Comparative metabolism of PGFM (13,14-dihydro-15-keto-PGF2α) in feces of felids

Comparison of tigers' fecal glucocorticoids level in two extreme habitats

Application of different antibodies and extraction methods results in a wide range of steroid metabolite concentrations obtained during noninvasive hormones monitoring. It makes regional comparisons of steroid concentration very difficult. We compared three methods for extraction of glucocorticoids metabolites in tiger feces to examine correct stress level in Bengal and Amur tigers in India and Russia respectively. The results obtained with three different extraction methods correlate with each other positively and significantly. The highest concentration of fecal glucocorticoids metabolites (FGCM) was found after the extraction of wet feces samples with 90% methanol. The level of FGCM was significantly higher in Bengal tigers in India than in Amur tigers in Russian Far East. The reasons might be related to tigers' density or anthropogenic pressure.

Use of urinary 13,14, dihydro-15-keto-prostaglandin F2α (PGFM) concentrations to diagnose pregnancy and predict parturition in the giant panda (Ailuropoda melanolecua)

Pregnancy determination is difficult in the giant panda (Ailuropoda melanolecua), representing a challenge for ex situ conservation efforts. Research in other species experiencing pseudopregnancy indicates that urinary/fecal concentrations of 13,14, dihydro-15-keto-prostaglandin F_2α (PGFM) can accurately determine pregnancy status. Our objective was to determine if urinary PGFM concentrations are associated with pregnancy status in the giant panda. Urinary PGFM concentrations were measured in female giant pandas (n = 4) throughout gestation (n = 6) and pseudopregnancy (n = 4) using a commercial enzyme immunoassay. Regardless of pregnancy status, PGFM excretion followed a predictable pattern: 1) baseline concentrations for 11–19 weeks following ovulation; 2) a modest, initial peak 14–36 days after the start of the secondary urinary progestagen rise; 3) a subsequent period of relatively low concentrations; and 4) a large, terminal peak at the end of the luteal phase. Pregnant profiles were distinguished by an earlier initial peak (P = 0.024), higher inter-peak concentrations (P < 0.001), and a larger terminal peak (P = 0.003) compared to pseudopregnancy profiles. Parturition occurred 23 to 25 days from the initial PGFM surge and within 24 hours of the start of the terminal increase. These pattern differences indicate that urinary PGFM monitoring can be used to predict pregnancy status and time parturition in the giant panda. Furthermore, this is the only species known to exhibit a significant PGFM increase during pseudopregnancy, suggesting a unique physiological mechanism for regulating the end of the luteal phase in the giant panda.

Non-Invasive Pregnancy Diagnosis in Big Cats using the PGFM (13,14-dihydro-15-keto-PGF2α) Assay

Non-invasive monitoring of hormones using feces has become a vital tool for reproductive management and reliable pregnancy diagnosis in big cats. Previous studies described the PGF_2α metabolite (PGFM) as an indicator of pregnancy in various feline species. The present study aimed to standardize pregnancy detection in big cats like the tiger (Panthera tigris), jaguar (Panthera onca) and lion (Panthera leo) using fecal samples. High-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LCMS) were performed to identify PGFM in feces. An EIA developed against 9α,11α-dihydroxy-15-oxo-prost-5-en-1-oic acid-BSA was used to assay PGFM in fecal samples of the Bengal tiger, Asiatic lion and jaguar. The PGFM levels increased after 9 weeks of pregnancy and remained elevated until parturition. All animals showed elevated levels of PGFM in the last trimester of pregnancy, thus making PGFM a reliable tool for pregnancy diagnosis during this period that can be useful in captive breeding programs in these species.