Abstract

The role of circulatory glucocorticoids along with melatonin in the regulation of lung-associated cell-mediated immunity has never been explored in any tropical bird. This could be interesting because glucocorticoids are immunosuppressive while melatonin is immunostimulatory in nature. In our present study, we report the localization and expression of the glucocorticoid and melatonin receptors and the effect of melatonin on dexamethasone-induced suppression of lung-associated and general immunity in the jungle bush quail Perdicula asiatica. The birds were treated with melatonin and dexamethasone at dose of 25µg/100g B.wt./day and 30µg/100g B.wt./day, respectively, for twenty eight days. At the end of the experiment, the birds were sacrificed and lung tissues and blood samples were collected for histology and morphometric analysis of lymphoid tissue (BALT and non-BALT nodules), total leukocyte count (TLC), lymphocyte count (LC), percent stimulation ratio of isolated lung lymphocytes (% SR), immunohistochemistry, western blot analysis and hormonal assay. Dexamethasone injection reduced the immune status in terms of the size of BALT and non-BALT nodules, TLC, LC and % SR, upregulated expression of the glucocorticoid receptor (GR) and downregulated expression of melatonin receptor types Mel_1a and Mel_1b. Melatonin administration increased the above immune parameters and upregulated expression of melatonin receptor types Mel_1a and Mel_1b while downregulating GR. Our results suggest the existence of the trade-off relationship between melatonin and corticosterone, which might be responsible for the regulation of lung-associated cell-mediated immunity under stress conditions via their receptors in the lung of the jungle bush quail Perdicula asiatica.

中文翻译：

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褪黑激素和糖皮质激素受体表达与丛林布什鹌鹑Perdicula asiatica中的肺相关细胞介导的免疫变化：褪黑激素和地塞米松之间的权衡。

摘要

从未在任何热带鸟类中探索过循环糖皮质激素与褪黑激素在调节肺相关细胞介导的免疫中的作用。这可能很有趣，因为糖皮质激素具有免疫抑制作用，而褪黑激素本质上具有免疫刺激作用。在我们目前的研究中，我们报告了糖皮质激素和褪黑激素受体的定位和表达以及褪黑素对地塞米松诱导的丛林灌木鹌鹑鹌鹑Perdicula asiatica抑制的肺相关免疫和一般免疫的影响。。用褪黑激素和地塞米松分别以25μg/ 100g B.wt./天和30μg/ 100g B.wt./天的剂量处理禽类，持续28天。实验结束时，处死禽类，收集肺组织和血样，用于淋巴样组织（BALT和非BALT结节）的组织学和形态分析，总白细胞计数（TLC），淋巴细胞计数（LC），百分比分离的肺淋巴细胞的刺激比率（％SR），免疫组织化学，蛋白质印迹分析和激素测定。地塞米松注射液可降低BALT和非BALT结节的大小，TLC，LC和SR％，糖皮质激素受体（GR）的表达上调以及褪黑激素受体Mel _1a和Mel _1b的表达下调的免疫状态。褪黑激素的施用增加了上述免疫参数，并上调了褪黑激素受体类型的Mel _1a和Mel _1b的表达。我们的研究结果表明褪黑激素和皮质酮之间存在折衷关系，这可能是应激条件下通过丛林灌木鹌鹑鹌鹑Perdicula asiatica的肺中受体调节肺相关细胞介导的免疫的原因。