superovulation

Superovulation is a crucial component of assisted reproductive technology. Inducing superovulation with Gonadotropin-releasing hormone (GnRH) can lead to ovarian hyperstimulation, potentially affecting reproductive outcomes.

This study aimed to examine the effects of GnRH treatment on superovulation response and embryo recovery in Holstein heifers.

Twenty-one Holstein heifers (age: 135.15 months; weight: 361.05 kg) were selected based on their general health status and ovarian function. All heifers received two consecutive doses of prostaglandin F2α and underwent superovulation. The heifers were inseminated twice: Once at the onset of standing estrus and again 12 hours later. In the treatment group (13 heifers), a single dose of GnRH was administered simultaneously with the second insemination. The superovulation response was evaluated based on the number of corpus luteum (CL), unovulated follicles (UoF), total recovered embryos/ova, and the number of transferable embryos, using logistic regression with the GENMOD procedure in SAS.

The mean number of CL was not significantly greater in the control group (13.6) compared to the GnRH group (11.4). The average number of UoF was similar between the two groups (P = 0.1853). However, the control group had a significantly higher average total number of recovered embryos/ova (7.7) compared to the GnRH group (2.1). Additionally, the control group progesterone more transferable embryos, with an average of 2.5, while the GnRH group averaged 0.7 (P < 0.0062).

Gonadotropin-releasing hormone likely deactivated the oviduct by disrupting the balance of estradiol and estrogen, leading to a reduction in both the total number of embryos and the number of transferable embryos in heifers.

Diabetes, a major metabolic disorder, seems to affect the fertility rates of women in various ways. Due to the uncertainty of the effects of diabetes along with superovulation treatment on the infertility, we investigate the effects of ovulation induction treatment as therapeutic approach on the expression of leukemia inhibitory factor (LIF) and vascular endothelial growth factor A (VEGFA) as two main factors which are involved in the implantation in the streptozotocin (STZ)‑induced type 1 diabetic rats.

Type 1 diabetes was induced by injections of STZ in Wistar rats. The animals were kept in diabetic conditions for 4 weeks, while some were treated with insulin for treatment. After treatment, the ovulation was induced by human menopausal gonadotropin (hMG) and human chorionic gonadotropin (hCG). The rats were then sacrificed and the expression of LIF and VEGFA was checked by immunohistochemistry staining method, and the relative expression of LIF and VEGFA was measured by quantitative reverse transcription polymerase chain reaction (RT‑PCR) and Western blotting methods.

It was observed that diabetes and insulin treatment for diabetes altered the expression of Lif and VEGFA in both mRNA and protein levels. However, superovulation treatment seems to ameliorate this alternation for both factors.

According to our results, diabetes and insulin therapy could alter the expression of Lif and VEGFA genes and proteins that are effective in endometrial receptivity and implantation process. It seems in diabetic cases, the effect of hCG and hMG therapy by itself could regulate the level of expression and presence of these two genes and proteins.

In this experiment, possible effect of superovulation on important molecular profiles of oocytes and embryos were examined in mice regarding their development. A total of 120 metaphase II oocytes were produced by super or spontaneous ovulation. Blastocyst-stage embryos were produced after in vitro fertilization (IVF) and in vivo fertilization. Blastocysts that have been obtained from naturally mated female without gonadotrophin treatment were also used as controls. Using real-time polymerase chain reaction (PCR), the mRNA expression patterns of Bone morphogenesis protein (Bmp 15(, hepatoma-derived growth factor (Hdgf), DNA methyl transpherase-1 (Dnmt-1), developmental pluripotency associated 3 (Dppa3), and zinc finger protein 57 (Zfp57) genes were compared between superovulated and spontaneously ovulated oocytes; the expression patterns of H19 and small nuclear ribonucleoprotein N) Snrpn( imprinting genes between embryos produced from these oocytes were also compared. The results of the study showed that expression of five maternal effect genes (Bmp15, Hdgf, Dnmt-1, Dppa3, and Zfp57) in superovulated oocytes were significantly reduced (P<0.05). However, the rates of cleavage to the blastocyst stages were not significantly different (P<0.05) between superovulated and naturally ovulated oocytes in cultured embryos. Moreover, superovulation disturbed the expression patterns of imprinting genes (H19 and Snrpn) in single blastocysts obtained by different assisted reproductive techniques (ARTs). The findings indicated that superovulation affected the molecular characteristics of ART conceived embryos.

There is growing interest in the use of progesterone receptor modulators (e.g., mifepristone) for the treatment of gynecologic and other conditions. The aim of this study was to investigate the effects of antiprogesterone (RU486) on the ultrastructure of endometrial in the super ovulated mice at implantation window.
Adult male and female mice were used for the induction of pseudopregnancy. The mice were divided into two experimental and control groups. The Experimental group was further subdivided into two groups based on hormone injection: 1) antiprogesterone and 2) hyperstimulation antiprogesterone. The control group did not get any hyperstimulation. All groups’ uteruses were collected after 4.5 days of pregnancy and were prepared for the assessment of the histological changes with light microscopy (LM) and Transition Electron Microscopy (TEM).
The results showed that antiprogesterone injection decreases the height of microvilli and pinopods in the apical cell in comparison to the control group. Antiprogesterone injection increases the inflammatory cells in the lamina propria of endometrium. The histomorphometrical results indicated that endometrial luminal epithelium height in the hyperstimulation antiprogesterone group was significantly different compared to the control group (P These findings demonstrate that the use of mifepristone is associated with histological changes in the endometrium.

Retinoids have been suggested to play a role in oogenesis and oocyte survival.

In the present study the effects of retinol palmitate were investigated on differentialfollicular counts in response to superovulation as well as follicle quality after vitrification of ovaries.

Ten, 4 week old female BALB/c mice were randomly assigned to eitherparaffin (n=5) or retinol palmitate (n=5) administration. Vitamin A administered animals received(i.p.) 250 IU retinol palmitate, dissolved in 0.1 ml of paraffin oil on days one and ten followed bysuperovulation with 10 IU PMSG. Paraffin administered mice were only treated with 0.1 ml ofparaffin oil. The collected left ovaries from both paraffin and vitamin A administered groups wereconsidered as non-vitrified and the collected right ovaries from both treated groups underwentvitrification. Ovaries in the vitrified group were frozen sequentially by placing into two vitrificationsolutions {VS1: 10% ethylene glycol (EG), 10% DMSO in holding medium (TCM-199 + 20% FBS:HM) and VS2: 20% EG, 20% DMSO in HM}. After warming, recovered ovaries as well as nonvitrifiedovaries were serially sectioned and examined histopathologically.

The proportion of antral follicles in the non-vitrified ovaries from vitamin A administeredmice was statistically higher than the non-vitrified ovaries from paraffin administered group (29.4%vs. 15.6%, respectively; p<0.001). No difference due to retinol palmitate injection was observed forthe rate of small follicles between the two non-vitrified groups. The percentage of damaged folliclesdid not show any significant differences between the two vitrified groups (76% vs. 79%).

Our results demonstrate that administration of retinol palmitate may improve theresponse to superovulation through the shift of follicular growth towards antral follicle development.However, no positive effect of retinol palmitate in the quality of follicles is probable when ovariesare vitrified.