Thyrotropin-releasing Hormone Stimulation of Adrenocorticotropin Production by Mouse Pituitary Tumor Cells in Culture

Gershengorn, Marvin C.; Arevalo, Carlos O.; Geras, Elizabeth; Rebecchi, Mario J.

doi:10.1172/jci109792

Cited by 10 publications

(1 citation statement)

References 36 publications

(48 reference statements)

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“…Interestingly, two different mammalian tumor cell lines have also been shown to respond to TRH. In the rat GH3 cells the tripeptide stimulates prolactin release [1,40], and it also stimulates secretion from cells of a human ACTH-producing ectopic tumor [3,10,15]. Therefore, this peptide seems to have a broad spectrum of potential activities.…”

Section: Discussionmentioning

confidence: 99%

Assessment of TRH as a potential MSH release stimulating factor in Xenopus laevis

et al. 1987

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This study considers the possible involvement of the tripeptide TRH (thyrotropin releasing hormone) in the physiological regulation of melanophore stimulating hormone (MSH) secretion from the pars intermedia of the toad, Xenopus laevis. TRH was shown to stimulate release of MSH from superfused neurointermediate lobes obtained from white-background adapted animals, but had no effect on secretion from lobes of black-background adapted animals. Immunohistochemical analysis revealed a rich TRH-containing neuronal network terminating in the neural lobe of the Xenopus pituitary. Plasma levels of TRH, determined with a specific radioimmunoassay, proved to be extremely high and no significant difference in this level could be found between white- and black-adapted animals. Plasma TRH probably originates from the skin, and our results show that its concentration is within the effective concentration range established for this peptide in stimulating MSH release from the pars intermedia. Therefore, while both our superfusion and immunohistochemical results argue favourably for a function of TRH in the regulation of MSH secretion, we conclude that, in any regulatory role, it would likely have to function within the pars intermedia at concentrations exceeding the high plasma values. While TRH could be involved in short-term activation of the secretory process in white-background adapted animals or in animals undergoing the initial stages of black background adaptation, our results indicate that this peptide may have no function in the maintenance of secretion from the pars intermedia of animals fully adapted to black background.

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