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 Nogami, H. Articles by Kawamura, K. Search for Related Content PubMed PubMed Citation Articles by Nogami, H. Articles by Kawamura, K.

Involvement of Glucocorticoid-Induced Factor(s) in the Stimulation of Growth Hormone Expression in the Fetal Rat Pituitary Gland in Vitro¹

Department of Anatomy (H.N., K.K.), School of Medicine, Keio University, Tokyo 160, Japan; Department of Regulation Biology (K.I.), Faculty of Science, Saitama University, Saitama 338, Japan

Address all correspondence and requests for reprints to: Haruo Nogami, Ph.D., Department of Anatomy, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160, Japan.

The mechanism by which glucocorticoids induce GH expression between embryonic days 18 and 19 (E18–19) in the fetal rat pituitary gland was examined with an in vitro organ culture system. Twenty-four hour incubation of E18 pituitary glands in serum-free medium containing either dexamethasone (DEX, 5–50 nM) or corticosterone (0.5–5 µM) resulted in a conspicuous accumulation of GH messenger RNA (mRNA), whereas no spontaneous expression of GH mRNA was noted without glucocorticoid. Triiodothyronine (1 nM) alone weakly induced GH mRNA but increased the effect of DEX 2-fold. The GH mRNA accumulation was not observed after 5 or 10 h incubation with DEX. However, a 10-h incubation with DEX followed by 14 h chase incubation without DEX resulted in apparent induction of GH mRNA. The induction of GH mRNA by DEX was completely inhibited by puromycin.

These data, taken as a whole, suggest that the induction of GH mRNA by DEX in the fetal pituitary gland is not a direct effect of DEX on the GH gene but is mediated by a factor that is synthesized in the pituitary gland in response to DEX. Both immunoblot and RNase protection assays suggested that this factor is not pit-1, which is known to be required for GH mRNA expression.

This article has been cited by other articles:

				L. E Ellestad, S. A Malkiewicz, H D. Guthrie, G. R Welch, and T. E Porter Expression and regulation of glucocorticoid-induced leucine zipper in the developing anterior pituitary gland J. Mol. Endocrinol., February 1, 2009; 42(2): 171 - 183. [Abstract] [Full Text] [PDF]

				S. A. Jenkins, M. Muchow, M. P. Richards, J. P. McMurtry, and T. E. Porter Administration of Adrenocorticotropic Hormone during Chicken Embryonic Development Prematurely Induces Pituitary Growth Hormone Cells Endocrinology, August 1, 2007; 148(8): 3914 - 3921. [Abstract] [Full Text] [PDF]

				A. H. Y. Kwok, Y. Wang, C. Y. Wang, and F. C. Leung Cloning of Chicken Glucocorticoid Receptor (GR) and Characterization of its Expression in Pituitary and Extrapituitary Tissues Poult. Sci., February 1, 2007; 86(2): 423 - 430. [Abstract] [Full Text] [PDF]

				L. E. Ellestad, W. Carre, M. Muchow, S. A. Jenkins, X. Wang, L. A. Cogburn, and T. E. Porter Gene expression profiling during cellular differentiation in the embryonic pituitary gland using cDNA microarrays Physiol Genomics, May 16, 2006; 25(3): 414 - 425. [Abstract] [Full Text] [PDF]

				I. Bossis, S. Nishimura, M. Muchow, and T. E. Porter Pituitary Expression of Type I and Type II Glucocorticoid Receptors during Chicken Embryonic Development and Their Involvement in Growth Hormone Cell Differentiation Endocrinology, July 1, 2004; 145(7): 3523 - 3531. [Abstract] [Full Text] [PDF]

				X. Fu and T. E. Porter Glucocorticoid Induction of Lactotrophs and Prolactin Gene Expression in Chicken Embryonic Pituitary Cells: A Delayed Response Relative to Stimulated Growth Hormone Production Endocrinology, March 1, 2004; 145(3): 1322 - 1330. [Abstract] [Full Text] [PDF]

				L. Liu, C. E. Dean, and T. E. Porter Thyroid Hormones Interact with Glucocorticoids to Affect Somatotroph Abundance in Chicken Embryonic Pituitary Cells in Vitro Endocrinology, September 1, 2003; 144(9): 3836 - 3841. [Abstract] [Full Text] [PDF]

				I. Bossis and T. E. Porter Ontogeny of Corticosterone-Inducible Growth Hormone-Secreting Cells during Chick Embryonic Development Endocrinology, July 1, 2000; 141(7): 2683 - 2690. [Abstract] [Full Text] [PDF]

				H. Nogami, K. Inoue, H. Moriya, A. Ishida, S. Kobayashi, S. Hisano, M. Katayama, and K. Kawamura Regulation of Growth Hormone-Releasing Hormone Receptor Messenger Ribonucleic Acid Expression by Glucocorticoids in MtT-S Cells and in the Pituitary Gland of Fetal Rats Endocrinology, June 1, 1999; 140(6): 2763 - 2770. [Abstract] [Full Text]

				C. E. Dean and T. E. Porter Regulation of Somatotroph Differentiation and Growth Hormone (GH) Secretion by Corticosterone and GH-Releasing Hormone during Embryonic Development Endocrinology, March 1, 1999; 140(3): 1104 - 1110. [Abstract] [Full Text]

				B. Morpurgo, C. E. Dean, and T. E. Porter Identification of the Blood-Borne Somatotroph-Differentiating Factor during Chicken Embryonic Development Endocrinology, November 1, 1997; 138(11): 4530 - 4535. [Abstract] [Full Text] [PDF]