The Effects of Dexmedetomidine on Abdominal Aortic Occlusion-Induced Ovarian Injury via Oxidative Stress and Apoptosis

Ischemia/reperfusion (I/R) induced ovarian damage is caused by various diseases such as ovarian torsion, ovarian transplantation, cardiovascular surgery, sepsis, or intra-abdominal surgery. I/R-related oxidative damage can impair ovarian functions, from oocyte maturation to fertilization. This study investigated the effects of dexmedetomidine (DEX), which has been shown to exhibit antiapoptotic, anti-inflammatory, and antioxidant effects, on ovarian I/R injury. We designed four study groups: group 1 (n = 6): control group; group 2 (n = 6): only DEX group; group 3 (n = 6): I/R group; group 4 (n = 6): I/R + DEX group. Then, ovarian samples were taken and examined histologically and immunohistochemically, and tissue malondialdehyde (MDA) and glutathione (GSH) levels were measured. In the I/R group MDA levels, caspase-3, NF-κB/p65, 8-OHdG positivity, and follicular degeneration, edema, and inflammation were increased compared to the control group (p = 0.000). In addition, GSH levels were significantly decreased in the I/R group compared to the control group (p = 0.000). On the other hand, in the I/R + DEX treatment group MDA levels, caspase-3, NF-κB/p65, 8-OHdG positivity, follicular degeneration, edema, and inflammation findings were decreased than in the I/R group (p = 0.000, p = 0.005, p = 0.005, p = 0.001, p = 0.005, respectively). However, GSH levels increased significantly in the I/R + DEX treatment group compared to the I/R group (p = 0.000). DEX protects against ovarian I/R injury through antioxidation and by suppressing inflammation and apoptosis.

An investigation of the effects of metformin on ovarian ischemia-reperfusion injury in rats

Damage to the ovaries or tissue torsion can significantly reduce the ovarian reserve and thus cause severe gynecological and hormonal deficiencies. The discovery of new agents is always needed in the treatment of this condition. Metformin (MET) has been shown to be beneficial in attenuating ovarian ischemia-reperfusion injury. Fifty-six female Sprague Dawley rats were divided into seven groups. Group 1 represented the control group (C), Group 2, the ischemia group (I), and Group 3, the ischemia/reperfusion group (I/R). Group 4, the ischemia (I)+250 group, and Group 5, the ischemia (I)+500 group, received 250 mg/kg and 500 mg/kg MET, respectively. Group 6, the ischemia/reperfusion (I/R)+250 group, and Group 7, the ischemia/reperfusion (I/R)+500 group, received 250 mg/kg and 500 mg/kg MET, respectively. Tissue malondialdehyde (MDA), glutathione (GSH), and tumor necrosis factor-alpha (TNF-α) levels in ovarian tissue increased following I/R, while estradiol (E₂) levels decreased. Moreover, infiltration and diffuse edematous areas were observed in addition to diffuse vascular congestion and hemorrhage findings. Caspase-3 and nuclear factor kappa B (NF-κβ) expression levels also increased. MDA and TNF-α concentrations decreased in the MET treatment groups, while GSH and E₂ levels increased. The findings showed that I/R causes ovarian damage through the induction of oxidative stress, inflammation, and apoptosis. However, MET application was effective in preventing damage in ovarian tissue by reducing levels of reactive oxygen species, proinflammatory cytokines, caspase-3 and NF-κβ.

The investigation of therapeutic potential of oxytocin and liraglutide on vincristine-induced neuropathy in rats

The aim of this study was to assess the therapeutic potential of oxytocin and liraglutide (LIR), a GLP-1 analogue, in a rat model of vincristine-induced neuropathy. Rats were injected with vincristine (VCR) at a dose of 4 mg/kg twice a week for 5 weeks. The VCR-administered rats were divided into three groups and received saline, oxytocin, or liraglutide simultaneously with VCR. After the treatment period, electrophysiological, biochemical, histological, and immunohistochemical investigations were performed. Electromyography (EMG) recordings demonstrated significant alterations in the VCR + saline group (p < .001). Also, motor performance was decreased in the VCR + saline group (p < .05). Histologically, the axonal diameter was decreased in all groups. VCR + saline group showed significantly increased lipid peroxidation and decreased nerve growth factor (NGF) expression. However, the administration of oxytocin and liraglutide significantly prevented the EMG alterations, lipid peroxidation, and reduction in neuronal NGF expression. On the basis of these findings, oxytocin and liraglutide may be considered as potential agents for the prevention of VCR-induced neuropathy.

The effect of oxytocin and Kisspeptin-10 in ovary and uterus of ischemia-reperfusion injured rats

OBJECTIVE

Ischemia/reperfusion (I/R) injuries result in damage to endothelial and parenchymal cells. Oxytocin (OXY) stimulates uterine contraction during parturition and myoepithelial cells during suckling. OXY has been used as a protective antioxidant. Kisspeptin plays a key role in the central control of reproductive functions and onset of puberty. Recent studies show that these reproductive hormones have protective potential as antioxidant. The aim of this study is to investigate the potential protective effects of Kisspeptin and OXY as antioxidants on I/R injured ovary and uterus of female rats.

MATERIALS AND METHODS

Rats were separated into five groups. Group 1, is control group; Group 2, rats were subjected to ischemia followed by reperfusion. Group 3, OXY administration 30 min prior to I/R applied rats; Group 4, Kisspeptin administration 30 min prior to I/R applied rats; Group 5, OXY and Kisspeptin administration 30 min prior to I/R. Ovary and uterus were removed for histopathological and biochemical observations. Malondialdehyde, glutathione levels, and superoxide dismutase activities were analyzed in order to observe antioxidant potential of OXY and Kisspeptin. Hematoxylin and Eosin staining was applied for histopathologic scoring.

RESULTS

Stromal and granulosa cells in ovary, endometrial cells in uterus were damaged in I/R group. The cellular damage of ovary and uterus were reduced in OXY and Kisspeptin administered I/R group when compared to only Kisspeptin injected I/R group and I/R group. There is no significant difference between OXY and OXY + Kisspeptin injected I/R groups. MDA levels were decreased in Kisspeptin and/or Oxytocin applied I/R group compared to I/R group. SOD activity and GSH levels were increased in Kisspeptin and/or OXY applied I/R group compared to I/R group.

CONCLUSIONS

The present results suggest that exogenous application of oxytocin and kisspeptin can have antioxidant effects on the uterus and ovary.

Effects of carvedilol on an ischemia/reperfusion model: Biochemical, histopathological and immunohistochemical evaluation

AIM

The aim of this study was to investigate the effects of carvedilol (CVD) on experimentally induced ovarian ischemia/reperfusion (I/R) injury in rats.

METHODS

An ovarian I/R model was applied to rats, classified into three groups: 1 (n = 7), sham operated (control); 2 (n = 7), 3 h ischemia + 3 h reperfusion (I/R); 3 (n = 7), 3 h ischemia + CVD + 3 h reperfusion (I/R + CVD). Malondialdehyde (MDA) levels and glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities in ovarian tissues and serum were measured. Tissue damage was examined histopathologically; Bax and caspase-3 expression was determined immunhistochemically. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to show apoptotic cell death.

RESULTS

MDA levels in ovarian tissues were significantly increased in the I/R group compared with the control. CVD administration significantly decreased tissue MDA levels in the I/R + CVD in comparison with the I/R group. GSH-Px activities in serum were higher in the I/R + CVD than in the I/R group. SOD activities in tissue and serum were significantly decreased in the I/R compared with the control group. Histological examination showed a significant improvement in ovarian morphology in the I/R + CVD compared with the I/R group. Bax and caspase-3 protein was more strongly expressed in the I/R group compared with the control and I/R + CVD groups. Apoptotic index detected by TUNEL assay was significantly increased in the I/R and decreased in the I/R + CVD group.

CONCLUSION

Our results suggest that CVD reduces the deleterious effects of oxidative damage on ovaries in a rat I/R model.

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.

Edaravone mitigates hexavalent chromium-induced oxidative stress and depletion of antioxidant enzymes while estrogen restores antioxidant enzymes in the rat ovary in F1 offspring

Environmental contamination of drinking water with chromium (Cr) has been increasing in more than 30 cities in the United States. Previous studies from our group have shown that Cr affects reproductive functions in female Sprague Dawley rats. Although it is impossible to completely remove Cr from the drinking water, it is imperative to develop effective intervention strategies to inhibit Cr-induced deleterious health effects. Edaravone (EDA), a potential inhibitor of free radicals, has been clinically used to treat cancer and cardiac ischemia. This study evaluated the efficacy of EDA against Cr-induced ovarian toxicity. Results showed that maternal exposure to CrVI in rats increased follicular atresia, decreased steroidogenesis, and delayed puberty in F1 offspring. CrVI increased oxidative stress and decreased antioxidant (AOX) enzyme levels in the ovary. CrVI increased follicle atresia by increased expression of cleaved caspase 3, and decreased expression of Bcl2 and Bcl2l1 in the ovary. EDA mitigated or inhibited the effects of CrVI on follicle atresia, pubertal onset, steroid hormone levels, and AOX enzyme activity, as well as the expression of Bcl2 and Bcl2l1 in the ovary. In a second study, CrVI treatment was withdrawn, and F1 rats were injected with estradiol (E₂) (10 μg in PBS/ethanol per 100 g body weight) for a period of 2 wk to evaluate whether E₂ treatment will restore Cr-induced depletion of AOX enzymes. E₂ restored CrVI-induced depletion of glutathione peroxidase 1, catalase, thioredoxin 2, and peroxiredoxin 3 in the ovary. This is the first study to demonstrate the protective effects of EDA against any toxicant in the ovary.

Protective effect of oxytocin on ovarian ischemia-reperfusion injury in rats

Oxytocin (OT), a neurohypophysial nonapeptide, plays dual role as a neurotransmitter/neuromodulator and a hormone. It has also well known protective properties against ischemia/reperfusion organ damage. This study investigated the effect of OT on experimentally induced ovarian torsion/de-torsion ischemia/reperfusion (I/R) injury in rats. Sprague-Dawley rats were assigned to five treatment groups (n=7/group): Group 1, sham-operated; Group 2, torsion; Group 3, 80 IU/kg of OT administration 30 min prior to torsion; Group 4, torsion/de-torsion; and Group 5, torsion followed by 80 IU/kg of OT administration 30 min prior to de-torsion. OT administration significantly decreased the tissue malondialdehyde (MDA) levels in both the torsion and OT group (Group 3), and torsion/de-torsion OT group (Group 5) in comparison with the torsion-only group (Group 2) and torsion/de-torsion group (Group 4). Histopathological finding scores including follicular degeneration, edema, hemorrhage, vascular congestion, and infiltration by inflammatory cells were found to be significantly decreased in the torsion and OT group (Group 3), and torsion/de-torsion OT group (Group 5) when compared with the torsion-only group (Group 2) and torsion/de-torsion group (Group 4). In conclusion, these results, verified with histopathologic evaluation and biochemical assays, suggest a probable protective role for OT in ischemia and I/R injury in rat ovaries.