Preface

Growth hormone (GH) is synthesized and secreted daily by anterior pituitary cells called somatotrophs. GH has a role to play in various physiological processes. It is fundamental for the normal physical growth of children and, irrespective of the age of the individual, it is necessary for the proper functionality of the metabolic responses. GH stimulates the synthesis of proteins and increases the breakdown of fat mass to generate the energy necessary for tissue growth. It also counterpoints the action of insulin. While it appears to act on different tissues, part of its effect is mediated by the release of insulin-like growth factor-1 (IGF-1). IGF-1 can mimic the action of insulin, but its primary action is also the stimulation of growth.

Some individuals are affected by abnormalities in GH secretion, which can be either deficient or excessive. Production of GH in individuals can be stimulated by different types of physical exercises, and GH deficiency can be treated with direct administration of GH into individuals. GH deficiency is also a cause of short stature and dwarfism in some individuals. GH deficiency that persists into adulthood is associated with various undesirable clinical conditions, such as fatigue, decreased energy, decreased muscle strength, decreased muscle mass, thin and dry skin, increased adipose tissue, which favors obesity, and decreased bone density. Excess GH production may be due to a benign tumor of the somatotroph cells of the pituitary gland, as well as tumor of the lung or of the pancreatic islets. Excess of GH may lead to extreme height (gigantism) and features of acromegaly.

This book, which is in three sections, introduces the reader to the biochemistry of growth hormone and its relevance to human beings. Section 1 highlights the relevance of the relationship between GH, obesity, and physical exercise. Section 2 consists of two chapters: "Growth Hormone Gene Family and Its Evolution" and "Pituitary Growth Hormone Secretion and Cell Growth Hormone Production: Regulation of Their Secretion and Their Signaling Pathways". Section 3 discusses the types of interventions in three chapters: "Growth Hormone and Insulin-like Growth Factor-1 in Children with Cholestatic Diseases and Pediatric Liver Transplantation", "Carbohydrate Metabolism in Growth Hormone Therapy for Children" and "Obesity: The Relationship between Growth Hormone and Exercises".

The editors would like to thank Author Service Manager Maja Bozicevic at IntechOpen for her amazing work, and for her patience and assistance throughout the preparation of this book.
