Plasma concentrations of progesterone, oestradiol, LH and 15-ketodihydro-PGF2 alpha in Norwegian semi-domestic reindeer (Rangifer tarandus tarandus) during their first reproductive season.
Blood samples were collected from eleven 1.5 year old female reindeer three times a week from September 1992 until February 1993 and daily in October and November 1992. Blood samples were collected every third hour for a period of three weeks from two females that showed regular oestrous cycles. Plasma progesterone, oestradiol, LH and 15-ketodihydro-PGF2 alpha were analysed to characterize variations in ovarian function. Reindeer are seasonally polyoestrous. Average duration of oestrous cycles was 19.4 days (range: 13-33 days). Short periods of high progesterone concentrations (4-8 days duration) occurred in five animals before the onset of regular oestrous cycles. The first regular cycle had a significantly longer luteal phase than did the following cycles. During luteolysis 15-ketodihydro-PGF2 alpha was released in a pulsatile pattern. Maximal oestradiol concentrations preceded preovulatory LH peaks by about 3 h in the two frequently sampled animals. The duration of LH surges was 12 and 15 h, respectively.
Ropstad
E
E
Norwegian College of Veterinary Medicine, Department of Reproduction and Forensic Medicine, Oslo, Norway.
Forsberg
M
M
Sire
J E
JE
Kindahl
H
H
Nilsen
T
T
Pedersen
O
O
Edqvist
L E
LE
D000818:Animals; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000097:blood; D004958:Estradiol / Q000097:blood; D004971:Estrus / Q000097:blood; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D008183:Luteal Phase; D007986:Luteinizing Hormone / Q000097:blood*; D011374:Progesterone / Q000097:blood; D012053:Reindeer / Q000097:blood*; D012741:Sexual Maturation / Q000502:physiology*; D013997:Time Factors
D012739:Gonadal Steroid Hormones; C008228:15-keto-13,14-dihydroprostaglandin F2alpha; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D015237:Dinoprost