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 Christian, H. C. Articles by Buckingham, J. C. Search for Related Content PubMed PubMed Citation Articles by Christian, H. C. Articles by Buckingham, J. C.

Characterization and Localization of Lipocortin 1-Binding Sites on Rat Anterior Pituitary Cells by Fluorescence-Activated Cell Analysis/Sorting and Electron Microscopy¹

Department of Neuroendocrinology, Division of Neuroscience and Psychological Medicine, Imperial College School of Medicine, Charing Cross Hospital, London, United Kingdom W6 8RF; the Department of Biochemical Pharmacology, The William Harvey Research Institute, St. Bartholomew’s and the Royal London School of Medicine and Dentistry at Queen Mary and Westfield College (R.J.F.), London, United Kingdom EC1M 6BQ; and the Department of Human Anatomy, University of Oxford (J.F.M.), Oxford, United Kingdom OX1 3QX

Address all correspondence and requests for reprints to: Prof. Julia Buckingham, Department of Neuroendocrinology, Division of Neuroscience and Psychological Medicine, Imperial College School of Medicine, Charing Cross Hospital, Fulham Palace Road, London, United Kingdom W6 8RF. E-mail: j.buckingham{at}cxwms.ac.uk

Lipocortin 1 (LC1) is an important mediator of glucocorticoid action in the anterior pituitary gland, where it appears to act via cell surface binding sites to suppress peptide release. We have exploited a combination of fluorescence-activated cell (FAC) analysis/sorting and electron microscopy to detect, characterize, and localize LC1-binding sites on the surface of dispersed rat anterior pituitary cells, using human recombinant LC1 (hu-r-LC1) as a probe. High affinity (K_d = 14 ± 3 nM) hu-r-LC1-binding sites were detected on approximately 80% of anterior pituitary cells dispersed with collagenase. The binding characteristics of the ligand resembled those observed in leukocytes, in that it was saturable; concentration, Ca²⁺, and temperature dependent; and abolished by trypsin. Functional studies demonstrated an excellent correlation between the presence of the cell surface binding protein and the capacity of an anti-LC1 monoclonal antibody to abrogate the inhibitory actions of dexamethasone (10 nM) on the release of ACTH initiated in vitro by CRH-41 (1 nM). Morphological analysis of cells harvested by FAC sorting showed that 1) somatotrophs, corticotrophs, lactotrophs, thyrotrophs, and gonadotrophs were all included in the population expressing LC1 binding sites; and 2) the LC1-binding sites assume a punctate distribution across the cell surface. These data show that anterior pituitary cells express high affinity surface LC1-binding protein(s); they thus provide further evidence for a specific membrane mechanism of action of LC1 in regulating the endocrine function of the anterior pituitary.

This article has been cited by other articles:

				K. Ogasawara, H. Nogami, M. C. Tsuda, J.-A. Gustafsson, K. S. Korach, S. Ogawa, T. Harigaya, and S. Hisano Hormonal Regulation of Prolactin Cell Development in the Fetal Pituitary Gland of the Mouse Endocrinology, February 1, 2009; 150(2): 1061 - 1068. [Abstract] [Full Text] [PDF]

				C. D. John, V. Sahni, D. Mehet, J. F. Morris, H. C. Christian, M. Perretti, R. J. Flower, E. Solito, and J. C. Buckingham Formyl peptide receptors and the regulation of ACTH secretion: targets for annexin A1, lipoxins, and bacterial peptides FASEB J, April 1, 2007; 21(4): 1037 - 1046. [Abstract] [Full Text] [PDF]

				E. Davies, S. Omer, J. C. Buckingham, J. F. Morris, and H. C. Christian Expression and Externalization of Annexin 1 in the Adrenal Gland: Structure and Function of the Adrenal Gland in Annexin 1-Null Mutant Mice Endocrinology, March 1, 2007; 148(3): 1030 - 1038. [Abstract] [Full Text] [PDF]

				E. Davies, S. Omer, J. F Morris, and H. C Christian The influence of 17{beta}-estradiol on annexin 1 expression in the anterior pituitary of the female rat and in a folliculo-stellate cell line J. Endocrinol., February 1, 2007; 192(2): 429 - 442. [Abstract] [Full Text] [PDF]

				S. Omer, D. Meredith, J. F. Morris, and H. C. Christian Evidence for the Role of Adenosine 5'-Triphosphate-Binding Cassette (ABC)-A1 in the Externalization of Annexin 1 from Pituitary Folliculostellate Cells and ABCA1-Transfected Cell Models Endocrinology, July 1, 2006; 147(7): 3219 - 3227. [Abstract] [Full Text] [PDF]

				E. Solito, H. C. Christian, M. Festa, A. Mulla, T. Tierney, R. J. Flower, and J. C. Buckingham Post-translational modification plays an essential role in the translocation of annexin A1 from the cytoplasm to the cell surface FASEB J, July 1, 2006; 20(9): 1498 - 1500. [Abstract] [Full Text] [PDF]

				I. Huerta-Ocampo, H. C. Christian, N. M. Thompson, M. M. El-Kasti, and T. Wells The Intermediate Lactotroph: A Morphologically Distinct, Ghrelin-Responsive Pituitary Cell in the Dwarf (dw/dw) Rat Endocrinology, November 1, 2005; 146(11): 5012 - 5023. [Abstract] [Full Text] [PDF]

				E. Theogaraj, C. D. John, H. C. Christian, J. F. Morris, S. F. Smith, and J. C. Buckingham Perinatal Glucocorticoid Treatment Produces Molecular, Functional, and Morphological Changes in the Anterior Pituitary Gland of the Adult Male Rat Endocrinology, November 1, 2005; 146(11): 4804 - 4813. [Abstract] [Full Text] [PDF]

				K. M. Breen, C. A. Stackpole, I. J. Clarke, A. V. Pytiak, A. J. Tilbrook, E. R. Wagenmaker, E. A. Young, and F. J. Karsch Does the Type II Glucocorticoid Receptor Mediate Cortisol-Induced Suppression in Pituitary Responsiveness to Gonadotropin-Releasing Hormone? Endocrinology, June 1, 2004; 145(6): 2739 - 2746. [Abstract] [Full Text] [PDF]

				K. M. Breen and F. J. Karsch Does Cortisol Inhibit Pulsatile Luteinizing Hormone Secretion at the Hypothalamic or Pituitary Level? Endocrinology, February 1, 2004; 145(2): 692 - 698. [Abstract] [Full Text] [PDF]

				E. Solito, A. Mulla, J. F. Morris, H. C. Christian, R. J. Flower, and J. C. Buckingham Dexamethasone Induces Rapid Serine-Phosphorylation and Membrane Translocation of Annexin 1 in a Human Folliculostellate Cell Line via a Novel Nongenomic Mechanism Involving the Glucocorticoid Receptor, Protein Kinase C, Phosphatidylinositol 3-Kinase, and Mitogen-Activated Protein Kinase Endocrinology, April 1, 2003; 144(4): 1164 - 1174. [Abstract] [Full Text] [PDF]

				L. P. Chapman, M. J. Epton, J. C. Buckingham, J. F. Morris, and H. C. Christian Evidence for a Role of the Adenosine 5'-Triphosphate-Binding Cassette Transporter A1 in the Externalization of Annexin I from Pituitary Folliculo-Stellate Cells Endocrinology, March 1, 2003; 144(3): 1062 - 1073. [Abstract] [Full Text] [PDF]

				L. Chapman, A. Nishimura, J. C. Buckingham, J. F. Morris, and H. C. Christian Externalization of Annexin I from A Folliculo-Stellate-Like Cell Line Endocrinology, November 1, 2002; 143(11): 4330 - 4338. [Abstract] [Full Text] [PDF]

				H C Christian and J F Morris Rapid actions of 17{beta}-oestradiol on a subset of lactotrophs in the rat pituitary J. Physiol., March 1, 2002; 539(2): 557 - 566. [Abstract] [Full Text] [PDF]

				H. C. Christian, N. J. Rolls, and J. F. Morris Nongenomic Actions of Testosterone on a Subset of Lactotrophs in the Male Rat Pituitary Endocrinology, September 1, 2000; 141(9): 3111 - 3119. [Abstract] [Full Text] [PDF]

				A. D. Taylor, J. G. Philip, C. D. John, P. O. Cover, J. F. Morris, R. J. Flower, and J. C. Buckingham Annexin 1 (Lipocortin 1) Mediates the Glucocorticoid Inhibition of Cyclic Adenosine 3',5'-Monophosphate-Stimulated Prolactin Secretion Endocrinology, June 1, 2000; 141(6): 2209 - 2219. [Abstract] [Full Text] [PDF]

				V. Traverso, H. C. Christian, J. F. Morris, and J. C. Buckingham Lipocortin 1 (Annexin 1): A Candidate Paracrine Agent Localized in Pituitary Folliculo-Stellate Cells Endocrinology, September 1, 1999; 140(9): 4311 - 4319. [Abstract] [Full Text]

				H C Christian and J F Morris Rapid actions of 17{beta}-oestradiol on a subset of lactotrophs in the rat pituitary J. Physiol., March 1, 2002; 539(2): 557 - 566. [Abstract] [Full Text] [PDF]