Ck. Park et al., EFFECT OF SUPEROXIDE-DISMUTASE (SOD) ON PRONUCLEUS FORMATION OF PORCINE OOCYTES FERTILIZED IN-VITRO, Theriogenology, 48(7), 1997, pp. 1137-1146
This study was undertaken to evaluate the effects of superoxide dismut
ase (SOD) on pronucleus formation in porcine oocytes fertilized in vit
ro by frozen-thawed spermatozoa. No differences were found in penetrat
ion rates when SOD was added to maturation or fertilization medium at
any level tested in first and second experiments. Pronucleus formation
rates were higher (P<0.05) when SOD at 10 and 100 units was added to
the maturation medium (46 and 53%, respectively) compared with the con
trols (26%). On the other hand, when the fertilization medium was supp
lemented with SOD at different concentrations (1, 10 and 100 units/ml)
, pronucleus formation rates (55, 52 and 50%) were significantly highe
r (P<0.05) than in the control group. In third experiment, the oocytes
were cultured in medium with (1 unit/ml) or without SOD for 8, 16, 24
and 32 h after insemination. The penetration rates had a tendency to.
increase as time of sperm-oocyte culture was prolonged. No significan
t differences, however, were observed in penetration rates between gro
ups with and without SOD. On the other hand, the pronucleus formation
rates were higher in medium with than without SOD at 8 (7 vs 0%), 16 (
14 vs 3%), 24 (48 vs 16%; P<0.01) and 32 h (49 vs 22%; P<0.05). These
findings demonstrate the advantage of culture with SOD on pronucleus f
ormation in porcine oocytes penetrated by spermatozoa However, SOD doe
s not affect penetration rates and polyspermy. (C) 1997 by Elsevier Sc
ience Inc.