The Effect of Angiotensin on the Quality of In Vitro Produced (IVP) Sheep Embryos and Expression of Na+/K+/ATPase

BACKGROUND The presence of rennin-angiotensin components in mammalian ovaries and their involvement in ovarian physiology have been established. In the present study, effects of angiotensin II (Ang II) on sodium-potassium adenosine triphosphatase (Na(+)/K(+)/ATPase) expression and development of sheep embryos was evaluated. METHODS The abattoir-derived Cumulus Oocyte Complexes (COC) were randomly allocated into three experimental groups; group I) in vitro Maturation (IVM) of oocytes in the presence of Ang II followed by in vitro fertilization (IVF)/in vitro Culture (IVC) (IVM group), group II) IVM/IVF of oocytes followed by IVC wherein the embryos were exposed to Ang II on day 4 of IVC (D4 group), and group III) IVM/IVF and IVC of oocytes without any angiotensin (Control). The blastocyst and hatching rates were recorded on days 6 to 8. Day 8 embryos were immunostained with primary and secondary antibodies against Na(+)/K(+)/ATPase α1 and β1 subunits. RESULTS Addition of Ang II during IVM and IVC significantly increased the hatching rate of blastocysts on day 8 compared to the control. The trophectoderm and total blastocyst cells' numbers were significantly increased by addition of Ang II to the IVM and IVC media, though the expression of Na(+)/K(+)/ATPase α1 and β1 subunits were positively influenced by the addition of Ang II on day 4 (D4 group). CONCLUSION In conclusion, it seems Ang II through positive effects on embryos, expressed as the greater hatching rate and blastocyst cell number, could increase the sheep embryo developmental rate. These improvements might be partly related to the greater expression of Na(+)/K(+)/ATPase α1 and β1 subunits when Ang II was added during IVC.