Kulczykowska Ewa, Kalamarz-Kubiak Hanna, Gozdowska Magdalena, Sokołowska Ewa
Department of Genetics and Marine Biotechnology, Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55 Str., 81-712 Sopot, Poland.
Department of Genetics and Marine Biotechnology, Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55 Str., 81-712 Sopot, Poland.
Comp Biochem Physiol A Mol Integr Physiol. 2018 Apr;218:1-7. doi: 10.1016/j.cbpa.2018.01.003. Epub 2018 Feb 2.
The stress hormone cortisol, together with antioxidants, melatonin (Mel) and its biologically active metabolites, 5-methoxykynuramines, including AFMK, set up a local stress response system in mammalian skin. Our in vitro study of the European flounder (Platichthys flesus) was designed to examine whether Mel and AFMK would respond to cortisol while a glucocorticoid is added to the incubation medium. The concentrations of cortisol in the incubation medium mimic plasma cortisol levels seen in fish exposed to different types of stresses such as handling, confinement, high density, food-deprivation or air-exposure. We measured Mel and AFMK in skin explants and culture media using high-performance liquid chromatography (HPLC) with fluorescence detection. We also analysed melanosome response (dispersion/aggregation) in the explants subjected to the different treatments. Cortisol stimulated the release of Mel and AFMK from skin explants in a dose-dependent manner. Melanosome dispersion and a darkening of the skin explants were observed after incubation with cortisol. This study is the first to demonstrate the interrelationship between cortisol and Mel/AFMK in fish skin. Our data strongly suggest that the cutaneous stress response system (CSRS) is present in fish. The question remains whether Mel, AFMK or cortisol are synthetized locally in fish skin and/or transported by the bloodstream. The presence of the CSRS should be taken into account during elaboration of new indicators of fish welfare both in aquaculture and in the wild.
应激激素皮质醇与抗氧化剂、褪黑素（Mel）及其生物活性代谢产物5-甲氧基犬尿胺（包括AFMK）共同在哺乳动物皮肤中建立了一个局部应激反应系统。我们对欧洲比目鱼（Platichthys flesus）进行的体外研究旨在检验在向孵育培养基中添加糖皮质激素时，Mel和AFMK是否会对应激激素皮质醇产生反应。孵育培养基中皮质醇的浓度模拟了鱼类在受到不同类型应激（如处理、限制、高密度、食物剥夺或暴露于空气中）时血浆中的皮质醇水平。我们使用带荧光检测的高效液相色谱法（HPLC）测量皮肤外植体和培养基中的Mel和AFMK。我们还分析了接受不同处理的外植体中的黑素体反应（分散/聚集）。皮质醇以剂量依赖的方式刺激皮肤外植体释放Mel和AFMK。用皮质醇孵育后，观察到黑素体分散和皮肤外植体变黑。这项研究首次证明了鱼类皮肤中皮质醇与Mel/AFMK之间的相互关系。我们的数据有力地表明鱼类中存在皮肤应激反应系统（CSRS）。问题仍然是Mel、AFMK或皮质醇是否在鱼类皮肤中局部合成和/或通过血液循环运输。在制定水产养殖和野生环境中鱼类福利的新指标时，应考虑CSRS的存在。
