Ghrelin: A 28-amino acid, acylated, orexigenic peptide that is a ligand for GROWTH HORMONE SECRETAGOGUE RECEPTORS. Ghrelin is widely expressed but primarily in the stomach in the adults. Ghrelin acts centrally to stimulate growth hormone secretion and food intake, and peripherally to regulate energy homeostasis. Its large precursor protein, known as appetite-regulating hormone or motilin-related peptide, contains ghrelin and obestatin.Receptors, Ghrelin: Transmembrane proteins that recognize and bind GHRELIN, a potent stimulator of GROWTH HORMONE secretion and food intake in mammals. Ghrelin receptors are found in the pituitary and HYPOTHALAMUS. They belong to the family of G-PROTEIN-COUPLED RECEPTORS.Peptide Hormones: Hormones synthesized from amino acids. They are distinguished from INTERCELLULAR SIGNALING PEPTIDES AND PROTEINS in that their actions are systemic.Appetite: Natural recurring desire for food. Alterations may be induced by APPETITE DEPRESSANTS or APPETITE STIMULANTS.Eating: The consumption of edible substances.Leptin: A 16-kDa peptide hormone secreted from WHITE ADIPOCYTES. Leptin serves as a feedback signal from fat cells to the CENTRAL NERVOUS SYSTEM in regulation of food intake, energy balance, and fat storage.Peptide YY: A 36-amino acid peptide produced by the L cells of the distal small intestine and colon. Peptide YY inhibits gastric and pancreatic secretion.Stomach: An organ of digestion situated in the left upper quadrant of the abdomen between the termination of the ESOPHAGUS and the beginning of the DUODENUM.Appetite Stimulants: Agents that are used to stimulate appetite. These drugs are frequently used to treat anorexia associated with cancer and AIDS.Human Growth Hormone: A 191-amino acid polypeptide hormone secreted by the human adenohypophysis (PITUITARY GLAND, ANTERIOR), also known as GH or somatotropin. Synthetic growth hormone, termed somatropin, has replaced the natural form in therapeutic usage such as treatment of dwarfism in children with growth hormone deficiency.Growth Hormone: A polypeptide that is secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Growth hormone, also known as somatotropin, stimulates mitosis, cell differentiation and cell growth. Species-specific growth hormones have been synthesized.Appetite Regulation: Physiologic mechanisms which regulate or control the appetite and food intake.Fasting: Abstaining from all food.Acylation: The addition of an organic acid radical into a molecule.Hunger: The desire for FOOD generated by a sensation arising from the lack of food in the STOMACH.Gastric Emptying: The evacuation of food from the stomach into the duodenum.Postprandial Period: The time frame after a meal or FOOD INTAKE.Receptors, G-Protein-Coupled: The largest family of cell surface receptors involved in SIGNAL TRANSDUCTION. They share a common structure and signal through HETEROTRIMERIC G-PROTEINS.Insulin: A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).Growth Hormone-Releasing Hormone: A peptide of 44 amino acids in most species that stimulates the release and synthesis of GROWTH HORMONE. GHRF (or GRF) is synthesized by neurons in the ARCUATE NUCLEUS of the HYPOTHALAMUS. After being released into the pituitary portal circulation, GHRF stimulates GH release by the SOMATOTROPHS in the PITUITARY GLAND.Feeding Behavior: Behavioral responses or sequences associated with eating including modes of feeding, rhythmic patterns of eating, and time intervals.Neuropeptide Y: A 36-amino acid peptide present in many organs and in many sympathetic noradrenergic neurons. It has vasoconstrictor and natriuretic activity and regulates local blood flow, glandular secretion, and smooth muscle activity. The peptide also stimulates feeding and drinking behavior and influences secretion of pituitary hormones.Satiety Response: Behavioral response associated with the achieving of gratification.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Energy Metabolism: The chemical reactions involved in the production and utilization of various forms of energy in cells.Body Weight: The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.Conservation of Energy Resources: Planned management, use, and preservation of energy resources.PubMed: A bibliographic database that includes MEDLINE as its primary subset. It is produced by the National Center for Biotechnology Information (NCBI), part of the NATIONAL LIBRARY OF MEDICINE. PubMed, which is searchable through NLM's Web site, also includes access to additional citations to selected life sciences journals not in MEDLINE, and links to other resources such as the full-text of articles at participating publishers' Web sites, NCBI's molecular biology databases, and PubMed Central.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.BooksPublishing: "The business or profession of the commercial production and issuance of literature" (Webster's 3d). It includes the publisher, publication processes, editing and editors. Production may be by conventional printing methods or by electronic publishing.MEDLINE: The premier bibliographic database of the NATIONAL LIBRARY OF MEDICINE. MEDLINE® (MEDLARS Online) is the primary subset of PUBMED and can be searched on NLM's Web site in PubMed or the NLM Gateway. MEDLINE references are indexed with MEDICAL SUBJECT HEADINGS (MeSH).Serial Publications: Publications in any medium issued in successive parts bearing numerical or chronological designations and intended to be continued indefinitely. (ALA Glossary of Library and Information Science, 1983, p203)Access to Information: Individual's rights to obtain and use information collected or generated by others.Journal Impact Factor: A quantitative measure of the frequency on average with which articles in a journal have been cited in a given period of time.Bibliometrics: The use of statistical methods in the analysis of a body of literature to reveal the historical development of subject fields and patterns of authorship, publication, and use. Formerly called statistical bibliography. (from The ALA Glossary of Library and Information Science, 1983)Peer Review, Research: The evaluation by experts of the quality and pertinence of research or research proposals of other experts in the same field. Peer review is used by editors in deciding which submissions warrant publication, by granting agencies to determine which proposals should be funded, and by academic institutions in tenure decisions.Receptors, Leptin: Cell surface receptors for obesity factor (LEPTIN), a hormone secreted by the WHITE ADIPOCYTES. Upon leptin-receptor interaction, the signal is mediated through the JAK2/STAT3 pathway to regulate food intake, energy balance and fat storage.Obsessive Hoarding: Persistent difficulty discarding or parting with possessions, regardless of the value of these possessions. Epidemiological studies suggest that hoarding occurs in 2-5% of the population and can lead to substantial distress and disability, as well as serious public health consequences.Antibodies: Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).Antibody Specificity: The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Antibodies, Viral: Immunoglobulins produced in response to VIRAL ANTIGENS.Dominance-Subordination: Relationship between individuals when one individual threatens or becomes aggressive and the other individual remains passive or attempts to escape.Anecdotes as Topic: Brief accounts or narratives of an incident or event.AnecdotesBehavior, Animal: The observable response an animal makes to any situation.Stress, Psychological: Stress wherein emotional factors predominate.Baseball: A competitive nine-member team sport including softball.Hobbies: Leisure activities engaged in for pleasure.Drugs, Investigational: Drugs which have received FDA approval for human testing but have yet to be approved for commercial marketing. This includes drugs used for treatment while they still are undergoing clinical trials (Treatment IND). The main heading includes drugs under investigation in foreign countries.Weight Lifting: A sport in which weights are lifted competitively or as an exercise.Estrogen Antagonists: Compounds which inhibit or antagonize the action or biosynthesis of estrogenic compounds.Athletes: Individuals who have developed skills, physical stamina and strength or participants in SPORTS or other physical activities.