چكيده لاتين :
Background: Effec t of diffe rent doses of cysteam ine on rate
of in vitro maturation (lYM), in vitro fertili zati on (l YF) and
glutathio ne (GSH) leve l was studied. Metaph ase II (MIl)
spindle area was analy zed for quant ificat ion of shape and
s ize of oocy tes.
Methods: Female mice were primed with 5 IU of pregnant
mareי s stimulating gonado trophin. Germina l ves icle (GY)
oocytes were ret rieved 48 hrs later. IYM medium was supplemented
with 0, 50, 100, 200 and 500 mM of cysteamine.
For IYM and IYF asse ssme nt in each group, 150 GY oocytes
were used . Experiments also inc luded a gro up of ovulated
oocytes (matured in vi vo ) after prim ing with pregnan t mareיs
stimulating gonadotrophin and human ch or ionic gonado tropin
. GSH level was measu red by 5,5-Dithio-bis
(2nitroben zoic acid) DTNB-GR recyclin g protocol in GY
and MIl oocytes. For IYF, Mil oocy tes were insemina ted
with mature mouse spe rm and rate of two-cell embryo was
measured . For immunocytochemi stry of microtubul e and
chromoso mes, Mil oocy tes were fixed by methano l and immunostain
ed with (L- and ~ - m icro t u bu le ant ibody and
Hoechst. The spindle area was then ana lyzed.
Results: A dose-dependent improvemen t was obse rved in
lYM and IYF rate. Mil developm ent and two-cell emb ryo
formation were increased sign if icant ly in group which received
200 urn cystea mine compare to the contro l gro up.
GSH level was increased in presence of cys team ine in group
which received 200 urn cysteamine. Spindle area was increased
in all gro ups in vitro except for the group which rece
ived 500 urn cysteamine. The difference between spindle
area in 200 urn cys teamine and in vivo group was not s ignificant
(P>0.05).
Conclusion: Administration of cysteamine improves IYM and
IYF rate in a dose-dependant manner. Also cysteami ne induces
glutathion e synthesi s in Mll oocyte and improves
microtub ule when administered at a dose of 200 urn. Therefore,
addit ion of cysteamine as an antiox idant can improve
IYM and IYF rate by increasing of oocytes qualit y.
