Prolactin secretion and ovarian function in cycling and non-cycling African female elephants (Loxodonta africana).
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-17beta in four African female elephants (one cycling female and three non-cycling female elephants) were measured. Cyclic patterns of prolactin and estradiol-17beta 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-17beta 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.
Yamamoto
Yuki
Y
Department of Basic Veterinary Science, Gifu University, Gifu, Japan.
Yamamoto
Tatsuya
T
Watanabe
Gen
G
Yuto
Natsuki
N
Keio
Megumi
M
Narushima
Etsuo
E
Katayanagi
Masayuki
M
Nakao
Risa
R
Morikubo
Syu
S
Sakurai
Yuko
Y
Kaneko
Mikako
M
Kaewmanee
Saroch
S
Taya
Kazuyoshi
K
D000818:Animals; D004606:Elephants / Q000502:physiology*; D004958:Estradiol / Q000097:blood; D030762:Estrous Cycle / Q000097:blood / Q000502:physiology; D005260:Female; D008321:Mammary Glands, Animal / Q000033:anatomy & histology / Q000502:physiology; D010053:Ovary / Q000502:physiology*; D011374:Progesterone / Q000097:blood; D011388:Prolactin / Q000097:blood / Q000378:metabolism*; D011863:Radioimmunoassay; D012756:Sheep
D011374:Progesterone; D004958:Estradiol; D011388:Prolactin