Cyrino João Cunha, de Figueiredo Aymam Cobo, Córdoba-Moreno Marlina Olyissa, Gomes Fernando Ribeiro, Titon Stefanny Christie Monteiro
Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo CEP 05508-090, São Paulo, Brasil.
Integr Comp Biol. 2022 Dec 30;62(6):1606-1617. doi: 10.1093/icb/icac028.
Pathogen-associated molecular patterns modulate melatonin (MEL) production in the pineal and extra-pineal sites and corticosterone (CORT) synthesis in the adrenal/interrenal and other tissues. Both MEL and CORT play essential and complex immunomodulatory roles, controlling the inflammatory response. Given that most of what we know about these interactions is derived from mammalian studies, discovering how MEL and CORT are modulated following an immune challenge in anurans would increase understanding of how conserved these immune-endocrine interactions are in vertebrates. Herein, we investigated the modulation of MEL and CORT in plasma vs. local tissues of toads (Rhinella icterica) in response to an immune challenge with lipopolysaccharide (LPS; 2 mg/kg) at day and night. Blood samples were taken 2 hours after injection (noon and midnight), and individuals were killed for tissue collection (bone marrow, lungs, liver, and intestine). MEL and CORT were determined in plasma and tissue homogenates. LPS treatment increased MEL concentration in bone marrow during the day. Intestine MEL levels were higher at night than during the day, particularly in LPS-injected toads. Bone marrow and lungs showed the highest MEL levels among tissues. Plasma MEL levels were not affected by either the treatment or the phase. Plasma CORT levels increased in LPS-treated individuals, with an accentuated increase at night. Otherwise, CORT concentration in the tissues was not affected by LPS exposure. Modulation of MEL levels in bone marrow suggests this tissue may participate in the toad's inflammatory response assembly. Moreover, MEL and CORT levels were different in tissues, pointing to an independent modulation of hormonal concentration. Our results suggest an important role of immune challenge in modulating MEL and CORT, bringing essential insights into the hormone-immune interactions during anuran's inflammatory response.
病原体相关分子模式可调节松果体和松果体外部位的褪黑素（MEL）生成，以及肾上腺/肾间组织和其他组织中的皮质酮（CORT）合成。MEL和CORT均发挥着重要且复杂的免疫调节作用，控制着炎症反应。鉴于我们目前对这些相互作用的了解大多来自哺乳动物研究，探究无尾两栖类动物在免疫刺激后MEL和CORT是如何被调节的，将有助于增进我们对脊椎动物中这些免疫 - 内分泌相互作用保守程度的理解。在此，我们研究了蟾蜍（Rhinella icterica）在白天和黑夜接受脂多糖（LPS；2 mg/kg）免疫刺激后，血浆和局部组织中MEL和CORT的调节情况。注射后2小时（中午和午夜）采集血样，并处死个体以收集组织（骨髓、肺、肝和肠）。测定血浆和组织匀浆中的MEL和CORT。LPS处理使白天骨髓中的MEL浓度升高。肠道MEL水平在夜间高于白天，尤其是在注射LPS的蟾蜍中。骨髓和肺在各组织中显示出最高的MEL水平。血浆MEL水平不受处理或时段的影响。LPS处理的个体血浆CORT水平升高，夜间升高更为明显。否则，组织中的CORT浓度不受LPS暴露的影响。骨髓中MEL水平的调节表明该组织可能参与蟾蜍炎症反应的组装。此外，各组织中MEL和CORT水平不同，表明激素浓度存在独立调节。我们的结果表明免疫刺激在调节MEL和CORT方面具有重要作用，为无尾两栖类动物炎症反应期间的激素 - 免疫相互作用提供了重要见解。
