Plasma steroid profiles following follicle-stimulating hormone or equine chorionic gonadotropin injection in cows chronically treated with gonadotropin-releasing hormone agonist.
Plasma steroid profiles following follicle-stimulating hormone (FSH) or equine chorionic gonadotropin (eCG) injection were studied in chronically gonadotropin releasing hormone agonist (GnRH-A)-treated cows. Follicular development and irINH secretion were stimulated by FSH or eCG injection. The plasma concentrations of estradiol-17 beta (E(2)) and testosterone (T) were markedly increased following eCG injection. However, significant increases of the plasma E(2) and T concentrations were not detected in FSH-treated cows. Ovulation of developed follicles were depended on the hCG injection in both groups. These results show: 1) Follicular response to an exogenous gonadotropin is still remained, 2) Ovulation of developed follicles is induced by hCG injection and 3) FSH and eCG cause disparate plasma steroid profiles, under the influence of repeated GnRH-A treatment.
Takahashi
Toru
T
National Institute of Agrobiological Sciences, Kukizaki, Ibaraki, Japan.
Hirako
Makoto
M
Patel
Osman V
OV
Shimizu
Manabu
M
Hasegawa
Yoshihisa
Y
Domeki
Ikuo
I
Hashizume
Kazuyoshi
K
D000818:Animals; D002417:Cattle / Q000097:blood* / Q000502:physiology; D006063:Chorionic Gonadotropin / Q000008:administration & dosage; D015237:Dinoprost / Q000008:administration & dosage; D004958:Estradiol / Q000097:blood; D005260:Female; D005300:Fertility Agents, Female / Q000819:agonists*; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists*; D006064:Gonadotropins, Equine / Q000494:pharmacology*; D007265:Inhibins / Q000097:blood; D006080:Ovarian Follicle / Q000187:drug effects* / Q000378:metabolism; D010062:Ovulation Induction / Q000379:methods / Q000662:veterinary; D011374:Progesterone / Q000097:blood; D011897:Random Allocation; D013739:Testosterone / Q000097:blood
D006063:Chorionic Gonadotropin; D005300:Fertility Agents, Female; D006064:Gonadotropins, Equine; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D007265:Inhibins; D005640:Follicle Stimulating Hormone; D015237:Dinoprost