a1 College of Veterinary Medicine, University of Georgia, Athens, Georgia, U.S.A.
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.
c1 Dr B.G. Brackett, Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602-7389, USA. Telephone: (706)542-3014. Fax: (706)542-3015.