Changes of plasma concentrations of steroid hormones, prostaglandin F2 alpha-metabolite and pregnant mare serum gonadotropin during pregnancy in thoroughbred mares.
Plasma concentrations of estrogens, gestagens, cortisol (F), 13, 14-dihydro, 15-keto PGF2 alpha (PGFM) and pregnant mare serum gonadotropin (PMSG) in 10 Thoroughbred mares were measured for a 11-month pregnancy period. Estrone (E1) and estradiol-17 beta (E2) levels gradually increased as the pregnancy advanced, showing a peak around Month 8 and decreased thereafter. Progesterone (P) levels increased on Months 3 and 11, and 17 alpha-OH-progesterone (17 alpha-OHP) levels peaked on Month 3, whereas 20 alpha-OH-progesterone (20 alpha-OHP) levels increased sharply after Month 6. PGFM indicated peaks on Months 2 and 11. F and PMSG levels peaked on Months 2 and 3. From factor analysis, Month, E1, E2 and 20 alpha-OHP were discriminated as Factor 1, increasing with the progress of pregnancy, PMSG, 17 alpha-OHP and P as Factor 2, showing a relation with the secondary corpus luteum, and PGFM and F as Factor 3, affecting PGFM change on Month 2 by F. P also related to both Factors 1 and 3, showing an inverse relation against PGFM. In conclusion E1, E2 and 20 alpha-OHP contained in Factor 1 were suggested to be important especially as parameters of placental function after Month 6.
Tsumagari
S
S
Department of Veterinary Obstetrics and Gynecology, College of Agriculture and Veterinary Medicine, Nihon University, Kanagawa, Japan.
Higashino
T
T
Takagi
K
K
Ohba
S
S
Satoh
S
S
Takeishi
M
M
D000818:Animals; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000097:blood; D004958:Estradiol / Q000097:blood; D004970:Estrone / Q000097:blood; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006064:Gonadotropins, Equine / Q000097:blood*; D006736:Horses / Q000097:blood*; D006854:Hydrocortisone / Q000097:blood; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000097:blood*; D011374:Progesterone / Q000097:blood
D012739:Gonadal Steroid Hormones; D006064:Gonadotropins, Equine; C008228:15-keto-13,14-dihydroprostaglandin F2alpha; D004970:Estrone; D011374:Progesterone; D004958:Estradiol; D015237:Dinoprost; D006854:Hydrocortisone