Identification of progesterone and 5α-dihydroprogesterone (5α-DHP) in zebras by two-dimensional high-performance liquid chromatography and their dependence on the state of reproduction
✍ Scribed by Franz Klima; Marlies Rohleder; Martin Dehnhard; Heinrich H.D. Meyer
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 108 KB
- Volume
- 18
- Category
- Article
- ISSN
- 0733-3188
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✦ Synopsis
Because of its low levels in late pregnancy, the relationship of progesterone to pregnancy maintenance in Equidae is not obvious. This study investigated the levels of progesterone (4-pregnane-3,20-dione; P4) and 5α-dihydroprogesterone (5α-DHP) during pregnancy in zebras in relation to reproductive state. Blood samples from female zebras (Equus burchelli, E. zebra hartmannae, E. grevyi) were taken at Dvur Kralove Zoo. Progesterone and 5α-DHP were separated by high-performance liquid chromatography techniques and detected by cross-reacting antibodies. Identification of progestins was achieved by comparing the identity of peaks of the samples with a standard. In E. z. hartmannae progesterone, values reached 50 ng/mL at the beginning of pregnancy and dropped to levels below 1 ng/mL during the second half of pregnancy. In contrast, 5α-DHP increased up to 123 and 183 ng/mL during late pregnancy in E. z. hartmannae and E. burchelli, respectively. In E. grevyi, 5α-DHP levels of 368 ng/mL were obtained during pregnancy, whereas progesterone values were similar in pregnant and non-pregnant individuals. These marked differences in the course of progesterone and 5α-DHP levels point to the importance of 5α-DHP for pregnancy maintenance in zebras.