Somatostatin cells in human somatotropic adenomas

Abstract

Data from our group have shown that the human adenomatous and normal anterior pituitary may be the source of somatostatin (SRIH). SRIH-producing cells were identified in two somatotropic adenomas. Immunoreactive SRIH cells were present in both cases. In case 2, material was available for RNA studies, in situ hybridization and electron microscopy. The size of the transcript identified by Northern blot analysis was identical to that of hypothalamic SRIH mRNA. In situ hybridization showed that the SRIH gene was expressed in a cell subset superimposable to that identified by immunocytochemistry. Co-localization studies revealed that SRIH and growth hormone (GH) immunoreactivities were not present in the same cells. Ultrastructural immunogold labelling showed that SRIH cells had features distinct from those of the somatotropes. The results confirm that the somatotropic adenomas have the ability to synthesize SRIH, indicate that SRIH expression is restricted to a subset of adenoma cells different from GH-producing cells, and imply that SRIH cells are involved in paracrine regulation of neighbouring somatotropes.

Stimulatory effect of gonadotropin-releasing hormone (GnRH) on in vitro prolactin secretion and presence of GnRH specific receptors in a subset of human prolactinomas

“…Indirect immunoperoxidase was performed on deparaffinized sections using the following rabbit polyclonal antibodies and mouse monoclonal antibodies at the specified dilutions (25). Polyclonal antibodies included: anti-PRL antiserum (batch 51-53-55, from Dr C Rougeot, Institut Pasteur, France) 1:500, anti-GH antiserum (batch 5976, from Dr Y Tillet, Nouzilly, France) 1:2000 and anti-/3-LH antiserum (AFP 54372 NIDDK, Bethesda, USA) 1:1000.…”

Autocrine and Paracrine Effects of Peptides on Human Pituitary Cells

“…which may either be colocalized with a pituitary hormone [12. 13] or be in specific cells as it is for SRIH [14], Mes senger RNAs as well as translation products are not differ ent from what has already been characterized in the hypo thalamus. and arises now as a new concept, called by Krisch [15] 'the paraneuron concept' which compares in many points neurons and some endocrine cells with a common embryologic origin, the neural crest.…”