Effects of intraovarian infusion of insulin-like growth factor-I on ovarian follicular function in cattle.
The objective of this study was to determine if increased secretion of intraovarian insulin-like growth factor-I (IGF-I), experimentally induced via minipumps, affects follicular function in cattle. Fourteen cycling Holstein cows were divided equally into two groups: Control, osmotic minipumps (containing vehicle) surgically inserted into each ovary, or IGF-I treated, osmotic minipumps as in Controls but pumping 2.0 microg of recombinant human IGF-I per hr for 7 days. All cows were synchronized with prostaglandin F(2alpha) 0.10) between Control and IGF-I-treated cows during Days 2 to 6 of treatment. IGF-I treatment increased (P<0.05) estradiol concentrations in follicular fluid of small follicles, but had no effect (P<0.10) on estradiol concentrations in follicular fluid of large follicles, or on progesterone, androstenedione, or IGF binding protein concentrations in small or large follicles. We conclude that a 7-day infusion of IGF-I directly into the stroma of the ovary altered follicular growth and follicular fluid estradiol concentrations.
Spicer
L J
LJ
Department of Animal Science, Oklahoma State University, Stillwater, OK 74078, USA. igf1Leo@okstate.edu
Alvarez
P
P
Prado
T M
TM
Morgan
G L
GL
Hamilton
T D
TD
D000818:Animals; D002417:Cattle / Q000502:physiology*; D005260:Female; D015571:Follicular Fluid / Q000737:chemistry; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D008024:Ligands; D009929:Organ Size / Q000187:drug effects; D006080:Ovarian Follicle / Q000187:drug effects / Q000502:physiology*; D011863:Radioimmunoassay / Q000662:veterinary
D008024:Ligands; D007334:Insulin-Like Growth Factor I