Iloprost for the attenuation of ischaemia/reperfusion injury in a distant organ

EARLY AND CONCOMITANT ADMINISTRATION OF NOREPINEPHRINE AND ILOMEDIN IMPROVES MICROCIRCULATORY PERFUSION WITHOUT IMPAIRING MACROCIRCULATION IN AN INTESTINAL ISCHEMIA-REPERFUSION INJURY SWINE MODEL: A RANDOMIZED EXPERIMENTAL TRIAL

ABSTRACT

Background: Intestinal ischemia-reperfusion injury is associated with both macrocirculatory and microcirculatory failure. Association of a vasoconstrictor in combination with a vasodilator such as ilomedin may improve macrocirculation parameters, microcirculation perfusion and reduce endothelial dysfunction. The primary objective was to demonstrate a difference in mean arterial pressure (MAP) after intestinal reperfusion with the concomitant administration of norepinephrine and ilomedin during ischemia compared with traditional hemodynamic treatment strategies (fluid resuscitation and vasopressors only). Secondary objectives were to demonstrate an improvement in peripheral and intestinal microcirculatory perfusion and endothelial dysfunction after intestinal reperfusion using this association. Methods: We conducted a randomized preclinical trial in 21 large white pigs, in which a 2-h small bowel ischemia was performed using a segmental mesenteric occlusion model, followed by a 2-h reperfusion. Pigs were randomized into the following three groups: goal-directed fluid therapy, early administration of norepinephrine before reperfusion and early administration of ilomedin and norepinephrine before reperfusion. Macrocirculatory (MAP and Cardiac Index (CI), microcirculatory (Sublingual with SideStream Dark Field system and intestinal hemoglobin oxygen saturation with hyperspectral imaging) measurements and biological analysis (biomarkers of endothelial dysfunction) were performed. Results: There were no significant differences in the MAP ( P = 0.499) and the CI ( P = 0.659) between the three groups. Perfused vessel density in sublingual microcirculation was significantly higher immediately after reperfusion and 2 h after reperfusion in the early administration of ilomedin and norepinephrine group compared with the other two groups ( P < 0.05). Hemoglobin oxygen saturation measured at the intestinal level was significantly higher immediately after reperfusion in the early administration of ilomedin and norepinephrine group compared with the other two groups ( P < 0.01). There were no significant differences in biomarkers of endothelial dysfunction between the three groups. Creatinine, AST and alkaline phosphatases increased significantly 2 h after reperfusion in the early administration of ilomedin and norepinephrine group compared with baseline ( P < 0.05). Conclusions: Early administration of norepinephrine and ilomedin during ischemia improved short-term postreperfusion sublingual and intestinal microcirculation without worsening macrocirculatory parameters in an intestinal ischemia-reperfusion injury model. However, use of this strategy seemed to worsen both liver and kidney function.

Prevention of Delayed Graft Function in Kidney Transplant Recipients through a Continuous Infusion of the Prostaglandin Analogue Iloprost: A Single-Center Prospective Study

BACKGROUND

Delayed graft function (DGF) is common after kidney transplantation from deceased donors and may significantly affect post-transplant outcomes. This study aimed to evaluate whether an innovative approach, based on the administration of the intravenous prostaglandin analogue iloprost, could be beneficial in reducing the incidence of DGF occurring after kidney transplantation from deceased donors.

METHODS

This prospective, randomized (1:1), placebo-controlled study enrolled all consecutive patients who received a kidney transplant from a deceased donor from January 2000 to December 2012 and who were treated in the peri-transplant period with the prostaglandin analogue iloprost at 0.27 μg/min through an elastomeric pump (treatment group) or with a placebo (control group).

RESULTS

A total of 476 patients were included: DGF was reported in 172 (36.1%) patients in the entire cohort. The multivariate analysis showed that the donor's age > 70 years (OR 2.50, 95% confidence interval (CI): 1.40-3.05, p < 0.001), cold ischemia time > 24 h (OR 2.60, 95% CI: 1.50-4.51, p < 0.001), the donor's acute kidney injury (OR 2.71, 95% CI: 1.61-4.52, p = 0.021) and, above all, the recipient's arterial hypotension (OR 5.06, 95% CI: 2.52-10.1, p < 0.0001) were the strongest risk factors for developing post-transplant DGF. The incidence of DGF was 21.4% in the treatment group and 50.9% in the control group (p < 0.001). Interestingly, among patients who developed DGF, those who received iloprost had a shorter duration of post-transplant DGF (10.5 ± 8.3 vs. 13.4 ± 6.7, days, p = 0.016).

CONCLUSIONS

This study showed that the use of a continuous infusion of iloprost could safely and effectively reduce the incidence of DGF in recipients of deceased-donor kidneys, allowing a better graft functionality as well as a better graft survival.

The effect of iloprost and N-acetylcysteine on skeletal muscle injury in an acute aortic ischemia-reperfusion model: an experimental study

Objective. The objective of this study was to examine the effects of iloprost and N-acetylcysteine (NAC) on ischemia-reperfusion (IR) injuries to the gastrocnemius muscle, following the occlusion-reperfusion period in the abdominal aorta of rats. Materials and Methods. Forty male Sprague-Dawley rats were randomly divided into four equal groups. Group 1: control group. Group 2 (IR): aorta was occluded. The clamp was removed after 1 hour of ischemia. Blood samples and muscle tissue specimens were collected following a 2-hour reperfusion period. Group 3 (IR + iloprost): during a 1-hour ischemia period, iloprost infusion was initiated from the jugular catheter. During a 2-hour reperfusion period, the iloprost infusion continued. Group 4 (IR + NAC): similar to the iloprost group. Findings. The mean total oxidant status, CK, and LDH levels were highest in Group 2 and lowest in Group 1. The levels of these parameters in Group 3 and Group 4 were lower compared to Group 2 and higher compared to Group 1 (P < 0.05). The histopathological examination showed that Group 3 and Group 4, compared to Group 2, had preserved appearance with respect to hemorrhage, necrosis, loss of nuclei, infiltration, and similar parameters. Conclusion. Iloprost and NAC are effective against ischemia-reperfusion injury and decrease ischemia-related tissue injury.

Contribution of RhoA/Rho-kinase/MEK1/ERK1/2/iNOS pathway to ischemia/reperfusion-induced oxidative/nitrosative stress and inflammation leading to distant and target organ injury in rats

The small G protein RhoA and its downstream effector Rho-kinase play an important role in various physiopathological processes including ischemia/reperfusion (I/R) injury. Reactive oxygen and nitrogen species produced by iNOS and NADPH oxidase are important mediators of inflammation and organ injury following an initial localized I/R event. The aim of this study was to determine whether RhoA/Rho-kinase signaling pathway increases the expression and activity of MEK1, ERK1/2, iNOS, gp91(phox), and p47(phox), and peroxynitrite formation which result in oxidative/nitrosative stress and inflammation leading to hindlimb I/R-induced injury in kidney as a distant organ and gastrocnemius muscle as a target organ. I/R-induced distant and target organ injury was performed by using the rat hindlimb tourniquet model. I/R caused an increase in the expression and/or activity of RhoA, MEK1, ERK1/2, iNOS, gp91(phox), p47(phox), and 3-nitrotyrosine and nitrotyrosine levels in the tissues. Although Rho-kinase activity was increased by I/R in the kidney, its activity was decreased in the muscle. Serum and tissue MDA levels and MPO activity were increased following I/R. I/R also caused an increase in SOD and catalase activities associated with decreased GSH levels in the tissues. Y-27632, a selective Rho-kinase inhibitor, (100µg/kg, i.p.; 1h before reperfusion) prevented the I/R-induced changes except Rho-kinase activity in the muscle. These results suggest that activation of RhoA/Rho-kinase/MEK1/ERK1/2/iNOS pathway associated with oxidative/nitrosative stress and inflammation contributes to hindlimb I/R-induced distant organ injury in rats. It also seems that hindlimb I/R induces target organ injury via upregulation of RhoA/MEK1/ERK1/2/iNOS pathway associated with decreased Rho-kinase activity.

Affirmative effects of iloprost on apoptosis during ischemia-reperfusion injury in kidney as a distant organ

OBJECTIVE

Apoptosis and its regulatory mechanisms take part in renal ischemia-reperfusion (I/R) injury which can result in acute renal failure and the inhibition of the caspase is considered as a new therapeutic strategy. In this context, we investigated the antiapoptotic and cytoprotective effects of iloprost, a prostacyclin analog, in kidney as a distant organ.

METHODS

Wistar albino rats were randomized into five groups (n = 12 in each) as sham, ischemia, I/R, iloprost (10 μg kg(-1)), and I/R + iloprost (10 μg kg(-1)). A 4 h reperfusion procedure was carried out after 4 h of ischemia. Caspase-8 was evaluated for death receptor-induced pathways, whereas caspase-9 was evaluated for mitochondria-dependent pathways and caspase-3 was investigated for overall apoptosis. Superoxide dismutase (SOD) enzyme activity and nitrite content as an indicator of nitric oxide (NO) production were also analyzed in kidney tissues.

RESULTS

Caspases-3, -8, and -9 were all significantly elevated in both ischemia and I/R groups compared to the sham group; however, treatment with iloprost reduced caspases-3, -8, and -9. SOD enzyme activity was attenuated by iloprost when compared to ischemic rats. The different effects of NO were found which change according to the present situation in ischemia, I/R, and treatment with iloprost.

CONCLUSIONS

These findings suggested that iloprost prevents apoptosis in both receptor-induced and mitochondria-dependent pathways in renal I/R injury and it may be considered as a cytoprotective agent for apoptosis. Understanding the efficiency of iloprost on the pathways for cell death may lead to an opportunity in the therapeutic approach for renal I/R injury.

The use of a prostacyclin analog, iloprost, as an adjunct to uterus preservation with histidine-tryptophan-ketoglutarate solution

INTRODUCTION

Although assisted reproductive techniques have made most causes of both male and female infertility treatable, uterine factor infertility is not able to therapy. Therefore, transplantation of the uterus has been suggested as a future possible cure. Organ preservation solutions seek to reduce reperfusion injury. Since iloprost is an antioxidant with cytoprotective properties, we investigated its potential positive effects in histidine-tryptophan-ketoglutarate (HTK) solution after 4 or 24 h cold storage period of the rat uterus.

METHODS

We divided 24 female Wistar-albino rats into four groups: Group 1 had the uterus tissue stored in HTK solution at 4 °C for 4h. Group 2, the tissue was stored in HTK solution combined with iloprost (10(-8) M) for 4h at 4 °C. The same procedures were repeated for 24 h for Groups 3 and 4 respectively. Tissue levels of malondialdehyde (MDA) and nitric oxide (NO), as indicators of oxidative stress were determined with histopathological evaluations.

RESULTS

MDA and NO levels were compared between the group 1 vs 3; and 2 vs 4. No significant difference was observed between the groups. Cold storage for 24 h produced alterations in histological appearances that were mitigated by the addition of iloprost to HTK solution.

CONCLUSION

In conclusion, addition of iloprost to HTK solution reversed the histological alterations after 24h-cold storage of the rat uterus.

The effect of iloprost on renal dysfunction after renal I/R using cystatin C and beta2-microglobulin monitoring

The purpose of this study was to investigate the effect of iloprost, a cytoprotective prostacyclin analog, on renal injury during unilateral renal I/R in rats and to determine whether the levels of serum cystatin C (CyC) and beta2-microglobulin (B2M), as markers of glomerular function, might denote this injury. Thirty-two Wistar rats were randomized into four groups (n = 8) as follows: control (sham laparotomy), renal I/R (60-min left renal ischemia and 120-min reperfusion), renal I/R + iloprost (20 ng kg(-1) min(-1) infusion during renal I/R period, i.v.), and control + iloprost. Blood and kidney tissue samples were obtained for biochemical and histological analysis from all rats. Serum urea, creatinine, CyC, and B2M levels were evaluated for biochemical analysis. Histopathological changes in renal structure were examined for histological analysis. Serum urea, creatinine, and CyC levels were significantly increased in the renal I/R group. Iloprost treatment decreased these three markers in the renal I/R + iloprost group. beta2-Microglobulin levels were not significantly changed in any group. Histological analyses showed that renal I/R elicited significant renal injury, whereas iloprost significantly decreased I/R-induced renal injury. Serum CyC level is one of the good indicators of acute renal damage due to I/R produced by renal artery occlusion. In contrast, we have shown that there are no significant changes in the levels of serum B2M levels that would make it an accurate diagnostic tool for detecting acute changes in renal injury subject to renal I/R in rats.