This Article 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 Kamegai, J. Articles by Oikawa, S. Search for Related Content PubMed PubMed Citation Articles by Kamegai, J. Articles by Oikawa, S.

Regulation of the Ghrelin Gene: Growth Hormone-Releasing Hormone Upregulates Ghrelin mRNA in the Pituitary

Department of Medicine Nippon Medical School, Tokyo 113-8603, Japan

Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor (GHS-R), was originally purified from the rat stomach. Ghrelin specifically releases GH following intravenous administration, and its GH-releasing activity in vivo is dependent on growth hormone-releasing hormone (GHRH). We previously reported that the expression of the GHS-R gene in the pituitary is developmentally regulated and GHRH infusion increases pituitary levels of GHS-R mRNA. Ghrelin mRNA and peptide have recently been detected in rat and human pituitaries. However, the regulation of the ghrelin gene in the pituitary is unknown. In this study, pituitary levels of ghrelin mRNA were measured with the reverse transcriptase-polymerase chain reaction in male rats at embryonic day (e)18 and postnatal days 1, 10, 30, and 75. The highest concentrations of ghrelin mRNA in the pituitary were observed at e18 and then they declined with age. The infusion of GHRH (10 µg/h, 4h) in freely-moving adult male rats resulted in a 1.9-fold increase in ghrelin mRNA levels relative to control rats (P < 0.05). These data indicated that the expression of the ghrelin gene in the pituitary is developmentally regulated and the pituitary ghrelin/GHS-R signaling system could modulate the regulation of GH secretion by GHRH.

This article has been cited by other articles:

				R. M. Luque, S. Park, and R. D. Kineman Severity of the Catabolic Condition Differentially Modulates Hypothalamic Expression of Growth Hormone-Releasing Hormone in the Fasted Mouse: Potential Role of Neuropeptide Y and Corticotropin-Releasing Hormone Endocrinology, January 1, 2007; 148(1): 300 - 309. [Abstract] [Full Text] [PDF]

				E. P. Zorrilla, S. Iwasaki, J. A. Moss, J. Chang, J. Otsuji, K. Inoue, M. M. Meijler, and K. D. Janda From the Cover: Vaccination against weight gain PNAS, August 29, 2006; 103(35): 13226 - 13231. [Abstract] [Full Text] [PDF]

				R. M. Luque, M. D. Gahete, U. Hochgeschwender, and R. D. Kineman Evidence that endogenous SST inhibits ACTH and ghrelin expression by independent pathways. Am J Physiol Endocrinol Metab, August 1, 2006; 291(2): E395 - E403. [Abstract] [Full Text] [PDF]

				J. D. Veldhuis, J. N. Roemmich, E. J. Richmond, and C. Y. Bowers Somatotropic and Gonadotropic Axes Linkages in Infancy, Childhood, and the Puberty-Adult Transition Endocr. Rev., April 1, 2006; 27(2): 101 - 140. [Abstract] [Full Text] [PDF]

				W. A. Blom, A. Stafleu, C. de Graaf, F. J Kok, G. Schaafsma, and H. F. Hendriks Ghrelin response to carbohydrate-enriched breakfast is related to insulin Am. J. Clinical Nutrition, February 1, 2005; 81(2): 367 - 375. [Abstract] [Full Text] [PDF]

				H. Ariyasu, K. Takaya, H. Iwakura, H. Hosoda, T. Akamizu, Y. Arai, K. Kangawa, and K. Nakao Transgenic Mice Overexpressing Des-Acyl Ghrelin Show Small Phenotype Endocrinology, January 1, 2005; 146(1): 355 - 364. [Abstract] [Full Text] [PDF]

				J. D. Veldhuis, J. T. Patrie, K. Frick, J. Y. Weltman, and A. Weltman Sustained Growth Hormone (GH) and Insulin-Like Growth Factor I Responses to Prolonged High-Dose Twice-Daily GH-Releasing Hormone Stimulation in Middle-Aged and Older Men J. Clin. Endocrinol. Metab., December 1, 2004; 89(12): 6325 - 6330. [Abstract] [Full Text] [PDF]

				J. Kamegai, H. Tamura, T. Shimizu, S. Ishii, A. Tatsuguchi, H. Sugihara, S. Oikawa, and R. D. Kineman The Role of Pituitary Ghrelin in Growth Hormone (GH) Secretion: GH-Releasing Hormone-Dependent Regulation of Pituitary Ghrelin Gene Expression and Peptide Content Endocrinology, August 1, 2004; 145(8): 3731 - 3738. [Abstract] [Full Text] [PDF]

				B. E. Salfen, J. A. Carroll, D. H. Keisler, and T. A. Strauch Effects of exogenous ghrelin on feed intake, weight gain, behavior, and endocrine responses in weanling pigs J Anim Sci, July 1, 2004; 82(7): 1957 - 1966. [Abstract] [Full Text] [PDF]

				J. E. Caminos, R. Nogueiras, M. Blanco, L. M. Seoane, S. Bravo, C. V. Alvarez, T. Garcia-Caballero, F. F. Casanueva, and C. Dieguez Cellular Distribution and Regulation of Ghrelin Messenger Ribonucleic Acid in the Rat Pituitary Gland Endocrinology, November 1, 2003; 144(11): 5089 - 5097. [Abstract] [Full Text] [PDF]

				N. Scanlan, L. Dufourny, and D. C. Skinner Somatostatin-14 Neurons in the Ovine Hypothalamus: Colocalization with Estrogen Receptor {alpha} and Somatostatin-28(1-12) Immunoreactivity, and Activation in Response to Estradiol Biol Reprod, October 1, 2003; 69(4): 1318 - 1324. [Abstract] [Full Text] [PDF]

				H. Tamura, J. Kamegai, T. Shimizu, S. Ishii, H. Sugihara, and S. Oikawa Ghrelin Stimulates GH But Not Food Intake in Arcuate Nucleus Ablated Rats Endocrinology, September 1, 2002; 143(9): 3268 - 3275. [Abstract] [Full Text] [PDF]