Defined oocyte collection time is critical for reproducible in vitro fertilization in rats of different strains

Time elapsed between ovulation and insemination determines the quality of fertilized rat oocytes

Genetically modified rats are valuable models in human disease research. We recently developed an improved system for rat sperm cryopreservation and in vitro fertilization (IVF) that facilitates the efficient production and preservation of genetically modified rats. In the IVF procedure performed using frozen-thawed rat sperm, the IVF schedule is fixed to ensure timely hormone administration and oocyte collection. To enhance the flexibility of the IVF schedule, possible periods of postovulated rat oocytes with normal fertility and developmental abilities should be determined. Therefore, in this study, we examined the fertilization and developmental ability of incubated oocytes 1-13 h after oocyte collection at 9:00 AM. The fertilization rate decreased 7 h after oocyte collection, and abnormally fertilized oocytes appeared 10 h after oocyte collection. The developmental rate also decreased 7 h after oocyte collection; however, live pups were obtained from oocytes 12 h after oocyte collection. In summary, ovulated rat oocytes exhibited a high developmental ability after IVF for up to 4 h after oocyte collection.

The Effectiveness of Granulocyte Colony-Stimulating Factor (G-CSF) Against Experimental Ischemia–Reperfusion Injury in Rat Ovaries and Its Effect on In Vitro Fertilization Outcomes

Local ischemic damage resulting from ovarian torsion is a common cause of decreased follicular activity and infertility. It was aimed to evaluate the effect of granulocyte colony-stimulating factor (G-CSF) protection on in vitro fertilization (IVF) results against experimental ischemic (I) and ischemic-reperfusion (I/R) injury in rat ovaries. The study consisted of 35 adult female Sprague-Dawley albino rats (sham, ischemia, I/R, I + G-CSF, and I/R + G-CSF) randomly assigned to 5 groups, each containing 7 rats. While bilateral adnexal torsion was applied to the ischemia groups for 3 h, detorsion was applied to the reperfusion groups. Intraperitoneal 100 IU/kg G-CSF was administered 30 min prior to ischemia (I + G-CSF) or reperfusion (I/R + G-CSF). After ovulation induction (intraperitoneal 150-300 IU/kg PMSG), the oocytes were collected and IVF was applied. Statistically significant differences were observed between the collected oocyte numbers in I and I + G-CSF, I/R, and I/R + G-CSF groups (P values were P = 0.001 for the I-I + G-SCF groups and P = 0.003 for I/R-IR + G-CSF, respectively). An increase in the number of MII oocytes obtained was observed in the I + G-CSF and I/R + G-CSF groups compared to the I and I/R groups. Grade 1 and grade 2 embryo numbers were statically different between the I/R and I/R + G-CSF groups (P values were P = 0.023 for grade 1 embryos and P = 0.045 for grade 2 embryos, respectively). G-CSF treatment was found to be effective in reducing I- and I/R-induced ovarian damage.

The effect of protection of platelet-rich plasma against experimental ischemia/reperfusion injury in the rat ovary on in vitro fertilization outcomes

OBJECTIVE

Ovarian torsion is a common cause of local ischemic damage, reduced follicular activity and infertility. This study aimed to investigate how well platelet-rich plasma (PRP) protects against experimental ischemic (I) and ischemia-reperfusion (I/R) injury in rat ovaries and its effect on in vitro fertilization (IVF) outcomes.

METHOD

Fifty-six adult female Sprague-Dawley albino rats were randomly assigned to six groups of eight animals each: Sham, Ischemia, I/R, Sham + PRP, I + PRP, and I/R + PRP. The remaining eight animals were used to prepare the PRP. The ischemia groups were subjected to bilateral adnexal torsion for 3 h, while the I/R and I/R + PRP groups received subsequent detorsion for 3 h. Intraperitoneal (i.p.) PRP was administered 30 min prior to ischemia (I + PRP) or reperfusion (I/R + PRP). The ovaries were stimulated through an intraperitoneal injection of 150-300 internal units of IU/kg PMSG. After ovulation induction, oocytes were taken from the ovaries, and IVF was performed.

RESULTS

The number of MII oocytes reached the highest number with 4.63 ± 0.74 in the S group and had the lowest number with 0.50 ± 0.53 in the I/R group. There were statistically significant differences for the number of embryos obtained on the second day between the I and I + PRP groups and the I/R and I/R + PRP groups (p = 0.000). In comparing anti-Müllerian hormone 1 (AMH1) and AMH2 values within the group, the highest decrease was observed in the I and I/R groups.

CONCLUSION

PRP is effective in minimizing ovarian damage and preserving ovarian reserves following ovarian torsion.

Protective Effects of Platelet-rich plasma for in vitro Fertilization of Rats with Ovarian Failure Induced by Cyclophosphamide

OBJECTIVE

 Premature ovarian insufficiency (POI) contributes significantly to female infertility. Cyclophosphamide (CYC has adverse effects on folliculogenesis. Platelet-rich plasma (PRP) is an autologous product rich in many growth factors. We evaluated the protective effect of PRP on in vitro fertilization in female rats with CYC-induced ovarian damage.

METHODS

 Twenty-eight adult female Sprague-Dawley rats were randomly divided into four groups. Group 1 (control-sodium chloride 0.9%; 1 mL/kg, single-dose intraperitoneal [IP] injection); group 2 (CYC), 75 mg/kg, single-dose IP injection and sodium chloride 0.9% (1 mL/kg, single-dose IP injection); group 3 CYC plus PRP, CYC (75 mg/kg, single-dose and PRP (200 μl, single-dose) IP injection); and group 4 (PRP, 200 μl, single-dose IP injection).

RESULTS

 In the comparisons in terms of M1 and M2 oocytes, it was observed that the CYC group presented a significantly lower amount than the control, CYC/PRP, and PRP groups. (for M1, p = 0.000, p = 0.029, p = 0.025; for M2, p = 0.009, p = 0.004, p = 0.000, respectively). The number of fertilized oocytes and two-celled good quality embryos was found to be statistically significant between the CYC and control groups, CYC + PRP and PRP groups (p = 0.009, p = 0.001, p = 0.000 for oocytes, respectively. For embryos; p = 0.016, p = 0.002, p = 0.000).

CONCLUSION

 Platelet-rich plasma can protect the ovarian function against damage caused by CYC, and, in addition, it improves oocyte count and the development of embryos as a result of oocyte stimulation during the IVF procedure.

The effect of Propofol versus Dexmedetomidine as anesthetic agents for oocyte pick-up on in vitro fertilization (IVF) outcomes

This study aimed to evaluate the effects of propofol and dexmedetomidine over different timescales on the IVF outcomes for transvaginal oocyte retrieval (TVOR). Twenty-four rats included in the study were divided into two main groups and three subgroups were subjected to the ovulation induction process. Group 1 was administered propofol (100 mg/kg i.v.) and group 2 were administered dexmedetomidine (25 µg/kg i.p.) The oviduct collection procedure was completed within 15 min for subgroup Pro15min, Dex15min (n = 4), within 16 to 30 min for subgroup Pro30min, Dex30min (n = 4) and within 31 to 60 min for subgroup Pro60min, Dex60min (n = 4) after euthanasia. The total number of oocytes was counted. After in vitro fertilization, the number and quality of embryos were evaluated. The number of pups born were evaluated after embryo transfer. The embryo number, quality and pup count decreased as the administration time for propofol increased (p < 0.05). No statistically significant difference was found between the dexmedetomidine subgroups for embryo number, quality and pup count(p > 0.05). As the exposure time to propofol increased, the number and quality of embryos obtained, and the pup count, decreased. The use of dexmedetomidine had no negative impacts on the number of embryos, their quality or the number of pups.