Prolactin secretion and ovarian function in cycling and non-cycling African female elephants (Loxodonta africana)

Yuki Yamamoto, Tatsuya Yamamoto, Gen Watanabe, Natsuki Yuto, Megumi Keio, Etsuo Narushima, Masayuki Katayanagi, Risa Nakao, Syu Morikubo, Yuko Sakurai, Mikako Kaneko, Saroch Kaewmanee, Kazuyoshi Taya

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


Reproduction of captive elephants in zoos has shown a low fecundity and requires improvement. One of the reasons for low fecundity is ovarian dysfunction in many female elephants. To investigate whether prolactin has a correlation with ovarian function in female elephants, the serum concentrations of prolactin, progesterone and estradiol-17β in four African female elephants (one cycling female and three non-cycling female elephants) were measured. Cyclic patterns of prolactin and estradiol-17β were observed in the cycling female elephant, which tended to be high during the follicular phase and low during the luteal phase. On the other hand, a cyclic pattern of prolactin was not observed in the non-cycling female elephants. One of the three non-cycling females (Mako) had developed breasts and showed significantly higher average levels of prolactin than the other female elephants. These results suggested that high concentrations of circulating estradiol-17β during the follicular phase stimulated prolactin secretion. They also suggested that hyperprolactinemia in Mako was one of the causes of the developed mammary glands and ovarian dysfunction.

Original languageEnglish
Pages (from-to)845-852
Number of pages8
JournalJournal of Veterinary Medical Science
Issue number7
Publication statusPublished - Jul 2010
Externally publishedYes


  • African elephant
  • Estrous cycle
  • Hyperprolactinemia
  • Ovarian function
  • Prolactin

ASJC Scopus subject areas

  • veterinary(all)


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