This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map 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 Pals, K. Articles by Denef, C. Search for Related Content PubMed PubMed Citation Articles by Pals, K. Articles by Denef, C.

A Pituitary Cell Type Coexpressing Messenger Ribonucleic Acid of Proopiomelanocortin and the Glycoprotein Hormone -Subunit in Neonatal Rat and Chicken: Rapid Decline with Age and Reappearance in Vitro under Regulatory Pressure of Corticotropin-Releasing Hormone in the Rat

Laboratory of Cell Pharmacology, University of Leuven, Medical School, B-3000, Leuven, Belgium

Address all correspondence and requests for reprints to: Prof. Carl Denef, Laboratory of Cell Pharmacology, University of Leuven, Medical School, Campus Gasthuisberg (O & N), B-3000 Leuven, Belgium. E-mail: Carl.Denef{at}med.kuleuven.be

Promiscuous hormone mRNA expression in the pituitary remains poorly understood. We examined by means of RT-PCR and immunostaining whether glycoprotein hormone -subunit (GSU) could be coexpressed with proopiomelanocortin (POMC) in vivo and under pressure of CRH in vitro. Cells coexpressing GSU and POMC mRNA amounted to 2.6% of the cells in ex vivo rat pituitary at birth [postnatal d 1 (P1)], fell to much lower level at P14, and were undetectable in adulthood. In cultured pituitary aggregates of P14 rats, GSU/POMC cells remained scarce but represented up to 6.6% after chronic treatment with CRH but not leukemia inhibitory factor. CRH was less effective in aggregates from P1 and adult rats. The total GSU population ex vivo at P1 was two times smaller than at P14, but in culture it expanded 2.5 times, concomitantly with a reciprocal change in POMC cell abundance. Tpit transcripts were detected in POMC-only and GSU/POMC cells but not in GSU-only cells. Cells coexpressing GSU and POMC mRNA were relatively abundant in P14 chicken pituitary and aggregate cultures, but occurrence was not affected by CRH. Immunostaining showed GSU and POMC colocalization in sporadic cells in intact rat pituitary and CRH-treated cultures at P1 but not at P14 and adult age. The data demonstrate the occurrence of cells coexpressing GSU and POMC in rat and chicken pituitary. The developmental dynamics of this cell population and its response to CRH in vitro in the rat suggest a relationship of these cells with the embryonic branching of the POMC and GSU cell lineages and their mutually opposite developmental course during early postnatal life.

This article has been cited by other articles:

				K. Janssens, O. Krylyshkina, N. Hersmus, H. Vankelecom, and C. Denef {beta}1-Adrenoceptor Expression in Rat Anterior Pituitary Gonadotrophs and in Mouse {alpha}T3-1 and L{beta}T2 Gonadotrophic Cell Lines Endocrinology, May 1, 2008; 149(5): 2313 - 2324. [Abstract] [Full Text] [PDF]