This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart 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 Moore, J. P. Articles by Hyde, J. F. Search for Related Content PubMed PubMed Citation Articles by Moore, J. P., Jr. Articles by Hyde, J. F.

Galanin within the Normal and Hyperplastic Anterior Pituitary Gland: Localization, Secretion, and Functional Analysis in Normal and Human Growth Hormone-Releasing Hormone Transgenic Mice¹

Department of Anatomy and Neurobiology, University of Kentucky College of Medicine, Lexington, Kentucky 40536

Address all correspondence and requests for reprints to: James F. Hyde, Ph.D., Department of Anatomy and Neurobiology, University of Kentucky College of Medicine, 800 Rose Street (MN224), Lexington, Kentucky 40536-0084. E-mail: jfhyde00{at}pop.uky.edu

Studies evaluating estrogen-induced anterior pituitary tumors revealed a strong direct correlation between expression of the peptide galanin and tumor growth. To evaluate further the potential roles of galanin in the hyperplastic pituitary, we used a model of estrogen-independent anterior pituitary tumor formation, the male human GH-releasing hormone (hGHRH) transgenic mouse. Pituitaries of hGHRH transgenic mice are characterized by a hyperplasia of somatotrophs and contain markedly elevated levels of galanin. We examined the population of galanin-producing pituitary cells in 4- to 6-month-old male hGHRH transgenic mice and their nontransgenic siblings. The percentage of galanin-containing pituitary cells was significantly increased within the anterior pituitaries of hGHRH transgenic mice. By using the cell immunoblot assay we found that the basal secretion of galanin and GH from individual pituitary cells of hGHRH transgenic mice was significantly greater than that from pituitary cells of nontransgenic mice. By modifying the cell immunoblot assay, we determined that somatotrophs from both hGHRH transgenic and normal mice that were positive for galanin immunoreactivity secreted significantly greater amounts of GH than those somatotrophs devoid of galanin immunoreactivity. Moreover, immunoneutralization of galanin significantly decreased GH secretion from pituitary cells obtained from hGHRH transgenic mice. Thus, we now show that the increased levels of galanin peptide within the hyperplastic pituitaries of hGHRH transgenic mice are due to an increase in the population of cells containing galanin, and that galanin participates in the augmented secretion of GH from hyperplastic proliferating pituitary cells.

This article has been cited by other articles:

				P. R. Le Tissier, D. F. Carmignac, S. Lilley, A. K. Sesay, C. J. Phelps, P. Houston, K. Mathers, C. Magoulas, D. Ogden, and I. C. A. F. Robinson Hypothalamic Growth Hormone-Releasing Hormone (GHRH) Deficiency: Targeted Ablation of GHRH Neurons in Mice Using a Viral Ion Channel Transgene Mol. Endocrinol., May 1, 2005; 19(5): 1251 - 1262. [Abstract] [Full Text] [PDF]

				D. S. Moons, S. Jirawatnotai, A. F. Parlow, G. Gibori, R. D. Kineman, and H. Kiyokawa Pituitary Hypoplasia and Lactotroph Dysfunction in Mice Deficient for Cyclin-Dependent Kinase-4 Endocrinology, August 1, 2002; 143(8): 3001 - 3008. [Abstract] [Full Text] [PDF]

				J. Schwartz Intercellular Communication in the Anterior Pituitary Endocr. Rev., October 1, 2000; 21(5): 488 - 513. [Abstract] [Full Text]

				J. P. Moore Jr., A. Cai, M. E. Hostettler, L. A. Arbogast, J. L. Voogt, and J. F. Hyde Pituitary Hormone Gene Expression and Secretion in Human Growth Hormone-Releasing Hormone Transgenic Mice: Focus on Lactotroph Function Endocrinology, January 1, 2000; 141(1): 81 - 90. [Abstract] [Full Text] [PDF]

				A. Cai, J. D. Hayes, N. Patel, and J. F. Hyde Targeted Overexpression of Galanin in Lactotrophs of Transgenic Mice Induces Hyperprolactinemia and Pituitary Hyperplasia Endocrinology, November 1, 1999; 140(11): 4955 - 4964. [Abstract] [Full Text]