Liquid chromatography tandem mass spectrometry for the quantitation of steroid hormone profiles in blubber from stranded humpback whales (Megaptera novaeangliae)
Greta Dalle Luche, Susan Bengston Nash, John Kucklick, Fletcher M. Mingramm, Ashley Russell
Marine mammal blubber is known to have quantifiable concentrations of steroid hormones and is increasingly chosen as a matrix for the detection of these reproductive and stress biomarkers. Steroid hormones act through complex cascades, often in concert, yet studies conducted on cetaceans have rarely measured more than two steroids simultaneously. Due to the role of steroid hormones in multiple physiological processes, and variability in concentration among individuals, data on single compounds are often difficult to interpret. Here a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the simultaneous analyses of multiple steroid hormones in cetacean blubber is validated and applied to 10 stranded humpback whales (Megaptera novaeangliae). Eleven endogenous steroid compounds were detected at biologically relevant concentrations and quantified. Repeatability ranged from 4.32 % to 17.4 % relative standard deviation. Measurement accuracy was calculated relative to a fortified sample as between 83.8 % and 112 %. Cortisol and progesterone were compared to results obtained through and enzyme immunoassay in samples from five individuals. The two methods were found to be comparable (95 %), but only in a restricted concentration range (cortisol < 14.1 ng/g, progesterone < 9.91 ng/g). Estrone concentrations were quantified in female and male whales of different age groups. In contrast to previous studies, estradiol was undetectable in the majority of the samples using LC-MS/MS. Progesterone, cortisol, and cortisone were the dominant hormones detected in stranded whales, indicating a possible role of all of these hormones during stress response. As outer blubber tissues are routinely collected via non- lethal remote biopsy in cetacean monitoring and research programs, this methodology could have important diagnostic applications in the monitoring of live whales of this species.
Dalle Luche, G.
, Bengston Nash, S.
, Kucklick, J.
, Mingramm, F.
and Russell, A.
Liquid chromatography tandem mass spectrometry for the quantitation of steroid hormone profiles in blubber from stranded humpback whales (Megaptera novaeangliae), Conservation Physiology
(Accessed December 2, 2023)