Guinn Makayla A, Elliott Justin Y, Wittmaack Christiana S, Sinclair Carrie, Abdulla Hussain A, Orbach Dara N
Texas A&M University-Corpus Christi, 6300 Ocean Drive, Corpus Christi, Texas 78412, United States.
Hydrosphere, 2034 Beacon Avenue, Monroe, North Caerolina 28110, United States.
ACS Omega. 2024 Oct 29;9(45):45068-45079. doi: 10.1021/acsomega.4c05466. eCollection 2024 Nov 12.
Bottlenose dolphins () inhabit environments with variable natural salinities and experience physiological imbalances from extreme salinity fluctuations. Low salinity exposure (≤10) disrupts osmoregulation and increases the production of steroid hormones aldosterone (electrolyte balance) and cortisol (stress response). The effect(s) of high salinity exposure (>35) on steroid hormone production in bottlenose dolphins has not previously been assessed. We measured stress hormones (aldosterone, corticosterone, cortisol, and cortisone) and reproductive hormones (progesterone and testosterone) in three stocks of free-ranging bottlenose dolphins inhabiting different natural salinities across the Gulf of Mexico (0-30, 22-35, 36+). Hormones were extracted from the blubber of 82 remotely biopsied dolphins and quantified using ultraperformance liquid chromatography coupled with Orbitrap Fusion mass spectrometry. A positive correlation was found between cortisol (10.38 ± 0.8 ng/g, = 13) and salinity ( = 0.62). Aldosterone (58.9 ± 17.2 ng/g, = 5) was quantified in dolphin blubber for the first time and was detected across the salinity gradient but was not significantly related to salinity levels. Concentrations of testosterone were seasonally variable. This study enhances our understanding of how climate changes and extensive anthropogenic stressors challenge homeostasis in a marine bioindicator species.
宽吻海豚（）栖息于自然盐度多变的环境中，并因极端盐度波动而出现生理失衡。低盐度暴露（≤10）会扰乱渗透调节，并增加类固醇激素醛固酮（电解质平衡）和皮质醇（应激反应）的产生。此前尚未评估高盐度暴露（>35）对宽吻海豚类固醇激素产生的影响。我们测量了墨西哥湾不同自然盐度区域（0 - 30、22 - 35、36+）的三群自由放养宽吻海豚的应激激素（醛固酮、皮质酮、皮质醇和可的松）和生殖激素（孕酮和睾酮）。从82只经远程活检的海豚的鲸脂中提取激素，并使用超高效液相色谱与Orbitrap Fusion质谱联用进行定量分析。发现皮质醇（10.38 ± 0.8 ng/g， = 13）与盐度（ = 0.62）之间存在正相关。醛固酮（58.9 ± 17.2 ng/g， = 5）首次在海豚鲸脂中被定量，且在整个盐度梯度中均被检测到，但与盐度水平无显著相关性。睾酮浓度存在季节性变化。这项研究增进了我们对气候变化和广泛的人为压力源如何挑战一种海洋生物指示物种体内稳态的理解。
