Role of combination of L-arginine and α-tocopherol in renal transplantation ischaemia/reperfusion injury: a randomized controlled experimental study in a rat model

A Rat Model of Orthotopic Kidney Transplantation Based on Nonanastomotic Technique

BACKGROUND

Renal transplantation is an effective treatment for end-stage renal disease, which involves pathophysiologic processes such as ischemia-reperfusion injury and immune rejection. The degree of ischemia-reperfusion injury is closely related to the functional state of the transplanted kidney. At present, the allogeneic kidney transplantation model has been widely used in related research. The traditional kidney transplantation model has the disadvantages of complicated vascular anastomosis, difficulty in ureteral reconstruction. The aim of this study was to establish a rat autologous orthotopic kidney transplantation model based on non-anastomotic technique.

METHODS

Inbred Wistar rats weighing 260 to 280 g were selected. The rats were anesthetized by intraperitoneal injections of 40 mg/kg body weight pentobarbital sodium. We exposed and freed the left kidney after laparotomy and separated the left renal artery and left renal vein, abdominal aorta, and posterior vena cava. A purse-string suture with a diameter of 1 to 2 mm was made through the tunica media of the abdominal aorta. A puncture was made through the center of the purse-string suture. The in-dwelling needle was placed in the renal artery along the blood flow direction, and was infused with constant flow of 4°C heparinized lactated ringer's solution until the kidney became pale yellow. The renal vein was ligated and the renal artery was clamped. The in-dwelling needle was removed, purse-string suture was ligated, and the kidney was stored in a self-made autologous kidney transplant cold storage bag for 4 hours. We then opened the vein and artery, removed the cold storage bag, and rewarmed with 37°C normal saline. The abdomen was then closed layer by layer.

RESULTS

Fifty-two orthotopic renal transplantations were performed, which included pre-experimental (40 operations) and experimental stages (12 operations). The success rates of the 2 stages were 75% and 91.7%, respectively. The main causes of failure were intraoperative hemorrhagic shock and postoperative infection. The operation time of orthotopic renal transplantation was 360 ± 30 minutes, including 30 ± 10 minutes for dissociation and management of kidney and blood vessels, 1 ± 0.5 minutes for warm ischemia and 240 ± 10 minutes for cold storage. Rats were sacrificed at 1 day and 7 day respectively. The rats were in good condition after operation. They could eat and drink freely. At 24 hours and 1 week after transplantation, the kidney's blood supply was good, the intestine was light or showed no adhesions, and the abdominal cavity had no ascites or peculiar smell. Hematoxylin & eosin (H&E) staining showed that there were no obvious pathologic changes in the sham group. The orthotopic kidney transplantation 1-day group showed pathologic changes of ischemia-reperfusion, such as swelling, necrosis, shedding, and cast formation of renal tubular cells. The orthotopic kidney transplantation 7-day group recovered well, with mild dilation of the renal capsule and mild dilatation of the renal tubules.

CONCLUSION

The new model of autologous kidney transplantation is simple to use, does not require vascular anastomosis and ureteral reconstruction, and has a high success rate.

Carbon monoxide-releasing molecule-3: Amelioration of renal ischemia reperfusion injury in a rat model

Purpose

Despite the role of carbon monoxide in ameliorating ischemia-reperfusion injury (IRI), its use in the clinical setting is restricted owing to its toxicity. Herein, we investigated the in vivo effects of carbon monoxide–releasing molecule-3 (CORM-3) on IRI.

Materials and Methods

Fifteen rats were equally and randomly divided into three groups: sham (right nephrectomy), control (right nephrectomy and left renal ischemia), and CORM-3 (right nephrectomy and CORM-3 injection before left renal ischemia). Kidney tissues and blood samples collected from sacrificed rats were evaluated to determine the renoprotective effect and mechanism of CORM-3.

Results

Concentrations of serum creatinine and kidney injury molecule-1 in the CORM-3 group were significantly lower than in the control group after 75 minutes of IRI (1.2 vs. 2.4 mg/dL, p=0.01, and 292 vs. 550 pg/mL, p<0.001, respectively). Furthermore, the CORM-3 group exhibited a higher portion of normal tubules and glomeruli. TUNEL staining revealed fewer apoptotic renal tubular cells in the CORM-3 group than in the control group. The expression of 960 genes in the CORM-3 group was also altered. Pretreatment with CORM-3 before renal IRI produced a significant renoprotective effect. Fifteen of the altered genes were found to be involved in the peroxisome proliferator-activated receptors signaling pathway, and the difference in the expression of these genes between the CORM-3 and control groups was statistically significant (p<0.001).

Conclusions

CORM-3 ameliorates IRI by decreasing apoptosis and may be a novel strategy for protection against renal warm IRI.

Influence of ezetimibe on selected parameters of oxidative stress in rat liver subjected to ischemia/reperfusion

INTRODUCTION

Ischemia/reperfusion (I/R) is considered to be one of the main causes of liver damage after transplantation. The authors evaluated the effect of ezetimibe on selected oxidative stress parameters in ischemic/reperfused (I/R) rat liver.

MATERIAL AND METHODS

Rats were administered ezetimibe (5 mg/kg) (groups E and E-I/R) or saline solution (groups C and C-I/R) intragastrically for 21 days. Livers of animals in groups C-I/R and E-I/R were subjected to 60 min of partial ischemia (left lateral and median lobes) followed by 4 h of reperfusion. Alanine and asparagine aminotransferase (ALT, AST) activity was determined in blood before I/R and during reperfusion (at 15 and 240 min). After the reperfusion period, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) and glutathione peroxidase (GPx) were determined in liver homogenates using colorimetric methods.

RESULTS

Ezetimibe caused a significant increase in GSH level in groups subjected to I/R (E-I/R (99.91 ±9.01) vs. C-I/R (90.51 ±8.87), p < 0.05). Additionally, under I/R the decrease of GPx activity in the drug-treated group was lower compared to the non-treated group (E-I/R (3.88 ±1.11) vs. E (5.31 ±1.83), p = 0.076). Neither ezetimibe nor I/R affected SOD or MDA levels. I/R produced a significant increase in aminotransferase levels (ALT240-0: C-I/R (42.23 ±43.56) vs. C (9.75 ±11.09), and E-I/R (39.85 ±26.53) vs. E (4.38 ±1.36), p < 0.05 in both cases; AST 240-0: E-I/R (53.87 ±17.23) vs. E (24.10 ±9.66), p < 0.05) but no effect of ezetimibe on those enzymes was found.

CONCLUSIONS

Ezetimibe demonstrates antioxidant properties in rat livers subjected to I/R. However, neither a hepatoprotective nor a hepatotoxic effect of ezetimibe was demonstrated, regardless of I/R.

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.