Supplementation of EGF, IGF-1, and Connexin 37 in IVM Medium Significantly Improved the Maturation of Bovine Oocytes and Vitrification of Their IVF Blastocysts.

The quality and developmental capacity of oocytes derived from in vitro maturation (IVM) remain unsatisfactory, which greatly impairs the efficiency and application of embryo technologies. The present experiment was designed to investigate the effect of the supplementation of EGF, IGF-1, and Cx37 in an IVM medium on the maturation quality and development ability of bovine oocytes. The cytoplasmic maturation events of oocytes and the quality of in vitro fertilization (IVF) blastocysts were examined to investigate the relative mechanisms. Our results showed that the nuclear maturation and blastocyst development after the IVF of oocytes treated with 25 µg/mL Cx37 or the combination of 50 ng/mL EGF and 100 ng/mL IGF-1 were significantly increased compared to those of the control group (p < 0.05). Furthermore, the blastocyst rate, and blastocyst total cell number and survival rate after vitrification of the EGF+IGF-1+Cx37 group, were significantly higher than those of the control group (p < 0.05), but lower than those of the FSH+LH+EGF+IGF-1+Cx37 group (p < 0.05). The transzonal projection (TZP) intensity, glutathione (GSH) level, and mitochondrial function of the EGF+IGF-1+Cx37 group were significantly higher than that of the control group, and lower than those of the FSH+LH+EGF+IGF-1+Cx37 group, in contrast to the results of the reactive oxygen species (ROS) levels. In conclusion, our results showed that the supplementation of 50 ng/mL EGF, 100 ng/mL IGF-1, and 25 µg/mL Cx37 in the IVM of bovine oocytes significantly improved their quality and developmental ability by increasing the TZP, mitochondrial function, and GSH level.

Unexpected effect of the vehicle (grain ethanol) of homeopathic FSH on the in vitro survival and development of isolated ovine preantral follicles.

The aims of this study were to investigate the effects of medium replacement system (experiment I) and of FSH presentations (homeopathic - FSH 6cH and allopathic FSH - rFSH; experiment II) on the in vitro development, hormone production and gene expression of isolated ovine preantral follicles cultured for 6 days. In experiment I, secondary follicles were cultured in the α-MEM+ supplemented with FSH 6cH (0.05 fg/ml) or recombinant bovine FSH (100 ng/ml) without/with daily medium addition. The homeopathic FSH treatments with/without medium addition improved (p < .05) follicular development compared to rFSH100 treatment without addition. FSH 6cH with addition showed the highest (p < .05) estradiol production. To verify whether the effects of homeopathic FSH were not due to its vehicle, experiment II was performed. The α-MEM+ was supplemented or not with alcohol (0.2% grain ethanol, v/v), FSH 6cH or rFSH100 with daily medium addition. Surprisingly, we found that all treatments improved follicular development compared to the α-MEM+ (p < .05). Moreover, homeopathic FSH was similar to the other treatments including its vehicle. In conclusion, its vehicle (ethanol) causes the effect of homeopathic FSH on in vitro development of isolated ovine preantral follicles.