ABSTRACT

Contents 2.1 Introduction ...............................................................................................31 2.2 Structure ....................................................................................................32 2.3 Control of GnRH Release ..........................................................................32 2.4 GnRH Action in the Gonadotrope ............................................................33 2.5 GnRH Variants and Receptor Genes ........................................................ 34 2.6 Potential Functions of GnRH I and GnRH II ...........................................36 2.7 Functional GnRH Receptor in Humans ....................................................37 Acknowledgements ..............................................................................................38 References ...........................................................................................................38

(FSH); its output into hypophyseal portal vessel blood under experimental and physiological conditions correlates well with the output of LH from the anterior pituitary gland. The decapeptide, now known as GnRH (gonadotropin-releasing hormone), is the primary hypothalamic signal necessary for the structural and functional integrity of the pituitary gonadotropes; regulates the synthesis, glycosylation, and secretion of LH and FSH; and has the apparently unique quality of being able to increase the responsiveness of the pituitary to itself (the priming effect of GnRH) which, in turn, stimulates gonadal steroidogenesis and gametogenesis (Fink 1988). The purification, sequencing and synthesis of the decapeptide by Schally in 1971 is considered a milestone in discovering the role of neuroendocrine system in reproduction (Matsuo et al. 1971).