Effects of growth hormone and insulin-like growth factor-I on development of in vitro derived bovine embryos.
The objectives of this study were to determine whether the addition of growth hormone (GH) to maturation medium and GH or insulin-like growth factor-I (IGF-I) to culture medium affects development of cultured bovine embryos. We matured groups of 10 cumulus-oocyte complexes (COCs) in serum-free TCM-199 medium containing FSH and estradiol with or without 100 ng/ml GH. After fertilization, we transferred groups of 10 putative zygotes to 25 microl drops of a modified KSOM medium containing the following treatments: non-specific IgG (a control antibody, 10 microg/ml); GH (100 ng/ml) + IgG (10 microg/ml, GH/IgG); IGF-I (100 ng/ml) + IgG (10 microg/ml, IGF/IgG); antibody to IGF-I (10 microg/ml, anti-IGF); GH (100 ng/ml) + anti-IGF (10 microg/ml GH/anti-IGF); IGF-I (100 ng/ml) + anti-IGF (10 microg/ml, IGF/anti-IGF); no further additions (control). We repeated the experiment six times. Adding GH to the maturation medium increased cleavage rates at Day 3 compared to control (87.3 +/- 1.2% > 83.9 +/- 1.2%; P < 0.05) but had no effects on blastocyst development at Day 8. At Day 8, blastocyst development was greater (P < 0.01) for GH/IgG (24.8 +/- 2.5%) and IGF/IgG (33.7 +/- 2.5%) than for IgG (16.1 +/- 2.1%) and greater for IGF/IgG than for GH/IgG (P < 0.02). Blastocyst development at Day 8 did not differ between anti-IGF (20.4 +/- 1.8%) and GH/anti-IGF (24.1 +/- 1.9%) or IGF/anti-IGF (17.7 +/- 1.9%), but it was greater for GH/anti-IGF than for IGF/anti-IGF (P < 0.05). The Day 8 blastocysts of GH/IgG and IGF-I/IgG groups had a higher (P < 0.01) number of cells than the IgG group. The addition of anti-IGF-I eliminated the effects of IGF-I on cell number but did not alter GH effects. In conclusion, both GH and IGF-I stimulate embryonic development in cattle and GH effects may likely involve IGF-I-independent mechanisms.
Moreira
F
F
Department of Aninial Sciences, University of Florida, Gainesville 32611, USA.
Paula-Lopes
F F
FF
Hansen
P J
PJ
Badinga
L
L
Thatcher
W W
WW
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001755:Blastocyst / Q000502:physiology; D002417:Cattle / Q000196:embryology*; D002970:Cleavage Stage, Ovum; D003470:Culture Media; D046508:Culture Techniques; D005314:Embryonic and Fetal Development; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary*; D013006:Growth Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage / Q000276:immunology / Q000494:pharmacology*; D051379:Mice; D011994:Recombinant Proteins / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D003470:Culture Media; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone