This Article Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by NAKAGAWA, K. Articles by KUBO, M. Search for Related Content PubMed PubMed Citation Articles by NAKAGAWA, K. Articles by KUBO, M.

Effect of Dexamethasone on Growth Hormone (GH) Response to Growth Hormone Releasing Hormone in Acromegaly^*

Second Department of Medicine, Hokkaido University School of Medicine, Sapporo, 060 Japan Sapporo, 060 Japan

The effect of dexamethasone on the GH responseto GH-releasing hormone (GHRH) was studied in vivoin six patients with acromegaly as well as in vitro in monolayercultures of GH-secreting pituitary tumor cells obtained fromthree of these patients. Oral administration of 9 mg/day dexamethasonefor 2 days decreased plasma GH responses to ivinjection of 100 µg GHRH-(1–44 amide) in all six patients. Bloodglucose levels were significantly increased, while plasma somatomedin-C levels were significantly decreased by this regimen ofdexamethasone treatment. On the other hand, 2-day pretreatmentwith 50 nM dexamethasone of monolayer cultures of pituitaryadenoma cells potentiated GH release basally and/or inresponse to 100 pM to 1 nM GHRH in vitro. These resultsindicate that the potentiating action of 2-day treatment ofdexamethasone in vitro is overwhelmed in vivo by some extrapituitaryaction, probably on the central nervous system, ofglucocorticoids in patients with acromegaly.

^* This work was supported in part by the Research Grants for the Intractable Diseases from the Ministry of Health and Welfare and aresearch grant from the Ministry of Education, Science, and Cultureof Japan.

Received June 13, 1984.

This article has been cited by other articles:

				R. M Luque, M. D Gahete, R. J Valentine, and R. D Kineman Examination of the direct effects of metabolic factors on somatotrope function in a non-human primate model, Papio anubis. J. Mol. Endocrinol., August 1, 2006; 37(1): 25 - 38. [Abstract] [Full Text] [PDF]