culture for up to 11 months. Radioimmunoassays for human growth hormone (HGH), human prolactin (HP), luteinizing hormone (LH), follicle-stimulating hormone (FSH), thyroid-stimulating hormone (TSH), adrenocorticotropin hormone (ACTH) and melanocyte-stimulating hormone (MSH) were performed on the culture medium from the pituitary organ cultures. The hormones released into the medium were studied throughout the time in culture and related to the age of the fetal pituitary when first cultured and to its sex. The release of HGH, FSH, LH and ACTH gradually decreased during the first 20 days in vitro to basal or undetectable levels. The release of HP and MSH initially decreased and then increased with the time in culture to a sustained elevated level of release. The total release of each hormone was studied and could be related to various events in fetal development. Pituitaries from six fetuses which had an abnormal total release of pituitary hormones could be related to a fetal abnormality in three cases. Studies of pituitary anlage tissue from embryos as early as five weeks of gestation released hormones in vitro. That these hormones were synthesized in vitro was shown by incorporation of Cl4-leucine into these hormones as determined by PAGE and specific antibody precipitation of each hormone prior to PAGE. Some factors controlling the release of hormones in vitro were studied by the use of modified media. An increased release was obtained with an increased Ca++ and K+ in the medium whereas EDTA caused a decrease in FSH and LH and an increase in HGH and HP. With increased Mg++ concentrations in the medium HGH, ACTH, and HP release decreased. The removal of estradiol from the medium results in increased release of FSH, LH, HGH and ACTH while the HP release was greatly decreased. Various doses of TRH decreased HP release and altered the release pattern of HGH, FSH, and LH. Fetal hypothalamic tissue added to the medium increased HGH, FSH and LH release and extended the duration of release for these hormones while HP release was inhibited. Chick embryo extract was found to have a stimulating effect on the release of each hormones in vitro