Modifications in serum growth hormone concentration induced by sulpiride in acromegalic patients pretreated with dopamine, bromocriptine, and metergoline

M. Arosio, P. Moriondo, P. Travaglini, B. Ambrosi, P. Beck-Peccoz, F. C. Puglisi, F. Secchi, G. Faglia

Research output: Contribution to journalArticlepeer-review

Abstract

The modifications in serum GH concentrations after the administration of a dopamine antagonist [sulpiride (Slp); 100 mg, im] during the infusion of either saline or dopamine (DA; 4 μg/kg x min) were studied in 5 normal volunteers and 19 acromegalic patients. Slp was also given 3 h after the oral administration of 4 mg metergoline (Mtg) and 5 h after 2.5 mg bromocriptine (Brc) to 8 and 5 patients, respectively, and to 5 normal controls. All acromegalic patients had their GH responsiveness to TRH evaluated. No significant variations in serum GH were recorded in normal controls after DA-Slp, except for a slight and transient increase in some individuals occurring at 30-60 min during DA infusion. In acromegalics, no major GH variations were observed after Slp during saline administration, while during DA infusion there was a significant diminution in serum GH, from 27.6 ± 6.9 to 17.3 ± 5.0 (SE) ng/ml (P <0.002). This was followed by a prompt and significant rise in 13 cases (68.4%) after Slp injection (mean net increase over the mean basal value, 32.1 ± 9.6 ng/ml; P <0.05). Serum GH increased after TRH in 8 acromegalic patients (42%); all responded to DA-Slp. Five DA-Slp responders were retested after selective adenomectomy; 4 patients whose serum GH levels fell below 2 ng/ml became DA-Slp unresponsive, and the fifth patient, whose serum GH level fell from 53 to 6.5 ng/ml, remained DA-Slp responsive. After Mtg administration, Slp increased serum GH in 3 DA-Slp-responsive acromegalic patients but had no effect in 2 other DA-Slp responders, in 3 nonresponders, and in normal controls. After Brc, Slp did not increase serum GH levels in either normal controls or acromegalics, although 4 patients were DA-Slp responders. These data suggest that Slp directly stimulates GH secretion from the tumoral cells in the presence of DA. In fact, DA does not cross the blood-brain barrier, and DA-Slp responses disappeared after successful adenomectomy. The DA-Slp test, which appears to be reproducible, might be a useful tool for the evaluation of GH secretion in acromegaly. Mtg seems to display some dopaminergic activity on the tumoral cells. The absence of Slp-induced GH release after Brc could be explained by a more stable binding to dopaminergic receptors than DA itself.

Original languageEnglish
Pages (from-to)454-461
Number of pages8
JournalJournal of Clinical Endocrinology and Metabolism
Volume51
Issue number3
Publication statusPublished - 1980

ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology, Diabetes and Metabolism

Fingerprint Dive into the research topics of 'Modifications in serum growth hormone concentration induced by sulpiride in acromegalic patients pretreated with dopamine, bromocriptine, and metergoline'. Together they form a unique fingerprint.

Cite this