GONADOTROPIN Edited by Jorge Vizcarra Gonadotropin http://dx.doi.org/10.5772/2918 Edited by Jorge Vizcarra Contributors Jorge Vizcarra, Clay A. Lents, C. Richard Barb, Gary J. Hausman, Rosaria Meccariello, Rosanna Chianese, Silvia Fasano, Riccardo Pierantoni, María Ester Celis, Mark A. Crowe, Michael P. Mullen, Dara J. Cooke, Mark A. Crow Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2013 InTech All chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. Notice Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published chapters. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Dimitri Jelovcan Typesetting InTech Prepress, Novi Sad Cover InTech Design Team First published February, 2013 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechopen.com Gonadotropin, Edited by Jorge Vizcarra p. cm. ISBN 978-953-51-1006-4 Contents Preface VII Chapter 1 Contribution of Chicken GnRH-II and Lamprey GnRH-III on Gonadotropin Secretion 1 Jorge Vizcarra Chapter 2 Role of Adipose Secreted Factors and Kisspeptin in the Metabolic Control of Gonadotropin Secretion and Puberty 25 Clay A. Lents, C. Richard Barb and Gary J. Hausman Chapter 3 Endocannabinoids and Kisspeptins: Two Modulators in Fight for the Regulation of GnRH Activity 57 Rosaria Meccariello, Rosanna Chianese, Silvia Fasano and Riccardo Pierantoni Chapter 4 Influence of Neuropeptide – Glutamic Acid-Isoleucine (NEI) on LH Regulation 89 María Ester Celis Chapter 5 Regulation and Differential Secretion of Gonadotropins During Post Partum Recovery of Reproductive Function in Beef and Dairy Cows 107 Mark A. Crowe and Michael P. Mullen Chapter 6 Relative Roles of FSH and LH in Stimulation of Effective Follicular Responses in Cattle 125 Mark A. Crowe and Michael P. Mullen Chapter 7 Regulation and Function of Gonadotropins Throughout the Bovine Oestrous Cycle 143 Mark A. Crowe and Michael P. Mullen Chapter 8 Structural and Functional Roles of FSH and LH as Glycoproteins Regulating Reproduction in Mammalian Species 155 Michael P. Mullen, Dara J. Cooke and Mark A. Crow Preface It is widely recognized that proper gonadal function depends on the coordinated action of multiple factors influencing the synthesis and secretion of gonadotropin hormones. The term gonadotropin derives from the combination of gonas (from Greek gonos or “seed”) and tropin (from Greek trepein or “to change”). Thus, gonadotropins are protein hormones that have the ability to change gonadal function. Although the word gonadotrophin is also used in scientific literature, the etymological derivation of this alternative spelling is different. Trophic (from Greek trophe or “nutrition”) implies a nurturing action, a function that is not consistent with the nature these protein hormones. Thus, from a physiological point of view, the term gonadotropin better describes the main emphasis of this book. The gonadotropin family includes luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secreted from the pituitary gland. These hormones are composed of two dissimilar subunits: an alpha subunit and a beta subunit. Within species, the alpha subunits are nearly identical; however, the beta subunits are specific for each hormone. When the subunits are combined, to form a noncovalently associated heterodimer, the beta subunit provides a unique spatial conformation that ensures a high affinity interaction with their membrane receptors; thus, the biological specificity of each hormone. Each subunit is the product of separate genes. Genes are translated and subsequently glycosylated before packaging and secretion from the Golgi apparatus. Glycosylation is an enzymatic process that attaches poly- or oligosaccharides (glycans) to the different subunits. Thus, gonadotropins are also part of the glycoprotein hormone family that includes other hormones such as thyroid- stimulation hormone (TSH). In addition, some species also secrete chorionic gonadotropins during pregnancy. Chorionic gonadotropins are also heterodimeric glycoprotein than can have different degrees of LH and FSH biological activity in horses (eCG), humans (hCG), and other primates. Synthesis and secretion of LH and FSH takes place in the gonadotropes of the pituitary gland (adenohypophysis). The hypothalamus, in turn, controls the secretion of gonadotropins by the pulsatile secretion of gonadotropin releasing hormone (GnRH). Therefore, the neuroendocrine linkage of the hypothalamic-pituitary-gonadal axis provides an integrated system responsible for proper reproductive performance, including gamete development and sex steroids secretion. VIII Preface The scope and objective of this book is to provide researchers and graduate students with an updated review of the control mechanisms associated with the synthesis and secretion of gonadotropins. From a practical point of view, the book also provides relevant information that integrates reproductive performance of domestic species. A dedicated panel of authors was assembled to address these topics, aiming to provide a cutting edge platform to those interested in reproductive physiology and endocrinology. The book is organized in eight chapters. The first four chapters are dedicated to the control of gonadotropin secretion via GnRH and GnRH isoforms, Kisspeptin, Endocannabinoids and neuropeptide–glutamic acid-isoleucine. A series of three interrelated chapters summarize the regulation of gonadotropin secretion in cattle, and an additional chapter is devoted to the functions of gonadotropin-related structural features. Putting this book together has been an enjoyable task. I would like to thank all the authors for their patience throughout the editorial process, and most importantly for their valuable contribution. Dr. Jorge Vizcarra Department of Food and Animal Science, Alabama A&M University, USA [...]... Lamprey GnRH-III on Gonadotropin Secretion Jorge Vizcarra Additional information is available at the end of the chapter http://dx.doi.org/10.5772/47863 1 Introduction Proper gonadal function in mammals depends on gonadotropins secreted from the pituitary gland in a pulsatile manner The hypothalamus, in turn, controls the secretion of gonadotropins by the pulsatile secretion of gonadotropin releasing... independently (Vizcarra et al., 2004) Contribution of Chicken GnRH-II and Lamprey GnRH-III on Gonadotropin Secretion 5 Figure 2 Pulsatile secretion of LH and FSH in plasma of four birds Blood samples were obtained every 10-min for 8 h Asterisks indicate the presence of a pulse of LH or FSH, as determined by Pulsar Adapted from (Vizcarra et al., 2004) 6 Gonadotropin Both cGnRH-I and -II stimulates gonadotropin. .. nonmammalian gonadotropin- releasing hormone receptor in cell surface expression, ligand binding, and receptor phosphorylation and internalization Molecular Pharmacology 56: 12291237 Bowen, A., S Khan, L Berghman, J D Kirby, R P Wettemann, and J A Vizcarra 2006 Immunization of pigs against chicken gonadotropin- releasing hormone-II and lamprey gonadotropin- releasing hormone-III: effects on gonadotropin. .. Isolation and characterization of chicken hypothalamic luteinizing hormone-releasing hormone Biochem Biophys Res Commun 107: 820-827 Miyamoto, K., Y Hasegawa, M Nomura, M Igarashi, K Kangawa, and H Matsuo 1984 Identification of the second gonadotropin- releasing hormone in chicken hypothalamus: evidence that gonadotropin secretion is probably controlled by two distinct gonadotropin- releasing hormones in avian... the GnRH pulse generator is available by measuring plasma LH concentrations in frequent samples or in pituitary extracts (Chou and Johnson, 1987; Sharp and Gow, 1983; Wilson and Sharp, 1975) In addition, we have reported the episodic nature of gonadotropin secretion in the mature fowl (Vizcarra et al., 2004) Gonadotropin secretion in chickens is characterized by a pulsatile pattern with LH pulses being... other rodents by reverse-phase-HPLC followed by RIA, or by performing two successive HPLC steps to prevent the coelution of GnRH peptides (Gautron et al., 2005; Montaner et al., 1999; Montaner et al., 2001) When rats were infused (i.v.) with doses of lGnRH-III or mGnRH, gonadotropin secretion was increased in a dose-dependent manner with a greater increase in LH than FSH concentrations The potency of... Nett 1997 Effect of gonadotropin- releasing hormone (GnRH) pulse frequency on serum and pituitary concentrations of luteinizing hormone and follicle-stimulating hormone, GnRH receptors, and messenger ribonucleic acid for gonadotropin subunits in cows Endocrinology 138: 594-601 24 Gonadotropin Vizcarra, J., M Rhoads, C Hsu, J Washington, J Morgan, J Yang, H Tang, J Warren, and J Kirby 2000 Effect of immunization... immunization against chicken gonadotropin releasing hormone –I (cGnRH-I) and cGnRH-II on reproductive function in adult broiler breeder males Poultry Sci 79: Abs 343 Vizcarra, J A., D L Kreider, and J D Kirby 2004 Episodic gonadotropin secretion in the mature fowl: serial blood sampling from unrestrained male broiler breeders (Gallus domesticus) Biology of Reproduction 70: 1798-1805 Vizcarra, J A., S L Karges,... polymorphism of native gonadotropin- releasing hormone (GnRH) is restricted to mammalian GnRH and [hydroxyproline9] GnRH in the developing rat brain Neuroendocrinology 81: 69-86 Guillemin, R., and B Rosenberg 1955 Humoral hypothalamic control of anterior pituitary: a study with combined tissue cultures Endocrinology 57: 599-607 Guillemin, R 2005 Hypothalamic hormones a.k.a hypothalamic releasing factors... 2003 Gonadotropin- releasing hormone antagonists Current Opinion in Pharmacology 3: 660-666 Heredi-Szabo, K., R F Murphy, and S Lovas 2006 Is lGnRH-III the most potent GnRH analog containing only natural amino acids that specifically inhibits the growth of human breast cancer cells? Journal of Peptide Science 12: 714-720 18 Gonadotropin Hiney, J K., S A Sower, W H Yu, S M McCann, and W L Dees 2002 Gonadotropinreleasing . GONADOTROPIN Edited by Jorge Vizcarra Gonadotropin http://dx.doi.org/10.5772/2918 Edited by Jorge Vizcarra Contributors Jorge. hard copies can be obtained from orders@intechopen.com Gonadotropin, Edited by Jorge Vizcarra p. cm. ISBN 978-953-51-1006-4 Contents