Growth hormone receptor expression and function in pituitary adenomas.

Objective And Design: Hypopituitarism, in particular GH deficiency, is prevalent in patients with clinically nonfunctioning pituitary adenomas (NFPAs) both before and after surgery. The factors regulating the growth of pituitary adenomas in general and residual tumour tissue in particular are not fully characterized, and the effect of GH and IGF-I on human pituitary cell proliferation has not previously been reported. In NFPA tissue from 14 patients we evaluated GH receptor (GHR) expression and signal transduction, and the effect of GH and IGF-I exposure on cell proliferation and hormone secretion in vitro.

Ectopic ACTH syndrome: discrepancy between somatostatin receptor status in vivo and ex vivo, and between immunostaining and gene transcription for POMC and CRH.

Objective: To characterize somatostatin receptor status in vivo and ex vivo and immunoreactivity and gene transcription for proopiomelanocortin (POMC) and corticotropin-releasing hormone (CRH) in a case of Cushing's syndrome caused by a sporadic metastatic medullary thyroid carcinoma (MTC).

Methods: (111)In octreoscan, analysis of tumorous mRNA transcripts for somatostatin receptor subtypes (SSTR) as well as for POMC and CRH.

Results: The tissue was intensely positive by (111)In octreoscan but expressed only SSTR 1, 3 and 5.