Effects of monopotassium phosphate and oviduct cells on the in vitro fertilized mice embryos development

The study investigated the effects of three different KH₂PO₄ concentrations (0.59 mM; 1.19 mM; 2.38 mM) in Whitten’s medium and co-culture on in vitro two-cell blocks and their development to the blastocyst stage of inbred BALB/C mice embryos following in vitro fertilization. Standard IVF and IVC procedures were used and mouse oviduct cells were used as a co-culture. The results demonstrated that various concentrations of potassium were not effective on the cleavage rates. 1.19 mM KH₂PO₄ with and without co-culture groups (P<0.05)had the highest rate of reaching the 4-to 6- and 8-cells. At the 72nd hour, the 1.19 mM KH₂PO₄ groups without (55.26%) and with co-culture (44.77%) (P<0.05) displayed the most satisfactory development to the morula stage. Although 0.59 mM and 2.38 mM KH₂PO₄ were found to be insufficient to develop up to morula, 0.59 mM KH₂PO₄ with co-culture may have beneficial effects (31.57%; P<0.05). On the other hand, despite the high concentration of KH₂PO₄ (16.90%) supporting a more effective development rate to the morula than the lower level (P<0.05), it was noted that co-cultures having a high KH₂PO₄ were not beneficial. KH₂PO₄ with and without (30.00%) co-culture (26.01%) (P<0.05) demonstrated the most beneficial development of the blastocyst stage.