Relationship between concentrations of immunoreactive insulin-like growth factor-I in follicular fluid and various biochemical markers of differentiation in bovine antral follicles.
Three experiments were conducted to determine the relationship between concentrations of insulin-like growth factor-I (IGF-I) in ovarian follicular fluid and various biochemical markers of follicular differentiation in bovine follicles. In Experiment I, ovaries were removed on Days 7, 14, 28, 42, or 56 after parturition from a total of 21 cows. In Experiment II, ovaries of 31 cows were removed between Days 20 and 30 postpartum after 48 or 96 h of either saline (0.9% NaCl, 5 ml) or luteinizing hormone-releasing hormone (LHRH, 500 ng/5 ml saline) injections given every 2 h via jugular cannulae. In Experiment III, ovaries of six cows were removed 48-50 h after a 35-mg injection of prostaglandin F2 alpha during the midluteal phase of an estrous cycle. In Experiments I and II, all follicles greater than or equal to 8.0 mm in diameter were removed from each ovary (n = 33 and 46, respectively). In Experiment III, fluid from all follicles greater than 4 mm in diameter were removed individually (n = 10), and fluid from follicles 1-4 mm in diameter were pooled for each cow. Follicles for each experiment were further categorized as either estrogen-active (E-A, concentration of estradiol greater than progesterone in follicular fluid) or estrogen-inactive (E-I, concentration of progesterone greater than estradiol in follicular fluid). Measurements of immunoreactive IGF-I (i-IGF-I) were made after separating IGFs from their binding proteins with an acid-ethanol extraction.(ABSTRACT TRUNCATED AT 250 WORDS)
Spicer
L J
LJ
Department of Medicine, Milton S. Hershey Medical Center, PennsylvaniaState University, Hershey 17033.
Echternkamp
S E
SE
Canning
S F
SF
Hammond
J M
JM
D000735:Androstenedione / Q000032:analysis*; D000818:Animals; D001826:Body Fluids / Q000032:analysis; D002417:Cattle / Q000502:physiology*; D004958:Estradiol / Q000032:analysis*; D005260:Female; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D006080:Ovarian Follicle / Q000032:analysis*; D011374:Progesterone / Q000032:analysis*; D013002:Somatomedins / Q000032:analysis*
D013002:Somatomedins; D000735:Androstenedione; D011374:Progesterone; D004958:Estradiol; D007334:Insulin-Like Growth Factor I