Growth hormone and prolactin responses to corticotrophin-releasing- hormone in patients with Cushing's disease: A paracrine action of the adenomatous corticotrophic cells?

P. Loli, E. Boccardi, V. Branca, M. Bramerio, M. Barberis, M. Losa, M. T. Terreni, S. Lodrini, B. Pollo, F. Vignati

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Abstract

OBJECTIVE: In patients with Cushing's disease multi-hormonal responses to ovine corticotrophin releasing hormone (oCRH) have been detected in blood from inferior petrosal sinuses. This finding has been explained by co- secretion of other hormones, in addition to ACTH, by the pituitary adenoma itself or by paracrine effects exerted by the adenoma on normal periadenomatous pituitary cells. To assess these hypotheses we compared the presence of a CRH induced GH and/or PRL response during inferior petrosal sinus sampling to the immunohistochemical detection of PRL and GH in adenomatous tissue removed from patients with Cushing's disease. PATIENTS AND MEASUREMENTS: Twenty-two patients with Cushing's disease and two patients with ectopic ACTH syndrome due to a bronchial carcinoid were studied; each patient had undergone preoperative inferior petrosal sinus sampling for diagnostic purposes with determination of GH and PRL in addition to ACTH, before and after administration of oCRH. Immunohistochemical studies for ACTH, GH and PRL detection were carried out on adenomatous tissue removed at surgery in the patients with pituitary dependent Cushing's disease and on the carcinoid tumours from the two patients with ectopic ACTH syndrome. RESULTS: All pituitary adenomas immunostained for ACTH, and four adenomas immunostained for GH or PRL in addition to ACTH. A PRL increase in the inferior petrosal sinus after oCRH administration was found in 11 of 22 patients, but none of their tumours immunostained for PRL. Immunostaining for PRL was found in the pituitary tumours from two patients but in neither patient was there a PRL response after oCRH. A GH response was found in 13 of 20 patients in whom it was sought; no patient showed immunostaining in their tumour. GH immunostaining was found in two tumours but in neither patient was there a GH response after oCRH. The oCRH-induced increase of GH and PRL was always recorded in the dominant inferior petrosal sinus. The ACTH response to oCRH was significantly higher in patients who showed oCRH induced increases in GH and/or PRL than in patients who did not, both in terms of area under the response-curve (22 032 ± 9876 vs. 4371 ± 2870 ng/l/10 min; P

Original languageEnglish
Pages (from-to)433-439
Number of pages7
JournalClinical Endocrinology
Volume49
Issue number4
DOIs
Publication statusPublished - 1998

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ASJC Scopus subject areas

  • Endocrinology

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