Evaluation of a Novel Cold Storage Solution (HBS) in a Rat Kidney Transplant Model

Dynamic regulation of anti-oxidation following donation repairing after circulatory determined death renal transplantation with prolonged non-heart-beating time

Donation after circulatory-determined death (DCD) is an important part of renal transplantation. Therefore, DCD renal transplantation animal model should be established to study the mechanism of organ injury. Here, we established a stable DCD rat renal transplantation model and investigated the dynamic regulation of graft self-repairing and antioxidant capacities with different non-heart-beating times (NHBTs). Male Sprague-Dawley rats were randomly divided into four groups with the NHBT of the donors from 0 to 15, 30, and 45 minutes. Recipients in long NHBT groups had a significantly lower survival rate and poorer graft function than those in short NHBT groups. Grafts from the 15-minute and 30-minute NHBT groups showed light and severe injury respectively at an early stage after transplantation and recovered within 7 days after transplantation, whereas the self-repairing of the grafts in the 45-minute NHBT group was delayed. The expressions of proliferating cell nuclear antigen (PCNA) and von Willebrand factor (vWF) were dependent on NHBT. The expression of antioxidant proteins paralleled graft recovery. In conclusion, the recipients can up-regulate antioxidant capacity to enhance graft self-repairing in DCD renal transplantation. Prolonged NHBT can delay the self-repairing and antioxidation of grafts.

Preservation Solutions for Kidney Transplantation: History, Advances and Mechanisms

Solid organ transplantation was one of the greatest medical advances during the past few decades. Organ preservation solutions have been applied to diminish ischemic/hypoxic injury during cold storage and improve graft survival. In this article, we provide a general review of the history and advances of preservation solutions for kidney transplantation. Key components of commonly used solutions are listed, and effective supplementations for current available preservation solutions are discussed. At cellular and molecular levels, further insights were provided into the pathophysiological mechanisms of effective ingredients against ischemic/hypoxic renal injury during cold storage. We pay special attention to the cellular and molecular events during transplantation, including ATP depletion, acidosis, mitochondrial dysfunction, oxidative stress, inflammation, and other intracellular mechanisms.

An ex vivo comparison of adenosine and lidocaine solution and University of Wisconsin solution for hypothermic machine perfusion of porcine kidneys: potential for development

BACKGROUND

The optimal hypothermic machine perfusion (HMP) solution has not yet been developed. An adenosine and lidocaine (AL) solution has been shown to be protective in cardiac preservation. The aim of the present study was to examine a modified AL solution with low Ca²⁺, 16 mM Mg²⁺, and 4% albumin on kidney preservation compared with University Wisconsin solution (UW).

METHODS

Twenty donation of organs after cardiac death porcine kidneys underwent HMP for 10 h (AL, n = 10; UW, n = 10) and then 2 h of normothermic reperfusion. Perfusion dynamics, functional parameters, histology, and real-time microdialysis were used to assess kidney responses and viability.

RESULTS

During HMP, modified AL-perfused kidneys maintained higher flow rates (21.5 versus 17.9 mL/min/100 g, P = 0.01), with perfusion flow index during the first 3 h 25% greater than with UW (AL = 0.50 ± 0.2, UW = 0.40 ± 0.17 mL/min/100 g/mmHg; P = 0.03), followed by an increase in UW kidneys which was not significantly different to AL over the remaining 7 h (0.54 versus 0.55 mL/min/100 g/mmHg, respectively). During warm reperfusion, there were no significant differences between the two HMP groups in creatinine clearance, oxygen, and glucose consumption between groups. Modified AL kidneys had significantly lower perfusate lactates (3.1 versus 4.1 mmol/L, P = 0.04) during reperfusion and lower cortical lactate levels (AL = 0.66 ± 0.31, UW = 0.89 ± 0.53 mM, P = 0.33). Histology showed similar degrees of reperfusion injury.

CONCLUSIONS

We conclude that HMP with modified AL solution showed improved perfusion compared with UW and lower perfusate lactate levels during warm reperfusion. Further modification of the AL composition is warranted and may lead to more rapid kidney stabilization and improved graft viability assessment, potentially expanding donor pools.

Protective effect of zinc-N-acetylcysteine on the rat kidney during cold storage

Cold storage of kidneys before transplantation is problematic because of the limited survival time of the allografts. In this study, zinc-N-acetylcysteine (ZnNAC) was shown to be a potent endonuclease inhibitor and antioxidant, and it was tested as a potential additive to a cold storage solution for kidney preservation. Exposure of normal rat kidney NRK-52E cells to ZnNAC resulted in zinc delivery to the cells as determined by TFL-Zn fluorophore and partial protection of the cells against injury by cold storage in University of Wisconsin solution (UWS) as measured by propidium iodide assay. Ex vivo, rat kidneys demonstrated time- and temperature-dependent DNA fragmentation as assessed by TUNEL assay, indicating irreversible cell death. DNA fragmentation was faster in the medulla than in the cortex, and tubules were affected more than glomeruli. Perfusion of rat kidneys with cold ZnNAC solution in UWS significantly inhibited cell death both in the cortex and medulla at concentrations of 0.3-30 mM compared with UWS alone, with a maximum effect at 1-10 mM ZnNAC. Cold storage of the kidney significantly increased quantities of cleaved caspase-3 and endonuclease G (EndoG) in the tissue, which were abolished by 10 mM ZnNAC, indicating its ability to suppress both caspase-dependent and -independent cell death. Therefore, supplementation of UWS with ZnNAC can decrease DNA fragmentation and protect kidney allografts from cell death due to cold storage.