Ramser Alison, Dridi Sami
Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA.
Cell and Molecular Biology Program, Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA.
Vet Sci. 2022 Mar 3;9(3):112. doi: 10.3390/vetsci9030112.
Originally named for its expression in the posterior hypothalamus in rats and after the Greek word for "appetite", hypocretin, or orexin, as it is known today, gained notoriety as a neuropeptide regulating feeding behavior, energy homeostasis, and sleep. Orexin has been proven to be involved in both central and peripheral control of neuroendocrine functions, energy balance, and metabolism. Since its discovery, its ability to increase appetite as well as regulate feeding behavior has been widely explored in mammalian food production animals such as cattle, pigs, and sheep. It is also linked to neurological disorders, leading to its intensive investigation in humans regarding narcolepsy, depression, and Alzheimer's disease. However, in non-mammalian species, research is limited. In the case of avian species, orexin has been shown to have no central effect on feed-intake, however it was found to be involved in muscle energy metabolism and hepatic lipogenesis. This review provides current knowledge and summarizes orexin's physiological roles in livestock and pinpoints the present lacuna to facilitate further investigations.
食欲素最初因在大鼠下丘脑后部表达而得名，其名称源于希腊语中表示“食欲”的词，如今被称为食欲素或增食因子，作为一种调节进食行为、能量平衡和睡眠的神经肽而声名远扬。食欲素已被证明参与神经内分泌功能、能量平衡和代谢的中枢及外周控制。自其被发现以来，它在牛、猪和羊等哺乳动物生产动物中增加食欲以及调节进食行为的能力已得到广泛研究。它还与神经系统疾病有关，这导致其在人类中针对发作性睡病、抑郁症和阿尔茨海默病进行了深入研究。然而，在非哺乳动物物种中，研究有限。就禽类而言，食欲素已被证明对采食量没有中枢作用，但发现它参与肌肉能量代谢和肝脏脂肪生成。本综述提供了当前的知识，并总结了食欲素在牲畜中的生理作用，指出了目前的空白，以促进进一步的研究。
