In vitro effect of dopamine on growth hormone (GH) release from human GH-secreting pituitary adenomas

A. Spada, A. Sartorio, M. Bassetti, G. Pezzo, G. Giannattasio

Research output: Contribution to journalArticle

Abstract

The effect of dopamine (DA) on GH release was studied in monolayer cultures obtained from 21 GH-secreting pituitary adenomas. DA at a concentration of 10 -6 M inhibited GH release in 13 adenomas (group I: inhibition from 27-74%), had no effect in 3 (group II), and elicited a marked stimulation in 5 (group III: stimulation from 62-170%). The adenomas of acromegalic patients which were preoperatively responsive to DA infusion (4 μg/kg.min) all fell into group I, whereas adenomas from patients not responsive to DA in vivo fell into groups II and III. The dose dependency of the effect of DA on GH secretion was studied in groups I and III. In group I adenomas the maximal inhibition was from 32-76% between 10 -7 and 2 x 10 -5 M DA. At high concentrations DA elicited a stimulatory effect. In group III adenomas the maximal stimulation was from 95-310% between 1- -7 and 1- -5 M DA. The dopaminergic ergot derivative CH 29-717 was as potent as DA in inhibiting GH release but, in contrast to DA, was nearly ineffective in stimulating the secretion of the hormone. We hypothesize that the different in vitro responsiveness of GH-secreting pituitary adenomas to DA could be due to the presence of multiple forms of DA receptors.

Original languageEnglish
Pages (from-to)734-740
Number of pages7
JournalJournal of Clinical Endocrinology and Metabolism
Volume55
Issue number4
Publication statusPublished - 1982

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ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology, Diabetes and Metabolism

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