The mammalian melanocortin system has been established as a crucial regulatory component in an extraordinarily diverse number of physiological functions. In contrast, comparatively little is known about the avian melanocortin system: interest in the physiological role of alpha-MSH in birds has been limited by the fact that birds lack the intermediate lobe of the pituitary, the main source of circulating alpha-MSH in most vertebrates. Recently, however, the main avian melanocortin system genes, including POMC, AGRP, and all the melanocortin receptors, have been cloned and their physiological roles are the beginning to be elucidated. This review outlines our improved understanding of the avian melanocortin system, particularly in relation to two of the most widely studied physiological functions of the melanocortin system in mammals, the regulation of pigmentation and energy homeostasis. The data reviewed here indicate that the melanocortin system has been strongly conserved during vertebrate evolution and that alpha-MSH is produced locally in birds to act as an autocrine/paracrine hormone.
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http://dx.doi.org/10.1016/j.peptides.2004.11.039 | DOI Listing |
Curr Obes Rep
January 2025
Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
Purpose Of Review: Hyperphagia is a condition associated with rare obesity-related diseases, presenting as a pathologic, insatiable hunger accompanied by abnormal food-seeking behaviors. In October 2023, a group of researchers and clinicians with expert knowledge on hyperphagia convened at the annual ObesityWeek meeting to discuss the need for a unified definition of hyperphagia and key items necessary to improve the identification, assessment, and treatment of hyperphagia in patients with melanocortin 4 receptor (MC4R) pathway-associated diseases.
Recent Findings: The definition of hyperphagia proposed by this group is a pathologic, insatiable hunger accompanied by abnormal food-seeking behaviors.
Hum Mol Genet
January 2025
Department of Metabolism and Systems Science, University of Birmingham, Birmingham, B15 2TT, United Kingdom.
The melanocortin-4 receptor (MC4R) is a G protein-coupled receptor expressed at hypothalamic neurons that has an important role in appetite suppression and food intake. Mutations in MC4R are the most common cause of monogenic obesity and can affect multiple signaling pathways including Gs-cAMP, Gq, ERK1/2, β-arrestin recruitment, internalization and cell surface expression. The melanocortin-2 receptor accessory protein 2 (MRAP2), is a single-pass transmembrane protein that interacts with and regulates signaling by MC4R.
View Article and Find Full Text PDFGen Comp Endocrinol
January 2025
College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China. Electronic address:
The melanocortin-3 receptor (MC3R) was recognized for its critical role in energy metabolism and inflammatory responses in mammals; however, its functions in fish remain poorly understood. This study characterized the mc3r gene in goldfish, investigating its sequence, tissue distribution, and pharmacological responses. The coding sequence of goldfish mc3r was 975 bp, translating to a 325-amino-acid protein typical of G protein-coupled receptors, with notable conservation across cyprinids.
View Article and Find Full Text PDFNeuropharmacology
January 2025
Department of Neuroscience, University of Minnesota, Minneapolis, MN, 55455, USA.
Hypoactive sexual desire disorder (HSDD) is the most reported sexual dysfunction among premenopausal women worldwide. Bremelanotide, trade name Vyleesi, has been approved by the United States Food and Drug Administration to treat HSDD. However, despite approval, very little is known about its neurobiological mechanism of action.
View Article and Find Full Text PDFZhong Nan Da Xue Xue Bao Yi Xue Ban
July 2024
Department of Endocrinology &Metabolism, West China Hospital, Sichuan University, Chengdu 610041.
Cushing's disease is a rare endocrine disorder characterized by hypercortisolism. Chronic elevated cortisol levels can lead to dysfunction or complications in multiple organs of systems, including cardiovascular, glucose, and bone metabolism, severely impacting patients' quality of life and posing life-threatening risks. Surgery is the first-line treatment for Cushing's disease.
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