| Research Abstract |
In order to clarify the mechanisms of specific functional expression of the anterior pituitary cells, we have investigated the expressoins of Pit-1 isoforms. Pit-1 beta and Pit-1 T by immunohistochemistry (IHC) and in situ hydridization (ISH). In the human pituitary and pituitary adenomas, our results suggested the involvement of Pit-1 beta in the differentiation toward GH and Pit-1 T toward TSH,respectively.
Recently, the synergetic roles of GH releasing hormone (GHRH) and receptor for estrogen (ER), for thyroid hormone (TR) and for retinoid (RAR,RXR) with Pit-1 have been reported and emphasized. By Combined ISH-IHC histochemical staining, ER and RXR were colocalized with Pit-1 in the same cells. In prolactin secreting adenomas, Pit-1 and ER were colocalized in the same cells. Regarding GHRH receptor (GHRHR), we are in the process of introducing in situ RT-PRCR in order to detect trivial amount of GHRHR mRNA.Preliminary, GHRHR has been co-localized in the same cells of the hyperplastic pituitary gland in hGHRH transgenic rats.
Our studies have suggested the synergetic effects of Pit-1 isoforms and various receptors in the specific functional expressions of the anterior pituitary cell and in the pituitary adenoma cells. More detailed mechanisms remain to be investigated in the future investigations.
|
