Effect of Follicular Fluid Treatment on Follicle-Stimulating Hormone, Luteinizing Hormone and Compensatory Ovarian Hypertrophy in Prepuberal Gilts 1

Prepuberal 130-day-old gilts were treated with 10 ml of charcoal-stripped porcine serum (PS), whole porcine follicular fluid (WpFF) or charcoal-stripped pFF (CpFF) twice daily beginning the day before and continuing 8 days after unilateral ovariectomy (ULO). Follicle-stimulating hormone (FSH) declined for the first 14 h after ULO in WpFF and CpFF gilts and then by 24 h returned to values observed at or before ULO, whereas FSH was increased nearly twofold at 14 h in PS gilts. At 8 days after ULO the remaining ovaries from PS-treated gilts were heavier than ovaries from follicular fluid-treated gilts. In a second experiment, ovariectomized 130-day-old gilts were assigned to either a group infused with PS, a group infused with 5 ml CpFF, or a group infused with 10 ml Cpff at 18 and 2 h before a gonadotropin-releasing hormone (GnRH) challenge. Porcine follicular fluid had no effect on luteinizing hormone (LH) response to GnRH, depressed the FSH response to a 10-μG challenge of GnRH, but had no effect on FSH response to a 50-μG challenge of GnRH. In a third study, gilts were subjected to sham ovariectomy (Sham) or ULO at 130 days of age. GnRH (10 μG) was given on Days 1, 2 or 8 after surgery. The response to GnRH in ULO versus Sham gilts did not differ for FSH or LH on any day. It was concluded that porcine follicular fluid treatment will inhibit the ovarian compensatory response to ULO, but it remains unclear whether the effect is exerted through changes in FSH or by directly inhibiting follicular growth at a local level. CpFF will suppress FSH response without affecting LH response to GnRH challenge in chronically ovariectomized prepuberal gifts; however, pituitary responsiveness to GnRH does not change during compensatory ovarian hypertrophy.