The effects of iloprost, a prostacyclin analogue, in experimental ischaemia/reperfusion injury in rat ovaries

Artemisinin reduces acute ovarian ischemia-reperfusion injury in rats

Artemisinin (ARS) is well known as an effective agent in the treatment of malaria through the rapid elimination of Plasmodium falciparum parasites. This study aims to investigate the effect of ARS in treating adnexal torsion, one of the most common gynecological surgical emergencies. ARS was administered intraperitoneally once 30 min before unilateral ovarian torsion in two different doses (10 mg/kg vs. 50 mg/kg). Torsion was maintained for 3 h and then held in the detorted state for 3 h. Bilateral adnexectomy was performed to measure antioxidant enzyme activities and oxidant levels on the ipsilateral ovary and to make histopathological and immunohistochemical analyses on the contralateral ovary. Ischemia-reperfusion (I/R) injury dramatically upregulated the activities of CAT, GST, and MDA levels in the ipsilateral ovary, which were all downregulated by ARS treatment. A significant increase in follicular cell degeneration, congestion, and edema in the contralateral ovary was seen in the I/R group, which was significantly reduced with ARS treatment. Furthermore, I/R injury resulted in a significant increase in apoptosis as shown by the increased levels of BAX and CASP-3, and decreased levels of BCL-2 whereas ARS significantly reduced the impact of the injury. Our data, based on a rat I/R injury model, show that both ipsilateral and contralateral ovaries are protected with ARS pretreatment, and 50 mg/kg ARS treatment demonstrates to be more effective than the 10 mg/kg ARS.

Treprostinil, a prostacyclin analog, ameliorates renal ischemia-reperfusion injury: preclinical studies in a rat model of acute kidney injury

BACKGROUND

Renal ischemia-reperfusion injury (IRI) is a major factor causing acute kidney injury (AKI). No pharmacological treatments for prevention or amelioration of I/R-induced renal injury are available. Here we investigate the protective effects of treprostinil, a prostacyclin analog, against renal IRI in vivo.

METHODS

Male Sprague Dawley rats were subjected to bilateral renal ischemia (45 min) followed by reperfusion for 1-168 h. Treprostinil (100 ng/kg/min) or placebo was administered subcutaneously for 18-24 h before ischemia.

RESULTS

Treatment with treprostinil both significantly reduced peak elevation and accelerated the return to baseline levels for serum creatinine and blood urea nitrogen versus I/R-placebo animals following IRI. I/R-treprostinil animals exhibited reduced histopathological features of tubular epithelial injury versus I/R-placebo animals. IRI resulted in a marked induction of messenger RNA coding for kidney injury biomarkers, kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin and for pro-inflammatory cytokines chemokine (C-C motif) ligand 2, interleukin 1β, interleukin 6 and intracellular adhesion molecular 1 in animals treated with placebo only relative to sham controls. Upregulation of expression of all these genes was significantly suppressed by treprostinil. Treprostinil significantly suppressed the elevation in renal lipid peroxidation found in the I/R-placebo group at 1-h post-reperfusion. In addition, renal protein expression of cleaved poly(ADP-ribose) polymerase 1 and caspase-3, -8 and -9 in I/R-placebo animals was significantly inhibited by treprostinil.

CONCLUSIONS

This study demonstrates the efficacy of treprostinil in ameliorating I/R-induced AKI in rats by significantly improving renal function early post-reperfusion and by inhibiting renal inflammation and tubular epithelial apoptosis. Importantly, these data suggest that treprostinil has the potential to serve as a therapeutic agent to protect the kidney against IRI in vivo.

[Current antiplatelet agents, new inhibitors and therapeutic targets]

Cardiovascular diseases are the leading cause of deaths in the world. Platelets play a major role in the occurrence of these diseases and the development of antiplatelet drugs is a priority in the fight against cardiovascular diseases-associated mortality. Aspirin and thienopyridine-based P2Y12 inhibitors are the main drugs currently used. These molecules target the initiation of platelets activation and are responsible for a moderate inhibitory action. Other antiplatelet agents, as glycoprotein (GP) IIb/IIIa antagonists, inhibit platelet aggregation independently of initial activation-associated pathways, but are responsible for increased hemorrhagic events. Regarding each antiplatelet agent's specific characteristics, the prescription of these drugs must take into account the type of cardiovascular event, the age of the patient, the past medical history, and the potential hemorrhagic adverse events. Thus, there is a need for the development of new molecules with a more targeted effect, maintaining optimal efficiency but with a reduction of the hemorrhagic risk, which is the principal limitation of these treatments.

Effects of iloprost on experimental ischemia and reperfusion injury in rat ovary

We investigated the protective effect of iloprost against ischemia/reperfusion (I/R) injury in rat ovary. We used 32 female Sprague-Dawley rats randomly allocated to four experimental groups: sham, ischemia, I/R and I/R + iloprost. Ovarian torsion was established in all rats except the sham group. The torsion group was exposed to ischemia for 3 h. The detorsion group was exposed to 3 h ischemia applied + 3 h reperfusion. The detorsion + iloprost group was exposed to ischemia for 3 h + reperfusion for 3 h + intravenous (IV) iloprost infusion for 60 min starting at the beginning of reperfusion. Ovaries were removed and prepared for histopathological evaluation. Reduced glutathione (GSH) and malondialdehyde (MDA) were measured in the blood. The total histopathological injury score and MDA level of the ischemia group were significantly higher than for the sham group. Ovarian injury score and MDA level following I/R increased compared to the ischemia group. Iloprost administration reduced the total injury score and MDA level. The GSH level was higher in the I/R + iloprost group than in the I/R group. We concluded that IV iloprost administration reduces I/R injury in rat ovarian tissue.

Protective effects of tempol in an experimental ovarian ischemia-reperfusion injury model in female Wistar albino rats

The aim of this study was to investigate the antioxidant effects of tempol on ovarian ischemia-reperfusion (I/R) injury in rats. Forty female Wistar albino rats were randomly divided into 5 groups: Group I, sham; Group II, ischemia (I); Group III, I/R; Group IV, I/R + tempol 30 mg/kg i.p; Group V, I/R + tempol 50 mg/kg i.p. Oxidative stress index (OSI) was significantly higher in the ischemia group and the I/R group than in the sham group. Catalase levels were significantly lower in the I/R group than in the I/R + tempol 30 mg/kg i.p. and the I/R + tempol 50 mg/kg i.p. groups. Glutathione peroxidase levels were lower in the I/R group than in the I/R + tempol 30 mg/kg i.p. and the I/R + tempol 50 mg/kg i.p. groups. MDA levels were significantly lower in the I/R + tempol 30 mg/kg i.p. group and the I/R + tempol 50 mg/kg i.p. group than in the I/R group. The levels of the histopathological parameters were significantly decreased in the I/R + tempol 50 mg/kg i.p. group compared with the I/R group. Tempol can be used for reducing ovarian I/R injury.

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.

Dose dependent protective effects of vardenafil on ischemia-reperfusion injury with biochemical and histopathologic evaluation in rat ovary

PURPOSE

The purpose of the study is to evaluate the effect of vardenafil on the histopathology and biochemical parameters in reducing damage in experimental ovarian ischemia and ischemia/reperfusion injury in a rat model and to compare the effect of two different doses of vardenafil.

METHODS

Forty-two rats with experimental ovarian torsion. Group-I: sham; Group-II: ovarian ischemia; Group-III: 2 hours of ischemia followed by a 2-hour reperfusion. Group-IV: two hours before the sham operation, rats received 1mg/kg vardenafil; Group V and VI: A 2-hour period of ovarian ischemia was applied, in which rats were treated with intraperitoneal vardenafil 1 and 2mg/kg dose, after 1.5 hours of ovarian ischemia. After 2 hours of reperfusion, the ovaries on the right side were removed for examination. The ovarian ischemia/reperfusion injury was evaluated by calculating total antioxidant status, total oxidant status and oxidative stress index; and histopathologic examination of all ovarian rat tissue.

RESULTS

The histologic findings in vardenafil treatment groups were statistically significant decreased edema and follicle degeneration, with vascular congestion, hemorrhage and follicle degeneration being dose-dependent. There were no statistically significant changes in the biochemical parameters.

CONCLUSIONS

According to histopathological examination, low and high dose vardenafil is effective in attenuating ischemia-reperfusion induced ovary injury.

Protective effect of ethyl pyruvate on ischemia-reperfusion injury in rat ovary: biochemical and histopathological evaluation

BACKGROUND

To investigate the protective effect of ethyl pyruvate (EP), an anti-oxidant agent, against ischemia-reperfusion injury in a rat model of ovarian torsion, considering biochemical and histopathological aspects.

METHODS

Forty Wistar Albino rats were divided into five groups: Group I, sham operation; Group II, ischemia alone, Group III, ischemia-reperfusion; Group IV, ischemia-reperfusion+50 mg/kg EP; and Group V, ischemia-reperfusion+100 mg/kg EP. Through laparotomy, 360° torsion was performed and maintained for 3 h, and detorsion was maintained for a further 3 h. Intraperitoneal EP was given 30 min before the surgical procedure. Ovarian tissues and blood samples were obtained after surgery. Malondialdehyde (MDA) and asymmetric dimethyl arginine (ADMA) levels were measured in both plasma and tissue samples. Tissue sections were evaluated histopatologically. Analysis of variance was used for statistical analyses.

RESULTS

In both serum and tissue samples, ADMA and MDA levels were found to be significantly lower in the EP groups compared with the ischemia alone and ischemia-reperfusion groups (p=0.0001). However, no significant difference was found between groups treated with 50 mg/kg or 100 mg/kg EP. On histopathological evaluation, the total tissue injury score was found to be lower in rats treated with EP. No significant difference was detected between groups treated with 50 mg/kg or 100 mg/kg EP.

CONCLUSION

Ethyl pyruvate may exert positive effects in ischemia-reperfusion injury in cases of ovarian torsion. However, no difference was detected between 50 mg/kg and 100 mg/kg EP.

Vitamin E modulates apoptosis and c-jun N-terminal kinase activation in ovarian torsion-detorsion injury

The aim of this study was to evaluate the role of vitamin E in follicular degeneration and to assess histopathological and biochemical changes following ischemia-reperfusion (IR) injury in rat ovaries. Twenty-eight Wistar albino rats were randomly divided into four groups: sham, 4h torsion, 24h detorsion, and a vitamin E group. Thirty minutes before detorsion, a single dose of 200mg/kg vitamin E was administered intraperitoneally. The ovarian histology score was determined, serum levels of malondialdehyde (MDA) and myeloperoxidase (MPO) were measured. The apoptosis of granulosa cells and the phospho-c-jun N-terminal kinase (p-JNK) and phospho-p38 (p-p38) immunoreactivities of these cells were determined. MDA and MPO levels were significantly increased in the torsion and detorsion groups. Hemorrhage, edema, and congestion were also apparent in these groups. In addition, the apoptotic index and the immunoreactivity of p-JNK were highest in the detorsion group, which also showed marked follicular degeneration. However, p-p38 activity was not affected by torsion-detorsion (TD) induction. Vitamin E ameliorated TD-induced histological alterations. It also decreased serum levels of MDA and MPO, reduced the activity of p-JNK in the ovaries, and reduced numbers of apoptotic follicular cells. In conclusion, these data indicate that vitamin E attenuated ovarian follicular degeneration by inhibiting the immunoreactivity of p-JNK and reducing the apoptosis of granulosa cells.

The protective effect of curcumin on ischemia-reperfusion injury in rat ovary

BACKGROUND

To evaluate the protective effects of curcumin in experimental ischemia and ischemia/reperfusion (I/R) injury of rat ovaries.

METHODS

Forty-eight female adult Wistar Albino rats were used. Rats divided into six groups and designed: Sham, Torsion, Detorsion, Sham + Curcumin, Torsion + Curcumin, and Detorsion + Curcumin. Except for the Sham and Sham + Curcumin group, all groups were performed to bilateral adnexal torsion for 3 h. Bilateral adnexal detorsion was implemented in the Detorsion and Detorsion + Curcumin groups. The injection of curcumin was intraperitoneally achieved 30 min before the sham, torsion and detorsion.

RESULTS

Total oxidant status levels (TOS), oxidative stress index (OSI) and histologic scores values of ovarian tissue were higher in the torsion and detorsion groups than the sham group (p < 0.05). There was a strong correlation between the total histologic scores of I/R injury and the OSI (r = 0.809, p < 0.001). By the use of curcumin, a significant decrease was established in the mean levels of oxidant markers and histopathologic scores of the ovarian tissues.

CONCLUSIONS

Administration of curcumin is effective in reversing tissue damage induced by ischemia-reperfusion injury in ovarian torsion.

An experimental model of aortic surgery and the effect of Iloprost on lung injury

OBJECTIVES

Ischemia/reperfusion (I/R) damage of the lung is a frequently encountered complication following aortic surgery. The aim of the present study is to investigate the histopathological effects of Iloprost on pulmonary damage developed after I/R.

DESIGN

Twenty-four Sprague-Dawley rats were randomly divided into 3 groups. In the control group, aortas were not clamped. In the I/R group, aortas were occluded, and after 1 h of ischemia, clamps were removed. After 2 h of reperfusion period, lungs of the rats were extracted. In the I/R + Iloprost group after 1 h of ischemia, Iloprost infusion was initiated, and maintained for the duration of 2 h reperfusion period. For histopathological scoring, density of polymorphonuclear leucocytes, congestion, interstitial edema, and bleeding were semiquantitatively evaluated, and histopathological changes were scored.

RESULTS

In the I/R group, multifocal-marked histopathological changes in 5 (62.5%), and multifocal-moderate histopathological changes in 3 (37.5%) rats were detected. In the I/R + Iloprost group, multifocal-moderate histopathological changes in 4 (50%), and multifocal-mild changes in 4 (50%) rats were detected.

CONCLUSIONS

In the experimental rat model, administration of Iloprost has been shown to have preventive effects for pulmonary damage occurring after I/R generated by infrarenal aortic occlusion.