Department of Physiology, University of Turku, Turku, Finland.
Acta Physiol (Oxf). 2010 Mar;198(3):349-54. doi: 10.1111/j.1748-1716.2009.02006.x. Epub 2009 May 20.
Orexins (OX), OX-A and OX-B, were initially identified as hypothalamic neuropeptides primarily involved in the control of food intake and states of arousal. Thereafter, orexins have been substantiated as putative pleiotropic regulators of a wide diversity of biological systems, including different neuroendocrine axes. Among the latter, compelling experimental evidence has recently been documented that orexins, mainly OX-A, may act at different levels of the hypothalamic-pituitary-gonadal (HPG) axis to modulate reproductive function. These actions are likely to include regulatory effects on the hypothalamic centres governing the HPG axis, as well as direct actions at the gonadal level. We review herein the experimental evidence, gathered in recent years, supporting a reproductive 'facet' of orexins, with special emphasis on our current knowledge of their patterns of expression and potential functional roles in the testis. Overall, the available data strongly suggest that, by acting at different levels of the HPG axis, orexins may operate as putative neuroendocrine and autocrine/paracrine regulators of gonadal function.
食欲素（OX）、OX-A 和 OX-B 最初被确定为下丘脑神经肽，主要参与食物摄入和觉醒状态的控制。此后，食欲素被证实为广泛生物系统的潜在多效调节剂，包括不同的神经内分泌轴。在后者中，最近有令人信服的实验证据表明，食欲素（主要是 OX-A）可能在下丘脑-垂体-性腺（HPG）轴的不同水平上发挥作用，调节生殖功能。这些作用可能包括对调节 HPG 轴的下丘脑中枢的调节作用，以及在性腺水平上的直接作用。我们在此综述了近年来收集的支持食欲素具有生殖“方面”的实验证据，特别强调了我们目前对其在睾丸中的表达模式和潜在功能作用的认识。总的来说，现有数据强烈表明，通过在 HPG 轴的不同水平上发挥作用，食欲素可能作为神经内分泌和自分泌/旁分泌调节性腺功能的假定调节剂。
