TY - JOUR
T1 - Prolonged luteal lifespan and pseudopregnancy in Asian elephants (Elephas maximus)
AU - Lueders, Imke
AU - Niemuller, Cheryl
AU - Steinmetz, Hanspeter W.
AU - Bouts, Tim
AU - Gray, Charlie
AU - Knauf-Witzens, Tobias
AU - Taya, Kazuyoshi
AU - Watanabe, Gen
AU - Yamamoto, Yuki
AU - Oerke, Ann Kathrin
N1 - Funding Information:
We express our gratitude to Dr. A. F. Parlow and the NationalInstitute of Diabetes and Digestive and Kidney Diseases (Torrance, CA, U.S.A.) for providing PRL RIA materials. We thank the Japan Society for the Promotion of Science (JSPS) for their support of this research which allowed sample analysis in Tokyo, Japan for prolactin (grant # PE 11016). We thank Prof. W.R. Allen for valuable input.
Funding Information:
We express our gratitude to Dr. A. F. Parlow and the NationalInstitute of Diabetes and Digestive and Kidney Diseases (Torrance, CA, U.S.A.) for providing PRL RIA materials. We thank the Japan Society for the Promotion of Science (JSPS) for their support of this research which allowed sample analysis in Tokyo, Japan for prolactin (grant # PE 11016 ). We thank Prof. W.R. Allen for valuable input.
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/10
Y1 - 2018/10
N2 - Pseudopregnancy is a physiological occurrence in mammals which have copulation induced ovulation, but is rarely described in spontaneous ovulating species. In this study, three cases of prolonged luteal lifespan are reported in non-pregnant Asian elephants (Elephas maximus). Case 1 was a 25-year-old female that had produced three calves previously; Case 2 was a nulliparous and 32-year-old at the start of the pseudopregnancy episode; and Case 3 occurred in a 49-year-old nulliparous elephant. Serum progesterone metabolite concentrations remained elevated for 10 months in Case 1. Urinary progestagens were high for >16 months in Case 2 and for five months in Case 3. In Case 1, multiple persistent corpora lutea were visualized monthly by ultrasonography. In all three cases, uterine leiomyoma were present and progestagen concentrations decreased spontaneously. In Case 1, the elephant became pregnant 3 years later, whilst with Case 2, the female resumed estrous cycling normally, and for the Case 3 female, there was continuation with another prolonged luteal phase before ovarian function was purposely suppressed. These examples indicate that persistently elevated progestagen concentrations may not always be indicative of pregnancy in elephants. The reasons for prolonged luteal lifespan are not understood, although serum prolactin concentrations quantified in the Case 1 female were elevated compared to values from previous reports and two other herd mates. Furthermore, all three elephants had varying degrees of uterine pathologies. It is believed that the resulting damage to the endometrium may have led to a reaction similar to implantation, which includes prolactin secretion. Prolactin may exert luteotropic properties and is thought to initiate luteal rescue during pregnancy in elephants.
AB - Pseudopregnancy is a physiological occurrence in mammals which have copulation induced ovulation, but is rarely described in spontaneous ovulating species. In this study, three cases of prolonged luteal lifespan are reported in non-pregnant Asian elephants (Elephas maximus). Case 1 was a 25-year-old female that had produced three calves previously; Case 2 was a nulliparous and 32-year-old at the start of the pseudopregnancy episode; and Case 3 occurred in a 49-year-old nulliparous elephant. Serum progesterone metabolite concentrations remained elevated for 10 months in Case 1. Urinary progestagens were high for >16 months in Case 2 and for five months in Case 3. In Case 1, multiple persistent corpora lutea were visualized monthly by ultrasonography. In all three cases, uterine leiomyoma were present and progestagen concentrations decreased spontaneously. In Case 1, the elephant became pregnant 3 years later, whilst with Case 2, the female resumed estrous cycling normally, and for the Case 3 female, there was continuation with another prolonged luteal phase before ovarian function was purposely suppressed. These examples indicate that persistently elevated progestagen concentrations may not always be indicative of pregnancy in elephants. The reasons for prolonged luteal lifespan are not understood, although serum prolactin concentrations quantified in the Case 1 female were elevated compared to values from previous reports and two other herd mates. Furthermore, all three elephants had varying degrees of uterine pathologies. It is believed that the resulting damage to the endometrium may have led to a reaction similar to implantation, which includes prolactin secretion. Prolactin may exert luteotropic properties and is thought to initiate luteal rescue during pregnancy in elephants.
KW - Corpus luteum
KW - Elephant
KW - Leiomyoma
KW - Pregnancy
KW - Progesterone
KW - Prolactin
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U2 - 10.1016/j.anireprosci.2018.08.008
DO - 10.1016/j.anireprosci.2018.08.008
M3 - Article
C2 - 30122269
AN - SCOPUS:85051704725
VL - 197
SP - 58
EP - 66
JO - Animal Reproduction Science
JF - Animal Reproduction Science
SN - 0378-4320
ER -