Bovine blastocyst development after follicle-stimulating hormone and platelet-derived growth factor treatment for oocyte maturation in vitro.

Bovine embryonic viability after in vitro fertilisation (IVF) was affected by addition of platelet-derived growth factor (PDGF) or growth factor combinations to gonadotrophin-supplemented serum-free medium for in vitro maturation (IVM). Thus, 0.1, 1.0 or 10.0 ng PDGF/ml combined with 500 ng follicle-stimulating hormone (FSH)/ml enhanced oocyte maturation as reflected by greater proportions (p < 0.05) of matured and inseminated oocytes developing to blastocysts in vitro than were afforded by PDGF alone, i.e. 32.4%, 28.2% and 31.0% respectively vs. 11.4%, 13.5% and 8.6% respectively. By contrast, luteinising hormone (LH, 500 ng/ml) combined with the same concentrations of PDGF did not increase the proportions of oocytes developing to blastocysts (16.2%, 12.5% and 16.9%). Epidermal growth factor (EGF) + insulin-like growth factor-I (IGF-I) with or without PDGF when added to low concentrations of FSH or LH did not significantly improve cleavage or morula development. Significant improvement (p < 0.05) in blastocyst formation was seen when FSH was supplemented with either EGF (38.0%) or EGF+IGF-I+PDGF (40.7%) compared with FSH alone (27.4%) or FSH+LH (24.3%), but no improvement followed FSH+EGF+IGF-I (33.6%) or FSH+LH+EGF+IGF-I+PDGF (29.2%) treatments for IVM. Results revealed a positive influence on blastocyst development of FSH and PDGF or EGF +/- PDGF during IVM and suggest the possibility of a concerted action of gonadotrophins with growth factors in physiological (functional) oocyte maturation.