A proposed technique for quantifying muscle progesterone content in minke whales ( Balaenoptera acutorostrata )

• Published in: Canadian Journal of Zoology
• Main Authors: Yoshioka, Motoi, Okumura, Takuji, Aida, Katsumi, Fujise, Yoshihiro
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1994
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Balaenoptera acutorostrata
• Online Access: http://dx.doi.org/10.1139/z94-051; http://www.nrcresearchpress.com/doi/pdf/10.1139/z94-051

We have developed a new technique for the quantitative extraction of progesterone from very small pieces of muscle tissue of minke whales (Balaenoptera acutorostrata) post mortem. Ethanol extracts of approximately 0.5 g of tissue contained, on average, 15.3 ng/g progesterone in the case of pregnant females (SD = 12.7, n = 9) and 0.32 ng/g progesterone in the case of immature females (SD = 0.03, n = 9). Differences in muscle progesterone levels between females in the two reproductive states were significant, as has been previously reported also for serum levels. Our technique is expected to be applicable in the near future to the determination of the presence or absence of the corpus luteum in the ovaries and the reproductive status of free-ranging female whales, provided that sampling techniques for muscle biopsies are developed.