Nabi Ghulam, Robeck Todd R, Yujiang Hao, Tang Bin, Zheng Jinsong, Wang Kexiong, Wang Ding
The Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Conserv Physiol. 2021 May 11;9(1):coab034. doi: 10.1093/conphys/coab034. eCollection 2021.
Our understanding about how environmental and biological variables may influence circulating thyroid and adrenal hormones in free-ranging cetaceans is limited. As such, we used liquid chromatography-mass spectrometry to determine concentrations of circulating cortisol and thyroid hormones (THs; tT3, tT4) in 132 Yangtze finless porpoises (YFPs) located in Poyang Lake, (PL, = 92) and Tian-E-Zhou Oxbow reserve (TZO, = 40). For overall hormone comparisons, animals were partitioned by age [juvenile and adult (male and non-pregnant, non-lactating female)], sex, season (winter or spring) and geographical location. Geographically, during winter, circulating THs were significantly higher in the PL versus TZO population. Seasonally, within PL, THs were significantly higher in the winter versus spring season. Animals were further binned into groups as follows: juvenile male (JM) and juvenile female (JF), adult male (AM), non-pregnant adult female, pregnant female and non-pregnant lactating female. Intra-group comparisons between locations showed a significant increase in JM THs at PL. Significant increases in THs during winter compared to spring were detected between JM and JF groups. Mean comparisons of cortisol within and between locations for each group identified a significant increase for TZO AM versus TZO pregnant female and JM and JF. Seasonally, in PL, only JF has significantly higher cortisol in winter versus spring. Finally, we established reference values of THs and cortisol for YFPs in different geographical locations. These references are important baselines from which the effects of environmental and biological variables on THs and cortisol may be evaluated.
我们对于环境和生物变量如何影响自由放养的鲸类动物体内循环甲状腺激素和肾上腺激素的了解有限。因此，我们使用液相色谱-质谱法测定了位于鄱阳湖（PL，n = 92）和天鹅洲故道保护区（TZO，n = 40）的132头长江江豚（YFP）体内循环皮质醇和甲状腺激素（THs；总三碘甲状腺原氨酸、总甲状腺素）的浓度。为了进行整体激素比较，我们根据年龄[幼年和成年（雄性以及未怀孕、未哺乳的雌性）]、性别、季节（冬季或春季）和地理位置对动物进行了划分。在地理方面，冬季时，PL种群的循环THs显著高于TZO种群。在季节方面，在PL内，冬季的THs显著高于春季。动物进一步分为以下几组：幼年雄性（JM）和幼年雌性（JF）、成年雄性（AM）、未怀孕成年雌性、怀孕雌性和未怀孕泌乳雌性。不同地点组内比较显示，PL的JM的THs显著增加。在JM和JF组之间检测到冬季的THs相较于春季有显著增加。对每组不同地点内和不同地点间的皮质醇进行均值比较发现，TZO的AM相较于TZO的怀孕雌性以及JM和JF有显著增加。在季节方面，在PL，只有JF在冬季的皮质醇显著高于春季。最后，我们建立了不同地理位置的长江江豚THs和皮质醇的参考值。这些参考值是重要的基线，据此可以评估环境和生物变量对THs和皮质醇的影响。
