5690
Amro Mohamed El-sanea
Studies on the effect of some antioxidants on the
developmental competence of buffalo oocytes
buffalo, oocytes, ovary, seasons, oxygen tension, antioxidants.
The present study was carried out to evaluate: 1) The effect of seasons of the year and addition of some antioxidants (ascorbic acid, glutathione and melatonin) into in vitro maturation (IVM) medium on the developmental competence of buffalo oocytes, also 2) The effect of addition of different concentrations of ascorbic acid, glutathione or melatonin to in vitro fertilization (IVF) medium on buffalo sperm motility and viability. For this purpose, six experiments were conducted. In experiment1, ovaries were collected from Elmoneib and Al-badrashine slaughterhouses in Giza Governorate during whole year and the number of ovarian follicles, oocyte yield/ovary and oocyte quality was estimated. In experiment 2, buffalo oocytes were matured during different seasons in BMM and the IVM rate was estimated. In experiment 3, mitochondrial activities in non-matured and matured buffalo oocytes were assayed. In experiment 4, buffalo oocytes were matured under 5% O2 or 20% O2 tension and maturation, cleavage and embryo developmental rates were assayed. In experiment 5, buffalo oocytes were matured in BMM or BMM to which 50µM ascorbic acid, 3mM glutathione or 10µM melatonin were added. In vitro matured oocytes were subjected to IVF. Maturation, cleavage and embryo developmental rates were assayed. In experiment 6, frozen-thawed buffalo spermatozoa were incubated in fertilization medium with different concentrations of ascorbic acid (25 µM, 50µM or 100 µM), glutathione (2mM, 3mM or 5mM) or melatonin (10-4M, 10-5M or 10-6M) for three hours and sperm motility and viability were estimated every hour. Results showed that summer decreased the number of ovarian follicles, the quality of oocytes, cumulus-cell expansion and nuclear maturation of IVM buffalo oocytes. Matured buffalo oocytes expressed clustering homogenous distribution, while, non-matured oocytes showed polarized mitochondrial distribution. Culture of buffalo oocytes under low O2 (5% O2) did not affect oocytes maturation, but it increased cleavage and blastocyst rates. Addition of 10-5M melatonin or 50 µM ascorbic acid to IVM medium of buffalo oocytes significantly (P<0.05) improved cumulus-cell expansion and nuclear maturation rates of IVM buffalo oocytes and increased (P<0.05) cleavage and blastocyst rates of buffalo embryos. Addition of 10-5 or 10-4M melatonin to fertilization medium increased sperm viability up to 3 h of incubation compared with other groups.
2021
Ph.d
Cairo
Veterinary Medicine