Blubber has been proposed as a possible alternative to blood in the assessment of endocrine physiology in marine mammals because it can be collected via remote biopsy, which removes some of the confounding variables and logistical constraints associated with blood collection. To date, few studies have directly assessed the relationships between circulating versus blubber steroid hormone profiles in marine mammals, and these studies have been limited to a small subset of steroid hormones, which collectively limit the current utility of blubber steroid hormone measurements. In this study, we used liquid-chromatography tandem-mass spectrometry (LC-MS/MS) to screen for 16 steroid hormones in matched blood and blubber samples from free-ranging common bottlenose dolphins (Tursiops truncatus). Seven steroid hormones were detected and quantified, including two progestogens, two androgens, and three corticosteroids. Using principal components analysis (PCA), we explored relationships between hormones in both matrices and three physiological states: sexual maturity, pregnancy, and acute stress response. Plasma and blubber testosterone and its precursors, 17-hydroxyprogesterone and androstenedione, loaded to the first principal component (PC1), and PC1 scores were higher in mature males. Plasma and blubber progesterone loaded to PC2, and pregnant/probable pregnant females had significantly higher PC2 scores. Pregnant females also had higher PC1 scores than other females, suggesting differences in androgen profiles between these groups. There was disagreement between plasma and blubber corticosteroid profiles, as indicated by their loading to different PCs; plasma corticosteroids loaded to PC3 and blubber corticosteroids to PC4. PC3 scores were significantly predicted by elapsed time to blood collection (i.e., time between initiating the capture process and blood collection), while elapsed time to blubber collection significantly predicted PC4 scores, indicating that corticosteroid profiles shift in both tissues during acute stress. Corticosteroid profiles were not related to demographic group, site-month, body mass index, water temperature, or time spent outside of the water on the processing boat. Overall, these results demonstrate that blubber steroid hormone profiles reflect changes in endocrine function that occur over broad temporal scales.

在海洋哺乳动物的内分泌生理学评估中，提出了一种代替血液的可能替代物，因为它可以通过远程活检来收集，从而消除了一些与血液收集有关的混杂变量和后勤限制。迄今为止，很少有研究直接评估海洋哺乳动物中循环与脂族类固醇激素谱之间的关系，并且这些研究仅限于一小部分类固醇激素，这总体上限制了脂族类固醇激素测量的当前效用。在这项研究中，我们使用液相色谱串联质谱（LC-MS / MS）从自由放宽的宽吻宽吻海豚（Tursiops truncatus）中筛选了匹配的血液和油脂样品中的16种类固醇激素。。检测并定量了7种类固醇激素，包括2种孕激素，2种雄激素和3种皮质类固醇。使用主成分分析（PCA），我们探索了两种基质中荷尔蒙与三种生理状态之间的关系：性成熟，怀孕和急性应激反应。血浆和脂肪族睾丸激素及其前体17-羟基孕酮和雄烯二酮负载在第一主要成分（PC1）上，并且PC1分数在成年男性中较高。血浆和润滑脂黄体酮负载在PC2上，怀孕/可能怀孕的女性的PC2评分明显更高。怀孕的女性也比其他女性具有更高的PC1分数，表明这些组之间雄激素谱存在差异。血浆和润滑脂皮质类固醇激素之间存在分歧，如它们加载到不同PC所表明的；血浆皮质类固醇加载到PC3，脂族皮质类固醇加载到PC4。通过采血时间（即开始捕获过程和采血之间的时间）可以显着预测PC3评分，而通过润滑脂收集的时间可以显着预测PC4评分，表明皮质类固醇激素分布在急性应激期间在两个组织中均发生变化。皮质类固醇激素谱与人群，地点月份，体重指数，水温或在加工船上在水外停留的时间无关。总体而言，这些结果表明，脂类固醇激素的概况反映了在广泛的时间范围内发生的内分泌功能的变化。通过采血时间（即开始捕获过程和采血之间的时间）可以显着预测PC3评分，而通过润滑脂收集的时间可以显着预测PC4评分，表明皮质类固醇激素分布在急性应激期间在两个组织中均发生变化。皮质类固醇激素谱与人群，地点月份，体重指数，水温或在加工船上在水外停留的时间无关。总体而言，这些结果表明，脂类固醇激素的概况反映了在广泛的时间范围内发生的内分泌功能的变化。通过采血时间（即开始捕获过程和采血之间的时间）可以显着预测PC3评分，而通过润滑脂收集的时间可以显着预测PC4评分，表明皮质类固醇激素分布在急性应激期间在两个组织中均发生变化。皮质类固醇激素谱与人群，地点月份，体重指数，水温或在加工船上在水外停留的时间无关。总体而言，这些结果表明，脂类固醇激素的概况反映了在广泛的时间范围内发生的内分泌功能的变化。提示在急性应激期间，皮质类固醇激素分布在两个组织中均发生了变化。皮质类固醇激素谱与人群，地点月份，体重指数，水温或在加工船上在水外停留的时间无关。总体而言，这些结果表明，脂类固醇激素的概况反映了在广泛的时间范围内发生的内分泌功能的变化。提示在急性应激期间，皮质类固醇激素分布在两个组织中均发生了变化。皮质类固醇激素谱与人群，地点月份，体重指数，水温或在加工船上在水外停留的时间无关。总体而言，这些结果表明，脂类固醇激素的概况反映了在广泛的时间范围内发生的内分泌功能的变化。