Ischaemia-reperfusion injury of rat ovary and the effects of vitamin C, mannitol and verapamil

The effect of vitamin C on the recovery of activity and survival of autografted ovaries through inhibition of oxidation and inflammation

Ovarian tissue autografting is a valuable clinical option to help restore fertility in women with cancer. However, many follicles are lost due to ischemia-reperfusion (IR) injury, which depletes follicles after grafting. We aimed to investigate the effect of vitamin C, an antioxidant with anti-apoptotic and anti-inflammatory properties, on improving the structure and function of autografted ovaries in mice. Thirty-six female NMRI mice (4-5 weeks old) were divided into three groups of 12: control (no grafting), autograft + vitamin C (50 mg/kg/day intraperitoneally), and autograft + saline (100 µl/day/animal, intraperitoneally). After the ovarian autografting and before the start of the experiment, each group was further divided into 7-day and 28-day subgroups. Seven days after ovary autografting, serum levels of malondialdehyde (MDA), total antioxidant capacity (TAC), and inflammatory factors were measured. On day 28, ovarian histology, DNA fragmentation, and estradiol and progesterone levels were assessed. Results were analyzed using one-way ANOVA and Tukey's test, with significance set at p<0.05. In the autograft + vitamin C group, there were significant increases in the mean total volume of the ovary, cortex (p<0.05), medulla, number of follicles, and levels of IL-10, progesterone, estradiol, and TAC (p<0.001), compared to the autograft group. Conversely, the rate of apoptosis and serum levels of MDA, IL-6, and TNF-α were notably reduced in the autograft + vitamin C group (p<0.001). These results suggest that vitamin C can significantly enhance the recovery of autografted ovaries through its antioxidant, anti-inflammatory, and anti-apoptotic effects.

The Role of Mannitol and Vitamin D in Ovarian Ischemia/Reperfusion Injury in Rats with Acute Abdominal

This study was designed to investigate the effects of vitamin D and mannitol in an experimental rat ovarian torsion model. Thirty-two female Wistar albino rats were randomly classified as group 1: (sham), group 2: (detorsion), group 3: (detorsion + mannitol), group 4: (detorsion + vitamin D) and group 5: (detorsion + mannitol + vitamin D) (for each group n = 8). All groups were subjected to bilateral adnexal torsion for 2 h except for group 1. Bilateral adnexal detorsion was performed in all groups except for group 1. Groups 3 and 5 intraperitoneally received the injection of mannitol at a dose of 0.3 mg/kg 30 min before detorsion. Also, the group's 4 and 5 orally received vitamin D in a dose of 500 IU/kg/day for two weeks before torsion. Total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI) and proliferating cell nuclear antigen (PCNA) levels were analyzed. According to the histopathological analyses, ovarian tissue damage and follicle counting were evaluated. TOS, OSI and histopathologic score values of ovarian tissue were significantly lower in group 5 than groups 2, 3 and 4 (p < 0.05). The PCNA level was significantly higher in group 5 than in groups 2, 3 and 4 (p < 0.05). A strong negative correlation was found between OSI and PCNA in groups 2, 3, 4 and 5 (r = -0.92, p = 0.01; r = -0.98, p < 0.0001; r = -0.98, p < 0.0001 and r = -0.96, p = 0.0002, respectively). The numbers of primordial follicles in group 5 (p < 0.001) and primary follicles in group 4 (p < 0.001) were significantly higher when compared to group 2. Based on the results of this study, it could be suggested that combination treatment of mannitol with vitamin D is more effective in reversing tissue damage induced by ischemia-reperfusion (I/R) injury in the ovarian torsion model than administration of only an agent.

Comparison of salpingectomy and tubal detorsion procedures after experimental ischemia-reperfusion injury in a rat fallopian tube model: biochemical and histopathological evaluation

OBJECTIVE

To compare salpingectomy and detorsion procedures and investigate the biochemical and histopathological changes in the fallopian tubes in the experimentally isolated fallopian tube torsion model in rats.

DESIGN

Experimental study.

SETTING

Experimental surgery laboratory in a training and research hospital.

ANIMAL(S)

Twenty-seven Sprague-Dawley rats in the reproductive period.

INTERVENTION(S)

Group 1, control group (n = 6); group 2, bilateral total salpingectomy group after 4 hours of tubal ischemia (n = 7); group 3: 4 hours of bilateral tubal ischemia plus 1 week of reperfusion (n = 7); and group 4, 4-hour period of bilateral tubal ischemia plus 30 days of reperfusion (n = 7). A 22-gauge catheter was administered before and after surgery using methylene blue through the uterine horn of the rat to evaluate tubal patency.

MAIN OUTCOME MEASURE(S)

Preoperative and postoperative serum antimüllerian hormone (AMH) levels, histopathological examination of the rat tuba uterine and histopathological damage scores, antioxidant compounds (superoxide dismutase [SOD], catalase, and glutathione peroxidase [GSH-Px]), and oxidative stress end product levels (malondialdehyde [MDA] and 8-hydroxy-2'-deoxyguanosine [8-OHdG]).

RESULT(S)

Although a significant difference was observed in the tissue SOD, GSH-Px, MDA, and 8-OHdG values, no significant difference was observed between the groups in serum samples. The tissue SOD and tissue GSH-Px levels in group 2 significantly decreased, and a significant increase was observed in the tissue MDA and 8-OHdG values in group 2. Among the histopathological parameters, epithelial changes, vascular congestion, and the total fallopian tube mean damage score of 4 showed a significant decrease in group 4. When the methylene blue transitions before and after ischemia-reperfusion injury were compared, the values of the methylene blue transition after ischemia-reperfusion injury in groups 2-4 significantly decreased. When the serum AMH levels were analyzed, the postoperative AMH value in group 2 significantly increased.

CONCLUSION(S)

This study reveals that biochemical and histopathological improvement is observed in the fallopian tube tissues gradually when the detorsion procedure is performed for the necrotized tubal tissue instead of salpingectomy. Although there is restoration of epithelial integrity after reperfusion, tubal passage remains absent.

CLINICAL TRIAL REGISTRATION NUMBER

This study was approved by the Local Ethics Committee for Animal Experiments of the Health Sciences University, Istanbul Hamidiye Medicine Faculty (approval number 27.05.2022-9269). The study followed the ethics standards recommended by the Declaration of Helsinki.

The Combination of Estradiol and N-Acetylcysteine Reduces Ischemia-Reperfusion Injuries of Mice Autografted Ovarian Tissue

Ischemia-reperfusion injuries are important issues after ovarian tissue transplantation (OTT). Our study examined the effects of N-acetylcysteine (NAC) and estradiol (E2) on mouse ovarian autografts. Mice (6-8 weeks) were divided into ovarian autograft as follows: Control: fresh OTT; Sham: cryopreserved/warmed OTT; NAC: cryopreserved/warmed OTT with NAC treatment; E2: cryopreserved/warmed OTT with E2 treatment; NAC+E2: cryopreserved/warmed OTT with the treatment of NAC and E2. In all groups, grafts were harvested on days 2, 7, and 28 after transplantation to evaluate histological parameters, inflammation relative to genes expression, and oxidative status. Histological analysis showed that NAC, E2, and a combination of NAC+E2 significantly increased the primordial, preantral, and antral follicular number. When NAC was used, it significantly reduced the expression of Tnf-α and Fgf-2, whereas it increased Il-1β, Il-6, and Vegf expression levels. The levels of Il-6, Fgf-2, and VEGF were dramatically increased in the E2-treated group. The combination of NAC and E2 significantly increased levels of Il-1β, Il-6, Fgf-2, and Vegf. NAC and E2 alone or in combination significantly increased total antioxidant capacity but did not affect the superoxide dismutase and glutathione peroxidase activities. In conclusion, after transplantation, NAC and E2 alone or in combination, could improve follicular development and angiogenesis as well as decline inflammation and ovarian oxidative damage.

The effects of berberine on ischemia-reperfusion injuries in an experimental model of ovarian torsion

OBJECTIVE

Ovarian torsion is a gynecological disorder that causes ischemia-reperfusion injuries in the ovary. Our study investigated berberine's short- and long-term effects on ovarian ischemia-reperfusion injuries.

METHODS

This study included 28 Wistar albino female rats weighing 180 to 220 g, which were divided into four groups: sham (S), torsion/detorsion (T/D), torsion/ detorsion+single dose berberine (T/D+Bb), and torsion/detorsion+15 days berberine (T/D+15Bb). The torsion and detorsion model was applied in all non-sham groups. In the T/D+Bb group, a single dose of berberine was administered, while in the T/D+15Bb group, berberine was administered over a period of 15 days. After the rats were euthanized, their ovaries were excised. The left ovaries were used for histopathologic evaluation, which included ovarian injury scoring and follicle count, while the right ovaries were used for biochemical analyses (tissue transforming growth factor-β [TGF-β] and alpha-smooth muscle actin [α-SMA] levels).

RESULTS

The histopathologic evaluation scores for the ovaries were significantly lower in the T/D+B group (p<0.05) and the T/D+15B group (p<0.005) than in the T/D group. The follicle counts in the T/D group were lower than those in both the sham and treated groups (p<0.005). The TGF-β levels were significantly lower in the T/D+15B group (p<0.005), whereas the α-SMA levels did not show a significant difference.

CONCLUSION

Both short- and long-term berberine use could potentially have therapeutic effects on ovarian torsion. Long-term berberine use exhibited anti-inflammatory effects by reducing TGF-β levels, thereby preventing ischemia-reperfusion injuries. Therefore, we suggest that long-term berberine use could be beneficial for ovarian torsion.

Maternal and paternal obesity differentially reprogram the ovarian mitochondrial biogenesis of F1 female rats

Obesity has harmful consequences on reproductive outcomes and the rapid increase in obesity is assumed to be influenced by epigenetics and trans-generation effects. Our study aimed to explore the effect of maternal and/or paternal obesity on the ovarian tissues of the first-generation female offspring in rats. The study was conducted on 40 adult Wistar albino rats (20 males and 20 females). Obesity was induced by feeding them an obesogenic diet for 3 months. The pregnancy was induced in the females by mating with males in four combinations: healthy mother with healthy father (control parents, CP), healthy mother with obese fathers (OF), obese mothers with healthy father (OM), and obese mother with obese father (obese parents, OP). After delivery, the female offspring at two months were sacrificed, and the blood and ovarian tissues were collected to assess the studied parameters. Our result showed differential impacts of maternal and paternal obesity on the ovarian health of the female offspring. The female offspring of obese OM or OP showed early signs of obesity. These metabolic abnormalities were associated with signs of ovarian lesions, impaired folliculogenesis, and decreased oocyte quality and also showed significant alterations in mitochondrial biogenesis, redox status, inflammation, and microRNAs expression (miR-149 and miR-494). In conclusion, altered ovarian expression of microRNAs and associated impaired mitochondrial biogenesis pathways may be the root causes for the observed intergeneration transmission of the obesogenic phenotype.

Protective effects of sildenafil administration on chemotherapeutic-induced ovarian damage in rats

Agents to reduce the gonadotoxic effects of chemotherapeutics are still under investigation. In this context, we aimed to investigate the protective effect of sildenafil against chemotherapeutic-induced gonadotoxicity in a rat model. A total of 62 female rats were divided into eight groups as control, sildenafil (1.4 mg/kg, orally), doxorubicin (3 mg/kg, i.p.), cisplatin (5 mg/kg, i.p.), cyclophosphamide (200 mg/kg, i.p.), doxorubicin+sildenafil, cisplatin+sildenafil, and cyclophosphamide+sildenafil (1.4 mg/kg orally sildenafil in addition to the same dose of chemotherapeutics). The groups were compared in terms of follicle count, ovarian size, and anti-müllerian hormone (AMH) levels. Use of sildenafil with cyclophosphamide was effective only in preserving primary follicle count (p = 0.026) and had no significant change in the secondary follicle count, ovarian size, or AMH level. Adding sildenafil to cisplatin had a significant protective effect on primary follicle count (p = 0.011), secondary follicle count (p = 0.009), and ovarian size (p = 0.001), but this effect could not be demonstrated at AMH level. Sildenafil was not effective on any parameter in the doxorubicin group. Sildenafil may be effective in reducing the gonadotoxicity associated with the use of cisplatin and cyclophosphamide.

Influence of Systemic Administration of Coq10 Nanoparticles on Ischemia-Reperfusion Injury on Ovaries in Rat

Using a rat ovary model, effects of COQ10 nanoparticles (NCOQ10) were studied on ischemia-reperfusion injury. In the present experimental study, following randomization of thirty healthy female Wistar rats ∼250 g, the animals were subjected to five experimental groups (n = 6): group SHAM : only laparotomy was performed, group IS: only a 3-hour ischemia was performed, group IS/REP: the procedure included a 3-hour ischemia followed by a 3-hour reperfusion, and 50 µL soybean oil (solvent of NCOQ10) was administered 30 min before cessation of reperfusion, group IS/NCOQ10: the procedure included a 3-hour ischemia only and 50 µL (0.3 mmol/lit/IP) of NCOQ10 30 min before cessation of ischemia, and group IS/REP/NCOQ10: the procedure included a 3-hour ischemia, a 3-hour reperfusion, and 20 µL (0.3 mmol/lit) of NCOQ10 30 min before cessation of ischemia. Significantly amended development of ischemia/reperfusion tissue injury was observed in animals treated with NCOQ10 compared to those of other groups (P=0.001). Mean values of biochemical indices were significantly higher than those observed for other groups (P=0.001). Significantly lower values of MDA were observed in IS/REP/NCOQ10 animals compared to those of other groups (P=0.001).Where ovarian tissue is exposed to ischemia, intraperitoneal administration of NCOQ10 could bear clinical benefits in diminishing ischemia-reperfusion injury.

Protective Effect of Lycopene against Reperfusion Injury in Rats with Ovarian Torsion: A Biochemical and Histopathological Evaluation

Objective  The aim of our study was to evaluate the effect of two different doses of lycopene, an antioxidant, on experimentally induced ovarian ischemia/reperfusion (IR) injury in rat model.

Materials and Methods  Twenty-four female rats were randomly divided into four groups: sham operation (group 1), 3-hour ischemia, 3-hour reperfusion (IR) (group 2), and IR + 100 mg/kg lycopene (PO) (group 3), IR + 200 mg/kg of lycopene (group 4). The rats’ superoxide dismutase (SOD), myeloperoxidase (MPO) activities, malondialdehyde (MDA), and glutathione (GSH) levels were calculated. Ovarian tissue damage was assessed using a histopathological scoring system.

Results  Serum parameter levels and histological scores showed that treatment with lycopene may be conservative approach to prevent IR injury after the ovarian detorsion procedure.The improvement with lycopene was higher at 200 mg than at 100 mg. The MPO and MDA values were significantly lower in groups 3 and 4 as compared with group 2 ( p < 0.05), whereas the MPO and MDA values were lower in group 4 as compared with group 3.The SOD and GSH values were significantly higher in groups 3 and 4 as compared with group 2 ( p < 0.05), whereas the SOD and GSH values were higher in group 4 as compared with group 3.Tissue damage scores were elevated in the IR group compared with the sham group, but the treatment with different lycopene doses after reperfusion improved the histopathological tissue damage scores.

Conclusion  The results showed that lycopene treatment reduced ovarian IR damage. Antioxidant activity was found to increase in a dose-dependent manner. Lycopene treatment may be conservative approach for ovarian torsion patients after the detorsion procedure to prevent IR damage.

Efficiency of mannitol-supplemented medium during adding/removing ovarian tissue with penetrating cryoprotective agents

Most protocols to cryopreserve ovarian tissue utilize the permeable cryoprotective agents (CPAs) in 1.5 M concentration. However the issues related to the ability to use higher concentrations of CPAs have remained open. The research aim was to assess the efficiency of media containing osmotically active sugars (sucrose, mannitol) at stepwise adding/removing of 3 M dimethylsulphoxide (DMSO) and propanediol (PROH) on ovarian tissue integrity. After the CPAs adding/removing the ovarian tissue injury was histologically examined, as well as the oocyte volume in tissue structure was assessed. It has been found, that after adding/removing of PROH and DMSO solutions the maximum amount of normal follicles made 67-93% when using Dulbecco's Modified Eagle Medium (DMEM) with 200 mM sucrose. Assessment of tissue damage after adding/removing of CPAs has demonstrated that the percentage of normal follicles was 83-87% using DMSO in presence of both sucrose and mannitol as the dilution media components. While removing PROH the level of follicles preservation was 2.5× higher when using mannitol compared with sucrose. Our results indicate that the ovarian tissue injury was minimal during adding 3 M CPAs using DMEM, containing sucrose and following application of mannitol at removing both DMSO and PROH.

Protective effect of hydrogen rich saline solution on experimental ovarian ischemia reperfusion model in rats

BACKGROUND

The present study aimed to investigate the effects of hydrogen rich saline solution (HRSS) in a rat model of ovarian ischemia-reperfusion injury.

METHODS

Thirty-six female Wistar-albino rats were grouped randomly, into six groups of six rats. The groups were classified as: sham (S), hydrogen (H), torsion (T), torsion/detorsion (TD), hydrogen-torsion (HT), and hydrogen-torsion/detorsion (HTD). Bilateral adnexal torsion was performed for 3h in all torsion groups. HRSS was given 5ml/kg in hydrogen groups intraperitoneally. Malondialdehyde (MDA) and glutathione-S-transferase (GST) levels were measured in both the plasma and tissue samples. Tissue sections were evaluated histopathologically, and the apoptotic index was detected by TUNEL assay. The results were analyzed by Kruskal-Wallis and Pearson chi-square tests using computer software, SPSS Version 20.0 for Windows.

RESULTS

The MDA levels were higher and GST levels were lower in the torsion and detorsion groups when compared to other groups, but the differences were insignificant (P>0.05). The MDA levels were lower and GST levels were higher in the HT and HTD groups compared with the T and TD groups (P>0.05). Follicular injury, edema, vascular congestion, loss of cohesion and apoptotic index were higher in the torsion groups but decreased in the groups that received HRSS.

CONCLUSIONS

According to histopathological and biochemical examinations, HRSS is effective in attenuating ischemia-reperfusion induced ovary injury.

Aliskiren - a promising strategy for ovarian ischemia/reperfusion injury protection in rats via RAAS

The aim of this study was to evaluate the effects of aliskiren, direct renin inhibitor, as an antioxidant and tissue protective agent and evaluate the molecular, biochemical, and histopathological changes in experimental ischemia and ischemia/reperfusion injury in rat ovaries. Forty-eight female rats were randomly divided into eight groups: in Group 1, only sham operation was performed. Group 2 received 100 mg/kg aliskiren and sham operated. In Group 3, 3 h-period of bilateral ovarian ischemia was applied. Group 4 received a 3-h period of ischemia followed by 3 h of reperfusion. Groups 5 and 6 received 50 and 100 mg/kg, respectively, of aliskiren and bilateral ovarian ischemia was applied (after a 3-h period of ischemia, both ovaries were surgically removed). To Groups 7 and 8, 50 and 100 mg/kg of aliskiren were administered, respectively, and the induction of ischemia was performed. At the end of a 3-h period of ischemia, bilateral vascular clips were removed, and 3 h of reperfusion continued. After the experiments, IL-1β, IL-6, TNF-α, and iNOS mRNA expressions and SOD, GSH, MDA, renin, and angiotensin-II levels were determined and histopathological changes were examined in rat ovaries. Aliskiren treatment normalized excessive changes in cytokine and oxidative stress markers in both ischemia and ischemia/reperfusion injury. Histopathologically, treatment with aliskiren ameliorated the development of ischemia and/or ischemia/reperfusion tissue injury. This study concluded that aliskiren treatment is effective in reversing ischemia and/or ischemia/reperfusion induced ovary damage via the improvement of oxidative stress, reduction of inflammation, and suppression of the renin-angiotensin aldosterone system.

Ovarian toxicity in rats caused by methidathion and ameliorating effect of vitamins E and C

We have investigated the effect of subchronic administration of methidathion (MD) on ovary evaluated ameliorating effects of vitamins E and C against MD toxicity. Experimental groups were as follows: control group; a group treated with 5 mg/kg body weight MD (MD group); and a group treated with 5 mg/kg body weight MD plus vitamin E and vitamin C (MD + Vit group). MD and MD + Vit groups were given MD by gavage five days a week for four weeks at a dose level of 5 mg/kg/day by using corn oil as the vehicle. Serum malondialdehyde (MDA: an indicator of lipid peroxidation) concentration, serum activity of cholinesterase (ChE), and ovary histopathology were studied. The level of MDA increased significantly in the MD group compared with the control ( P < 0.005). Serum MDA decreased significantly in the MD + Vit group compared with the MD group ( P < 0.05). The activities of ChE decreased significantly both in the MD and MD + Vit groups compared with the controls ( P < 0.05). However, the decrease in the MD + Vit groups was less than in the MD group; the ChE activity in the MD + Vit group was significantly higher compared with MD group ( P < 0.05). Number of ovarian follicles were significantly lower in the MD group compared to the controls ( P < 0.05). Number of atretic follicles were significantly higher in the MD group than in the controls ( P < 0.05). Follicle counts in MD + Vit group showed that all types of ovarian follicles were significantly higher, and a significant decrease in the number of atretic follicles compared with the MD group ( P < 0.05). In conclusion, subchronic MD administration caused an ovarian damage, in addition, LPO may be one of the molecular mechanisms involved in MD-induced toxicity. Treatment with vitamins E and C after the administration of MD reduced LPO and ovarian damage. Human & Experimental Toxicology (2007) 26, 491—498

Remifentanil protects uterus against ischemia-reperfusion injury in rats

PURPOSE

To investigate the effects of remifentanil as an antioxidant and analyze the histopathologic, biochemical changes in experimental ischemia-reperfusion (I/R) exposed rat uteri.

METHODS

Wistar albino rats were assigned to three groups (n = 7). 2h period of ischemia was followed by 1h of reperfusion in the I/R and the I/R-remifentanil groups. After ischemia, no drug was administered in the sham and I/R groups. In the I/R-remifentanil group, remifentanil infusion (2 μg/kg/min) was started in the ischemia period, and continued until the end of reperfusion. After the ischemic and reperfusion period, the ischemic uterine horns were removed surgically for biochemical and histopathologic examination. Tissue damage scores (endometrial epithelial glandular leukocytosis, degeneration, and endometrial stromal changes) were examined. Malondialdehyde levels and catalase, superoxide dismutase enzyme activities in tissue were measured.

RESULTS

We found significantly lower epithelial leukocytosis and cell degeneration in the I/R-remifentanil group (p<0.05). Remifentanil administration significantly decreased concentrations of malondialdehyde, and increased catalase and superoxide dismutase enzyme activities (p<0.05).

CONCLUSION

Remifentanil appears to protect the uterine tissue against ischemia-reperfusion and can be used safely in uterus transplantation.

N-acetylcysteine leads to greater ovarian protection than enoxaparin sodium in a rat ovarian torsion model

This study evaluated the effects of N-acetylcysteine (NAC) and enoxaparin on ovarian tissue preservation, ovarian reserve and oxidative damage following ovarian torsion/detorsion injury. Rats were divided into four groups (n = 6/group): control; ischaemia/reperfusion (I/R); I/R + NAC; I/R + enoxaparin. Twenty-four hours after detorsion, ovarian tissues were collected for histopathological analysis and measurement of tissue 8-OHdG, GSH, MDA, MPO and SOD concentrations, as well as pre- and post-operative circulating AMH concentrations. Administration of NAC resulted in more pre-antral follicles compared with enoxaparin treatment and haemorrhage and follicle cell degeneration were more pronounced in I/R + enoxaparin group than I/R + NAC group. Both NAC and enoxaparin led to a significant reduction in ovarian tissue 8-OHdG (P = 0.004 and P = 0.01, respectively) and MPO (P = 0.013 and P = 0.023, respectively) concentrations compared with I/R group, indicating a protective effect against I/R oxidative damage. Only NAC-treated animals showed a significant increase in GSH and SOD concentrations and decrease in MDA concentrations compared with I/R group (P = 0.007, P = 0.024 and P = 0.026, respectively). These results indicate that NAC is more effective than enoxaparin in minimizing ovarian damage and preserving ovarian reserve following ovarian torsion.

Oxidative Stress during Ovarian Torsion in Pediatric and Adolescent Patients: Changing The Perspective of The Disease

Among the different causes of gynecological acute pelvic pain, ovarian torsion represents a surgical emergency. It is a rare case in the pediatric/adolescent aged group that must be included in the differential diagnosis of any girl with abdominal pain or pelvic/abdominal mass. Current recommendations suggest that laparoscopic detorsion should be performed in order to preserve the integrity of the ovaries and fertility, although oophoropexy may be considered in case of severe necrosis. Nevertheless, maintaining the circulation of the ovary after detorsion deteriorates the tissue injury and leads to a pathologic process called ischaemia/reperfusion (I/R) injury, which is characterized by oxidative stress. During the detorsion process, an excess amount of molecular oxygen is supplied to the tissues, and reactive species of oxygen (ROS) such as superoxide radical (O₂^-), hydrogen peroxide (H₂O₂), hydroxyl radical (OH•), as well as reactive nitrogen species (RNS) are produced in excess. ROS, RNS and their toxic products cause DNA damage and lipid peroxidation in the cellular and mitochondrial membranes, leading to cell death. In spite of attention on this topic, currently there is no shared and clear evidence about the use of anti-inflammatory and antioxidant agents to prevent I/R damage after laparoscopic ovarian detorsion. Considering this element, future research should aim to develop shared protocols for the clinical use (route of application, dosage and time of application) of antioxidants after laparoscopic management of this condition.

Ascorbic acid prolongs the viability and stability of isolated perfused lungs: A mechanistic study using 31P and hyperpolarized 13C nuclear magnetic resonance

Ex vivo lung perfusion (EVLP) has recently shown promise as a means of more accurately gauging the health of lung grafts and improving graft performance post-transplant. However, reperfusion of ischemic lung promotes the depletion of high-energy compounds and a progressive loss of normal mitochondrial function, and it remains unclear how and to what extent the EVLP approach contributes to this metabolic decline. Although ascorbate has been used to mitigate the effects of ischemia-reperfusion injury, the nature of its effects during EVLP are also not clear. To address these uncertainties, this study monitored the energy status of lungs during EVLP and after the administration of ascorbate using (31)P and hyperpolarized (13)C NMR (nuclear magnetic resonance). Our experiments demonstrated that the oxidative phosphorylation capacity and pyruvate dehydrogenase flux of lungs decline during ex vivo perfusion. The addition of ascorbate to the perfusate prolonged lung viability by 80% and increased the hyperpolarized (13)C bicarbonate signal by a factor of 2.7. The effect of ascorbate is apparently due not to its antioxidant quality but rather to its ability to energize cellular respiration given that it increased the lung's energy charge significantly, whereas other antioxidants (glutathione and α-lipoic acid) did not alter energy metabolism. During ascorbate administration, inhibition of mitochondrial complex I with rotenone depressed energy charge and shifted the metabolic state of the lung toward glycolysis; reenergizing the electron transport chain with TMPD (N,N,N',N'-tetramethyl-p-phenylenediamine) recovered metabolic activity. This indicates that ascorbate slows the decline of the ex vivo perfused lung's mitochondrial activity through an independent interaction with the electron transport chain complexes.

Protective Effect of Platelet Rich Plasma on Experimental Ischemia/Reperfusion Injury in Rat Ovary

BACKGROUND/AIMS

Ovarian torsion is a common cause of local ischemic damage, reduced follicular activity and infertility. Platelet-rich plasma (PRP) contains growth factors with demonstrated cytoprotective properties; so we evaluated PRP efficacy in a rat ischemia/reperfusion (I/R) model.

METHODS

Sixty adult female Sprague-Dawley albino rats were randomly assigned to 6 groups of 8 animals each: Sham, Ischemia, I/R, Sham + PRP, I + PRP and I/R + PRP; and the remaining 12 used to prepare PRP. Ischemia groups were subjected to bilateral adnexal torsion for 3 h, while I/R and I/R + PRP groups received subsequent detorsion for 3 h. Intraperitoneal PRP was administered 30 min prior to ischemia (Ischemia + PRP) or reperfusion (I/R + PRP).

RESULTS

Total oxidant status (TOS), oxidative stress index (OSI) and total ovarian histopathological scores were higher in Ischemia and I/R groups than in the Sham group (p < 0.05). PRP decreased mean TOS, OSI and histopathological scores in I + PRP and I/R + PRP groups compared to the corresponding Ischemia and I/R groups (p < 0.001). There was a strong correlation between total histopathological score and OSI (r = 0.877, p < 0.001). Peritoneal vascular endothelial growth factor was significantly higher in PRP-treated groups than corresponding untreated groups (p < 0.05).

CONCLUSION

PRP is effective for the prevention of ischemia and reperfusion damage in rat ovary.

The effect of hypothermia on adnexal torsion/detorsion injury in a rat ovary model

PURPOSE

Much attention has been given to hypothermia as it is effective in inhibiting inflammatory responses and also ischemia/reperfusion injury. Therefore, the aim of this study was to evaluate the effect of hypothermia on torsion/detorsion injury in rats.

METHODS

Twenty-eight rats were randomly divided into four groups of sham-operated (SG), adnexal torsion/detorsion group (TG), adnexal torsion/detorsion+hypothermia group (THG) and hypothermia group (HG). In the SG group, right ovaries were excised after 3-h fixation to abdominal wall. In the TG, right adnexal underwent 720° torsion in a counterclockwise direction for 3h and then excised after 3-h detorsion period. In the THG, after 3-h torsion period, ovaries were immediately subjected to hypothermia (4°C) for 30-min and they were excised after 3-h detorsioned period. In the HG, the right ovaries were subjected to hypothermia for 30-min and excised after 3-h fixation period. One half of each ovary was immediately stored for antioxidant enzyme activity and tissue lipid peroxidation. The remainder was fixed for histopathological examination.

RESULTS

Adnexal torsion and detorsion significantly increased the tissue level of Malondialdehyde, Superoxide dismutase and Reduced glutathione. On the other hand, hypothermia significantly reduced these oxidative stress parameters. The histopathological changes were less in the THG group; these changes were not statistically different from the other groups.

CONCLUSION

The results of this study suggested that hypothermia inhibited the production of oxidative stress in the ovaries subjected to torsion/detorsion injury.

Effects of L-carnitine on follicular survival and graft function following autotransplantation of cryopreserved-thawed ovarian tissues

The aim of this study was to investigate the effects of L-carnitine (LC) on follicular survival and ovarian function following cryopreservation-thawing and autotransplantation of ovarian tissues. ICR mice were divided into three groups: control; saline group (cryopreservation+autograft+saline); and LC group (cryopreservation+autograft+L-carnitine). The ovarian tissues from control group, saline group, and LC group were histological assessed. There were no significant differences in the percentage of morphologically normal primordial follicles between the LC group and the saline group. After 28 days of autotransplantation, apoptosis rates, plasma malondialdehyde (MDA), progesterone (P4) and estradiol (E2) concentrations, and follicular densities of grafts were evaluated. Apoptosis rate and the concentration of MDA in the LC group were significantly lower than those in the saline group. The concentration of E2 and follicular densities of grafts in LC group were significantly higher than that in saline group. LC inhibits follicle apoptosis and increases follicular survival and function of ovarian graft.

Effect of antifreeze protein on mouse ovarian tissue cryopreservation and transplantation

PURPOSE

To investigate the effect of antifreeze protein (AFP) supplementation on ovarian vitrification and transplantation.

MATERIALS AND METHODS

In this experimental study, we researched a total of 182 ovaries from 4-week-old ICR mice. The equilibration solution included 20% ethylene glycol (EG), and the vitrification solution included 40% EG, 18% Ficoll, and 0.3 M sucrose. Intact ovaries were first suspended in 1 mL of equilibration solution for 10 min, and then mixed with 0.5 mL of vitrification solution for 5 min. Ovaries were randomly assigned to 3 groups and 0, 5, or 20 mg/mL of type III AFP was added into the vitrification solution (control, AFP5, and AFP20 groups, respectively). The vitrified ovaries were evaluated after warming and 2 weeks after autotransplantation. The main outcome measurements are follicular morphology and apoptosis assessed by histology and the TUNEL assay.

RESULTS

A significantly higher intact follicle ratio was shown in the AFP treated groups (control, 28.9%; AFP5, 42.3%; and AFP20, 44.7%). The rate of apoptotic follicles was significantly lower in the AFP treated groups (control, 26.6%; AFP5, 18.7%; and AFP20, 12.6%). After transplantation of the vitrified-warmed ovaries, a significantly higher intact follicle ratio was shown in the AFP20 group. The rate of apoptotic follicles was similar among the groups.

CONCLUSION

The results of the present study suggest that supplementing AFP in the vitrification solution has beneficial effects on the survival of ovarian tissue during cryopreservation and transplantation.

Effect of detorsion alone and in combination with enoxaparin therapy on ovarian reserve and serum antimüllerian hormone levels in a rat ovarian torsion model

OBJECTIVE

To investigate the effect of enoxaparin on ovarian reserve and serum antimüllerian hormone (AMH) levels in a rat ovarian torsion model.

DESIGN

Experimental study.

SETTING

Experimental surgery laboratory in a training and research hospital.

ANIMAL(S)

Fourteen female Wistar Hannover rats.

INTERVENTION(S)

1) Control group received no special treatment other than abdominal exposure; 2) detorsion-only group received bilateral adnexal torsion (3-hour ischemia), and then after 3-hour torsion period, detorsion (reperfusion) was performed; and 3) detorsion-enoxaparin group received 0.5 mg/kg enoxaparin subcutaneously 2 hours before the same surgery as the detorsion-only group and a second 0.5 mg/kg dose of enoxaparin 24 hours after the first surgeries. Apart from the surgeries, preoperative and postoperative 1-mL blood samples were drawn from the right jugular vein of each rat.

MAIN OUTCOME MEASURE(S)

Preoperative and postoperative serum AMH levels, histopathologic damage scores, and follicle counts in the ovarian tissue of the rats.

RESULT(S)

Vascular congestion and hemorrhage scores were higher in the detorsion-enoxaparin group than in the detorsion-only and control groups. The number of small antral follicles was smaller in the detorsion-only group than in the control group. The difference in the pre- and postoperative AMH levels was higher in the detorsion-only group than in the control and detorsion-enoxaparin groups.

CONCLUSION(S)

The combination of enoxaparin therapy with conventional ovarian detorsion is more effective in protecting the ovarian reserve than detorsion alone.

Effect of necrostatin on mouse ovarian cryopreservation and transplantation

OBJECTIVE

To investigate the effects of necrostatin-1 (Nec-1) supplementation on vitrification, warming and transplantation of ovarian tissue.

STUDY DESIGN

Ovaries from 4-week-old ICR mice were vitrified using a two-step procedure; ovaries were suspended in equilibration solution for 10min, and then mixed with vitrification solution for 5min. Ovaries were divided at random into three groups and 0 (control), 25 or 100μM Nec-1 was added to the vitrification solution. After warming, follicular morphology and apoptosis were assessed. For each group, a sample of vitrified, warmed ovaries was autotransplanted. The same dose of Nec-1 that was added to the vitrification solution was added to each warming solution and injected intraperitoneally. Follicular morphology and apoptosis of transplanted ovaries were assessed after 2 weeks.

RESULTS

After vitrification and warming, morphological analysis revealed that the intact follicle ratio was significantly higher in the Nec-1-treated groups compared with the control group (control, 45.1%; 25μM Nec-1, 51.7%; 100μM Nec-1, 57.9%). The rate of apoptosis was lower in the Nec-1 treated groups compared with the control group (control, 11.2%; 25μM Nec-1, 8.5%; 100μM Nec-1, 7.2%). After transplantation of the vitrified, warmed ovaries, morphological analysis revealed that the intact follicle ratio was significantly higher in the Nec-1 treated groups compared with the control group (control, 43.1%; 25μM Nec-1, 60.6%; 100μM Nec-1, 70.7%). The rate of apoptosis was lower in the Nec-1 treated groups compared with the control group (control, 5.3%; 25μM Nec-1, 2.5%; 100μM Nec-1, 2.0%).

CONCLUSIONS

Nec-1 supplementation during vitrification, warming and transplantation has beneficial effects on the survival of ovarian tissue. These results can help to improve ovarian tissue vitrification and transplantation protocols for fertility preservation.

Folicular reserve changes in torsion-detorsion of the ovary: an experimental study

OBJECTIVE

We assess follicular reserve changes by follicle count in torsion-detorsion rat model.

STUDY DESIGN

30 albino rats were randomly divided into 3 groups: sham group (SG), detorsion after 24-hour torsion group (24hTG) and detorsion after 72-hour torsion group (72hTG). Ovaries were torsioned and fixed. They were untwisted 24 and 72 h later. Oophorectomies were performed at 14th day after detorsion. Tissue damage scoring and follicle counts were evaluated microscopically.

RESULTS

Tissue damage scores (TDSs) were higher in 72hTG and 24hTG compared to SG. In addition, as we increase torsion duration, TDSs also increased. There was no statistically significant difference in follicle numbers (primordial, primary, secondary and tertiary).

CONCLUSION

Duration of torsion and intensity of ovarian damage do not affect follicular reserve in a rat model. Regardless of their macroscopic appearance, ovaries maintain their follicle reserves after torsion. Thus, surgeons should be reassured and encouraged to untwist torsioned ovaries rather than removing them.

Combination of a GnRH agonist with an antagonist prevents flare-up effects and protects primordial ovarian follicles in the rat ovary from cisplatin-induced toxicity: a controlled experimental animal study

BACKGROUND

With the continuous improvement of surgery and chemotherapeutic treatments, many tumour patients increasingly achieve long-term survival and can even be completely cured. However, platinum-containing drugs, which are widely used to treat a variety of types of cancer, cause menstrual disorders and ovarian failure, which in turn lead to infertility. Thus far, gonadotropin releasing hormone (GnRH) agonist (GnRHa) and antagonist (GnRHant) are reported to act as protective agents of the ovary in chemotherapy through the inhibition of the female gonadal axis. Nevertheless, they both have disadvantages that limit their use. GnRHa causes a flare-up effect during the first week after administration, and no long-acting GnRHant agent is available. GnRHa combined with GnRHant may prevent the flare-up effect of GnRHa and rapidly inhibit the female gonadal axis. Several clinical studies with small sample sizes have reported controversial conclusions. In this strictly controlled animal study, we investigated the advantages of combination treatment with GnRHa and GnRHant.

METHODS

Rats aged 12 weeks were divided into six groups: Control, cisplatin (CDDP), GnRHa, GnRHant, Combination (sht, short-term) and Combination (lng, long-term) of GnRHa and GnRHant. The last four groups received Triptorelin (1 mg/kg·d, for 14 days), Cetrorelix (0.5 mg/kg·d, for 10 days), a combination of Triptorelin (1 mg/kg·d, for 10 days) and Cetrorelix (0.5 mg/kg·d, for 10 days) in the long-term group and for 3 days in the short-term group. The Control and CDDP groups received saline (1 ml/kg·d, for 10 day). Then, all groups apart from the Control group received cisplatin (1 mg/kg·d, for 10 days), and the Control group received another 10 days of saline as described above. Blood samples were collected to detect the serum levels of E2, LH and FSH. Observation of oestrous cyclicity was also performed after drug administration. Finally, bilateral ovaries were collected for histological study and follicle counting.

RESULTS

We observed a flare-up effect in rats treated with GnRHa, but not in any of the combination groups. The percentage of normal cyclicity increased from 0% in the CDDP group to 25.0%, 33.3%, 66.7% and 41.7%, in the GnRHa, GnRHant, combination (lng) and combination (sht) groups, respectively. Pretreatment with GnRHa, GnRHant and combination (lng) significantly protected the primordial follicles from destruction by preserving 57.6%, 63.4%, 87.1% and 60.4% of the follicles, respectively.

CONCLUSIONS

The combination of a GnRH agonist with antagonist completely prevented the flare-up effect and enhanced the protective effect of the ovary from cisplatin-induced gonadotoxicity in rats.

Selenium has a protective effect on ischemia/reperfusion injury in a rat ovary model: biochemical and histopathologic evaluation

BACKGROUND/PURPOSE

The aim of the study was to evaluate the effects of selenium (Se) on ischemia/reperfusion (I/R) injury in rat ovaries.

METHODS

Thirty-five female Sprague-Dawley rats were randomly divided into 5 groups (n = 7): sham (S), I/R1, I/R2, Se1, and Se2. In the I/R1 and Se1 groups, 4 hours of ischemia was followed by 6 hours of reperfusion, and in the I/R2 and Se2 groups, 4 hours of ischemia was followed by 12 hours of reperfusion. In the Se groups, 30 minutes before reperfusion, a single dose of 0.2 mg/kg Se was administered intraperitoneally. The ovarian tissue levels of malondialdehyde (MDA) and nitric oxide (NO), and the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were measured biochemically. Tissue damage to ovarian tissue was scored by histopathologic examination.

RESULTS

The I/R groups had significantly higher MDA levels and lower CAT, SOD, and GPx activities than the sham group (P < .05). Although NO levels were significantly higher in the I/R1 group than in the sham group (P < .05), the NO levels in the I/R2 and sham groups were similar. Selenium pretreatment significantly lowered tissue MDA and NO levels and increased tissue SOD and GPx activities in the Se groups, compared with those in the I/R groups (P < .05). Catalase activities were significantly higher in the Se2 group than in the I/R2 group (P < .05). Catalase activities were higher in the Se1 group than in the I/R1 group, but the difference was not statistically significant. Treatment with Se significantly decreased the ovarian tissue damage scores in the Se2 group compared with those in the I/R2 group (P < .05).

CONCLUSION

Selenium is effective in preventing tissue damage induced by I/R in rat ovaries.

Effects of co-administration of dopamine and vitamin C on ischaemia-reperfusion injury after experimental testicular torsion-detorsion in rats

The objective of this study was to investigate the effects of dopamine as vasodilator, vitamin C as an antioxidant and combined administration of them on ischaemia-reperfusion (I-R) injury following testicular torsion (TT). Thirty adult male rats were divided into six groups each containing five rats. Testicular ischaemia was achieved by twisting the left testis for 4 h. Group 1 was for determination of the basal values. Group 2 had 4 h TT. Group 3 had 4 h TT and was then treated with dopamine. Group 4 had 4 h TT and was then treated with vitamin C. Group 5 had 4 h TT and was then treated with dopamine and vitamin C. Group 6 was designed as a sham operated group. Testicular torsion caused a significant decrease in the percentage of spermatogenesis and seminiferous tubules diameters compared with the control and sham groups. Administration of dopamine, vitamin C and their combination increased above mentioned parameters and decreased serum malondialehyde levels significantly. However, vitamin C had better results than the other treatments (P < 0.05). In conclusion, a potent antioxidant like vitamin C was found to be more effective than increasing blood flow by a vasodilator like dopamine on improving I-R injury following TT.

Protective effect of tadalafil on ischemia/reperfusion injury of rat ovary

BACKGROUND/PURPOSE

The aim of the study was to evaluate the effects of tadalafil (TDF) on ischemia/reperfusion (I/R) injury in rat ovaries.

METHODS

Thirty-five female Sprague-Dawley rats were randomly divided into 5 groups (n = 7): sham (S), I/R1, I/R2, TDF1, and TDF2. In the I/R1 and TDF1 groups, 3-hour ischemia was followed by 12-hour reperfusion; and in the I/R2 and TDF2 groups, 3-hour ischemia was followed by 24-hour reperfusion. In the TDF groups, 30 minutes before reperfusion, a single dose of 5 mg/kg TDF was administered intraperitoneally. The ovarian tissue levels of malondialdehyde and nitric oxide (NO), and the activities of superoxide dismutase and catalase were measured biochemically. Tissue damage to ovarian tissue was scored by histopathologic examination.

RESULTS

The tissue malondialdehyde levels were significantly higher and the catalase and superoxide dismutase activities were significantly lower in the I/R groups compared with the S and TDF groups (P < .05). The NO levels were significantly higher in the TDF1 group than the S and I/R1 groups (P < .05). Although the NO levels were increased in the TDF2 group compared with the I/R2 group, the difference was not significant. Ovarian tissue damage scores of the I/R groups were significantly higher than those of the S group (P < .05). Treatment with TDF significantly decreased the ovarian tissue damage scores in the TDF groups compared with the I/R groups (P < .05).

CONCLUSIONS

Tadalafil is effective in preventing tissue damage induced by I/R in rat ovaries.

Protective effect of erythropoietin on torsion/detorsion injury in rat model

PURPOSE

The aim of the study is to investigate the effects of erythropoietin on torsion/detorsion injury in rats.

METHODS

Forty rats were divided randomly into 5 groups: group I (sham, S), sham operation; group II (torsion/detorsion 1, T/D(1)), 3 hours ischemia and 1 hour reperfusion; group III (torsion/detorsion 2, T/D(2)), 3 hours ischemia and 48 hours reperfusion; group IV (erythropoietin 1, EPO(1)), 3 hours ischemia, 1 hour reperfusion, and a single dose of EPO; and group V (erythropoietin 2, EPO(2)), 3 hours ischemia, 48 hours reperfusion, and 2 doses of EPO. Malondialdehyde (MDA) and nitric oxide (NO) levels and activities of superoxide dismutase and catalase were measured. Tissue damage to ovarian tissue was scored by histologic examination. Data were compared among groups with parametric tests.

RESULTS

The MDA levels in the S and EPO groups were significantly lower than the T/D groups (P < .001). Catalase and superoxide dismutase activities, and NO levels in the S and EPO groups were significantly higher than in the T/D groups (P < .05). Ovarian tissue damage in the S and EPO groups was significantly less than in the T/D groups (P < .05). Levels of all biochemical markers and ovarian tissue damage scores were similar among the S, EPO(1), and EPO(2) groups (P > .05).

CONCLUSION

Erythropoietin attenuates ischemia-reperfusion injury when given during the acute phase of ovarian torsion-detorsion in a rat model.

Critical ischemic time for the rat ovary: experimental study evaluating early histopathologic changes

The aim of the present study was to determine a critical ischemic time for ovary in an experimental study in rats. An experimental model using slip-knot tying of all ovarian arteries and veins in cycling female rats was developed. Rat ovaries were tied using the technique through an explorative laparotomy. Complete ischemia times of 1, 2 and 3 h were used for the study. At the end of the ischemic times, the ovaries were harvested following 1 h of reperfusion. Histology indicated a gradually increased congestion correlating with the respective increased ischemic times. According to the present findings 2 h complete ischemia yields a significant injury. The model used in the present study may be used for complete ischemia-reperfusion injury of the rat ovary.