Moore C B, Siopes T D
Department of Poultry Science, North Carolina State University, Raleigh, NC 27695-7608, USA.
Gen Comp Endocrinol. 2002 Nov;129(2):122-6. doi: 10.1016/s0016-6480(02)00516-6.
In recent years, it has been determined that melatonin has important immunostimulatory properties in mammalian and avian species. Typically, this immunoenhancement has only been examined in immunosuppressed animals. The effect of melatonin on normal (unsuppressed) immune systems is yet to be evaluated in avian species. An experiment was performed to determine if transient and/or continuous melatonin treatments could enhance immune functions in Japanese quail without prior immunosuppression. All quail were kept on a short photoperiod (8:16LD) throughout the study. In this experiment, 50.0 microg/ml melatonin was provided ad libitum to adult Japanese quail in the drinking water either continuously or for 3h per day. Control birds received diluent continuously throughout the experiment. Both the cellular and humoral immune responses were determined immediately after 3 weeks treatment. A cutaneous basophil hypersensitivity reaction to phytohemagglutinin (PHA-P) was measured to evaluate the cellular immune response. To evaluate the humoral immune response, primary antibody titers were calculated 7 days post-intravenous injection with a Chukar red blood cell (CRBC) suspension. The cellular and humoral immune responses were significantly elevated in the transient (3h) and continuous (24h) melatonin treatment groups as compared to the control group (0 h). As compared to the control group, the cellular immune response was increased 25% and 38% for the 3 and 24h melatonin treatments, respectively. The humoral immune response was increased 26% and 32% for the 3 and 24h melatonin treatments, respectively. Furthermore, continuous (24h) melatonin availability significantly increased the cellular, but not humoral immune responses as compared to the transient (3h) group, given melatonin for 3h prior to the scotophase (13:00-16:00 h). From these data, it was clear that transient and continuous administration of melatonin increased the cellular and humoral immune responses of Japanese quail without prior immunosuppression. These data suggest that the immunoenhancing effect of melatonin is not limited to reconstitution of weakened immune systems, but can be observed in normal, immunologically unsuppressed birds.
近年来，已确定褪黑素在哺乳动物和鸟类中具有重要的免疫刺激特性。通常，这种免疫增强作用仅在免疫抑制动物中进行过研究。褪黑素对正常（未受抑制）免疫系统的影响尚未在鸟类中进行评估。进行了一项实验，以确定短暂和/或持续的褪黑素处理是否可以在未预先免疫抑制的日本鹌鹑中增强免疫功能。在整个研究过程中，所有鹌鹑都处于短光照周期（8:16LD）。在本实验中，以50.0微克/毫升的褪黑素持续或每天3小时随意提供给成年日本鹌鹑的饮用水中。对照鸟在整个实验过程中持续接受稀释剂。在处理3周后立即测定细胞免疫和体液免疫反应。测量对植物血凝素（PHA-P）的皮肤嗜碱性粒细胞超敏反应以评估细胞免疫反应。为了评估体液免疫反应，在静脉注射石鸡红细胞（CRBC）悬液7天后计算初次抗体滴度。与对照组（0小时）相比，短暂（3小时）和持续（24小时）褪黑素处理组的细胞免疫和体液免疫反应均显著升高。与对照组相比，3小时和24小时褪黑素处理的细胞免疫反应分别增加了25%和38%。3小时和24小时褪黑素处理的体液免疫反应分别增加了26%和32%。此外，与短暂（3小时）组相比，在暗期（13:00-16:00小时）前3小时给予褪黑素的持续（24小时）褪黑素供应显著增加了细胞免疫反应，但未增加体液免疫反应。从这些数据可以清楚地看出，在未预先免疫抑制的情况下，短暂和持续给予褪黑素可增加日本鹌鹑的细胞免疫和体液免疫反应。这些数据表明，褪黑素的免疫增强作用不仅限于重建减弱的免疫系统，而且在正常的、未受免疫抑制的鸟类中也可以观察到。
