Pig Kidney Model Research Articles

A A Novel Computed Tomography-Ultrasound Image Fusion Technique for Guiding the Percutaneous Kidney Access.

To describe the feasibility of computed tomography (CT)-ultrasound image fusion technique on guiding percutaneous kidney access in vitro and vivo. we compare CT-ultrasound image fusion technique and ultrasound for percutaneous kidney puncture guidance by using an in vitro pig kidney model. The fusion method, fusion time, ultrasound screening time, and success rate of puncture were compared between the groups. Next, patients with kidney stones in our hospital were randomized in the study of simulated puncture guidance. The general condition of patients, fusion method, fusion time, and ultrasound screening time were compared between the groups. A total of 45 pig models were established, including 23 in CT-ultrasound group and 22 in ultrasound group. The ultrasound screening time in CT-ultrasound group was significantly shorter than that in ultrasound group (P < .001). In addition, the success rate of puncture in CT-ultrasound group was significantly higher than that in ultrasound group (P =.015). Furthermore, in simulated PCNL puncture study, baseline data including age, BMI, and S.T.O.N.E score between the two groups showed no statistical difference. The ultrasound screening time of the two groups was (2.60 ± 0.33) min and (3.37 ± 0.51) min respectively, and the difference was statistically significant (P < .001). Our research revealed that CT-ultrasound image fusion technique was a feasible and safe method to guide PCNL puncture. Compared with traditional ultrasound guidance, CT-ultrasound image fusion technique can shorten the learning curve of PCNL puncture, improve the success rate of puncture, and shorten the ultrasound screening time.

Ex vivo delivery of Mirococept: A dose-finding study in pig kidney after showing a low dose is insufficient to reduce delayed graft function in human kidney.

The complement system plays a pivotal role in the pathogenesis of ischemia-reperfusion injury in solid organ transplantation. Mirococept is a potent membrane-localizing complement inhibitor that can be administered ex vivo to the donor kidney prior to transplantation. To evaluate the efficacy of Mirococept in reducing delayed graft function (DGF) in deceased donor renal transplantation, we undertook the efficacy of mirococept (APT070) for preventing ischaemia-reperfusion injury in the kidney allograft (EMPIRIKAL) trial (ISRCTN49958194). A dose range of 5-25mg would be tested, starting with 10mg in cohort 1. No significant difference between Mirococept at 10mg and control was detected; hence the study was stopped to enable a further dose saturation study in a porcine kidney model. The optimal dose of Mirococept in pig kidney was 80mg. This dose did not induce any additional histological damage compared to controls or after a subsequent 3hours of normothermic machine perfusion. The amount of unbound Mirococept postperfusion was found to be within the systemic dose range considered safe in the Phase I trial. The ex vivo administration of Mirococept is a safe and feasible approach to treat DGF in deceased donor kidney transplantation. The porcine kidney study identified an optimal dose of 80mg (equivalent to 120mg in human kidney) that provides a basis for further clinical development.

Introduction of an ex-vivo pig model for teaching percutaneous nephrolithotomy access techniques.

In North America, obtaining access for percutaneous nephrolithotomy (PCNL) is not often performed by urologists. Hands-on training sessions help to ensure this skill continues within the urological community. An ex-vivo pig kidney model was developed for simulation. This model uses porcine tissues with a fluoroscopic C-arm and standard PCNL equipment. The bullseye or triangulation techniques are both possible. We propose this as a high-fidelity tool for teaching PCNL access. The pig kidney, fat, ribs, flank, and skin were arranged anatomically on a table with fluoroscopy. Hands-on training was provided to residents and urologists using the ex-vivo pig model and a silicone-based percutaneous access model. Questionnaires were given at the end of the session. There was a total 14 responders for each model, with incomplete responses on two surveys. A total of 15% of responders for the pig model and 7% of responders for the silicone model had previous percutaneous access experience. For the pig model, 93% of trainees agreed or strongly agreed that the model was easy to use, and 79% of the silicone model trainees felt the same. After the session, 50% of silicone model trainees and 86% of pig model trainees reported increased confidence in their ability to obtain PCNL access. All the pig model trainees and 71% of the silicone model trainees felt that the simulation activity was worthwhile. The inexpensive but anatomically realistic ex-vivo pig model using real-world equipment provides trainees with an excellent tool to learn PCNL access.

3:46 PM Abstract No. 218 - ■ FEATURED ABSTRACTTargeting and recanalization with rapidly resorbable microspheres versus gelatin sponge particles in a pig kidney model

Purpose Resorbable embolization microspheres (REM) must have a time of resorption quick enough to provide a functional recanalization, and to avoid chronic vascular remodeling. We synthesized calibrated REM that resorbed in less than 24 hours and evaluated the performances of REM of 3 sizes (300-500μm, 500-700μm, and 700-900μm) in terms of targeting and recanalization, by comparison to handcut 1mm gelatin sponge particles (GSP). Materials and Methods Eight pigs underwent polar renal artery embolization with either REM of the 3 sizes or GSP. Angiograms were recorded before embolization, 10 minutes and before pig sacrifice 1 week after embolization. On each angiogram, the number of opacified segments of arteries at each bifurcation level was quantified. We analyzed the partition of the opacified segments and determined the level of occlusion, the percentage of occlusion and the recanalization rate for each product. In pathology, the distribution of GSP was assessed. Results REM 300-500μm occluded distal vessels, in interlobular arterioles in the deep cortex. REM 500-700μm and 700-900μm located more proximally, in the junctional arteries which are anastomotic arteries located at the junction between medulla and cortex. GSP occluded the interlobar arteries, proximally. At D7, recanalization rate of the larger REM was 105%, whereas for the two smaller sizes (500-700μm and 300-500μm) it was respectively 62% and 57%. GSP recanalized at 79%. Conclusion Embolizations with calibrated REM were successful and enabled a precise targeting of the occlusion. REM of different sizes targeted different levels of occlusion in kidney arteries. Within less than one week REM were completely resorbed, left no residual material and inflammation and the arteries recanalized between 60% and 100%. By comparison, handcut GSP provided a variable level of occlusion without actual targeting. They were partly degraded and accompanied by a foreign body reaction and the recanalization rate was important but never complete.

Chronic renoprotective effect of pulsatile perfusion machine RM3 and IGL-1 solution in a preclinical kidney transplantation model

BackgroundMachine perfusion (MP) of kidney graft provides benefits against preservation injury, however decreased graft quality requires optimization of the method. We examined the chronic benefits of MP on kidney grafts and the potential improvements provided by IGL-1 solution.MethodWe used an established autotransplantation pig kidney model to study the effects of MP against the deleterious effects of warm ischemia (WI: 60 minutes) followed by 22 hours of cold ischemia in MP or static cold storage (CS) followed by autotransplantation. MPS and IGL-1 solutions were compared.ResultsAnimal survival was higher in MPS-MP and both IGL groups. Creatinine measurement did not discriminate between the groups, however MPS-MP and both IGL groups showed decreased proteinuria. Chronic fibrosis level was equivalent between the groups. RTqPCR and immunohistofluorescent evaluation showed that MP and IGL-1 provided some protection against epithelial to mesenchymal transition and chronic lesions. IGL-1 was protective with both MP and CS, particularly against chronic inflammation, with only small differences between the groups.ConclusionIGL-1 used in either machine or static preservation offers similar levels of protection than standard MP. The compatibility of IGL-1 with both machine perfusion and static storage could represent an advantage for clinical teams when choosing the correct solution to use for multi-organ collection. The path towards improving machine perfusion, and organ quality, may involve the optimization of the solution and the correct use of colloids.

The Urological Dyna-CT: ex vivo feasibility study of interventional cross-sectional imaging in the endourological operation room

Imaging of the urinary tract and its surrounding tissue still remains challenging, since standard imaging in the urological operation room consists of fluoroscopy and plain X-rays. The combination of a ceiling-mounted X-ray system and a new urological intervention table now allows cross-sectional imaging and 3D reconstruction to be performed in the endourological operation room (Urological Dyna-CT). The imaging quality of the Artis Zee Ceiling (Siemens Medical Solutions, Erlangen, Germany) was assessed using slice images of an ex vivo pig kidney model prepared with artificial stones (plaster of Paris). We compared the image quality of three different examination protocols with this model. 3D reconstruction quality was illustrated by means of retrograde filling of one pig`s urinary tract with a diluted contrast medium. Interventional stone detection and localization is possible with a 5 s low-dose Urological Dyna-CT. Detailed imaging of the collecting system by retrograde pyelography is possible with a high image quality. The combination of an Artis Zee(®) Ceiling (Siemens Medical Solutions, Erlangen, Germany) with our newly developed urological intervention table we call the Urological Dyna-CT. In addition to such standard procedures as fluoroscopy or plain X-rays, cross-sectional imaging and 3D reconstruction of the urinary tract are possible and provide fast and excellent urological imaging.

Renoprotective effect of pulsatile perfusion machine RM3: pathophysiological and kidney injury biomarker characterization in a preclinical model of autotransplanted pig

To assess the effect of machine perfusion (MP) on renal function recovery vs kidney preservation in static cold storage (CS), in a large animal preclinical model. To assess whether MP benefits are dependent on the preservation solution used. Using an established autotransplantation pig kidney model associated with a contralateral nephrectomy we studied the impact of MP against the deleterious effects of warm ischaemia (WI; 60 min), then 22 h of cold ischaemia using MP or static CS, followed by autotransplantation. We used Berzer MP solution (MPS), recommended for MP, and Institut Georges Lopez preservation solution (IGL-1), designed for CS. The pigs were divided into four study groups: MPS-CS: static CS with MPS (n = 7); MPS-MP: renal perfusion with MPS using the Waters Medical Systems (Rochester, MN, USA) RM3 pulsatile machine (n = 7); IGL-CS: static CS with IGL-1 solution (n = 7); IGL-MP: renal perfusion with IGL-1 solution (n = 7). The effect of ischaemia was determined using different variables: pig survival; plasma creatinine; proteinuria; oxidative stress; tubular sodium reabsorption rate; and tissue damage at 1 month. Pig survival was higher in MP and IGL groups compared to MPS-CS. Plasma creatinine levels did not differ among the groups, but proteinuria assay showed significant benefits for the MP vs static CS groups. Histological evaluation of kidney grafts showed more injury in the CS groups than in the MP groups. Urinary measurement of tubular enzyme activity differed substantially among the groups, highlighting the benefits of MP in maintaining brush border integrity. In our model reproducing the conditions of deceased after cardiac arrest donors we show that MP decreases the risk of renal dysfunction and preserves kidney parenchyma. A non-invasive urinary enzyme assay can provide valuable information on graft integrity. The preservation solution used is important as the wrong solution can decrease the benefits of MP.

Trophic Factor and FR167653 Supplementation During Cold Storage Rescue Chronic Renal Injury

The use of organs from deceased after cardiac death and extended criteria donors grew in the last decade. These organs are more sensitive to ischemia-reperfusion injury during transplantation and current preservation protocols do not protect them adequately. In an autotransplanted, deceased after cardiac death donor pig kidney model we evaluated the benefits of supplementation with University of Wisconsin solution trophic factors and FR167653, an inhibitor of p38 mitogen-activated protein kinase. Supplemented solution improved renal recovery and limited ischemia-reperfusion injury, particularly when agents were used in conjunction. Long-term benefits were highlighted by decreased renal fibrosis, as determined by Picrosirius staining, and inflammation, as evaluated by renal cell infiltration. Mechanistic evaluation showed decreased expression of epithelial-to-mesenchymal transition markers, a process involved in renal fibrosis development. Tumor necrosis factor-α was markedly decreased in the treated experimental group. Apoptosis was also decreased, accompanied by decreased p38 mitogen-activated protein kinase phosphorylation. Supplementing the current gold standard kidney preservation protocol with trophic factors and p38 mitogen-activated protein kinase inhibitors markedly increased the quality of grafts in our pig deceased after cardiac death donor model. Hence, this represents a strategy of interest to improve transplantation outcomes.

Water-soluble Polyvinyl Alcohol Microspheres for Temporary Embolization: Development and in Vivo Characteristics in a Pig Kidney Model

To preliminarily examine whether solubility of water-soluble polyvinyl alcohol (PVA) microspheres in blood plasma changes in proportion to their degrees of saponification. The study also examined their feasibility as a temporary embolic agents in the pig renal artery. Three types of PVA microspheres with the degrees of saponification of 97 mol% (S97), 98 mol% (S98), and 99 mol% (S99) were prepared. Seven kidneys in seven miniature pigs were embolized and divided into three groups so there would be at least two kidneys for each type of PVA. One animal in each group was euthanized immediately after angiography at 3 hours after embolization and the other one at 7 days after. In addition, one animal embolized with S99 microspheres was euthanized at 21 days after embolization. With S97 microspheres, the vascular network had recovered to the preembolic state by 3 hours after embolization. With S98 microspheres, blood flow in the third-order branch had been restored in the same period. With S99 microspheres, the second- and lower order branches remained occluded until 21 days. Histopathologic specimens harvested at 3 hours revealed only a trace of PVA for S97 microspheres. With S98 microspheres, the vascular lumen was still found to be filled with PVA gel. With S99 microspheres, swollen microspheres densely filled the vascular lumen even on day 21. Dissolution process in vitro and the duration of arterial occlusion in vivo were possibly related to the degree of saponification of PVA. This result may support feasibility of PVA microspheres as a temporary embolic agent.

Inflammation and Recanalization of Four Different Spherical Embolization Agents in the Porcine Kidney Model

To evaluate the pattern of recanalization and specific inflammatory reaction after superselective embolization with four commercially available spherical embolic agents of different sizes in the mini pig kidney model. In 40 mini pigs, the lower poles of both kidneys were superselectively embolized with Embozene, Embosphere, Bead Block, and Contour SE particles in sizes of 40-120 mircom (Embozene, Embosphere) and 100-300 microm, 500-700 microm, and 700-900 microm (Embozene, Embosphere, Bead Block, Contour SE). After a follow-up time of 4 or 12 weeks, recanalization was determined with angiography. Pathologic and histologic evaluation of the kidneys was performed, and the Banff 97 classification was used to evaluate the extent of vessel wall inflammation. Macroscopically visible ischemic changes were evaluated by using a specific ischemia score. After embolization with Embozene microspheres, larger Embosphere particles, and Bead Block and Contour SE particles, the absence of inflammation or a low inflammation score was observed. Significantly elevated inflammation scores were evident with small Embosphere particles after 4 weeks (mean score, 1.21 +/- 1.0). Distinct recanalization occurred with Contour SE particles (100% recanalization with 100-300-microm particles at 12 weeks, 500-700-microm particles at 4 and 12 weeks, and 700-900-microm particles at 4 weeks). Ischemia scores were highest in the target area in all specimens. Mildly elevated ischemia scores in nontarget tissue areas were indicative of minor nontarget embolization. Except for small Embosphere particles at 4 weeks, the absence of inflammatory reaction to the embolization procedure or only low inflammatory changes were observed with all embolic agents, particle sizes, and follow-up intervals. Recanalization was evident with all embolic agents; however, it was pronounced with Contour SE particles.

Trimetazidine reduces early and long-term effects of experimental renal warm ischemia: A dose effect study

Renal ischemia reperfusion (IR) injury (IRI) is an important mechanism of acute renal failure (ARF) and a crucial factor of tissue damage during vascular surgery. IR may lead to tissue destruction and influence the early and long-term outcome of organs. The anti-anginal medication trimetazidine (TMZ) is a drug, the protective effects of which have been already assessed during cold preservation and warm ischemia (WI). The objective of this dose-effect study was to assess the role of TMZ in severe renal WI model. We have used an established WI pig kidney model associated with a uninephrectomy condition and studied the dose-dependent role of TMZ (1, 5, and 10 mg/Kg, i.v. for 24 hours before WI) against deleterious effects of WI (60 minutes of WI followed by reperfusion) compared with sham-operated (control) and uninephrectomized animals (unif). Direct effect of TMZ was determined using different variables: renal function (creatinine clearance; C(cr)) and indirectly, the consequences on inflammation (cells infiltration), rate of apoptosis, fibrosis development, and renal epithelial cells change into myofibroblast, which defined epithelial to mesenchymal transition (alpha-smooth muscle actin [alpha-SMA] and vimentin expression). TMZ (5 or 10 mg/Kg) significantly increased C(cr) and reduced the inflammatory response prevalent in ischemic kidney injury and rate of apoptosis expression. In addition, the limitation of initial IRI was correlated with an earlier and greater expression of hypoxia-inducible transcription factor-1alpha (HIF-1alpha), which is a hypoxia marker during kidney regeneration. A reduction of the tubulointerstitial development of fibrosis and a limitation of the alpha-smooth muscle actin expression (alpha-SMA) was observed with TMZ treatment. At 3 months, vimentin expression was increased in WI groups without TMZ or low TMZ dose treatment compared with 5 or 10 mg/Kg treated groups. Collectively, these data suggest that TMZ made the warm ischemic kidneys more resistant to the deleterious impact of a single episode of IR and could have a role in preserving the ischemic kidney from long-term damage.

Practical Comparison of Four Nitinol Stone Baskets

The use of stone baskets for repositioning of stones or removal of fragment in conjunction with ureterorenoscopy has become widespread. We tested the performance of the ACMI Sur-Catch NT, Bard Dimension, Boston Scientific Zero-tip, and Cook N-Circle in a pig kidney model of flexible ureterorenoscopy. Opening characteristics of the basket were measured with mechanical calipers at 1-mm increments and compared with published reports to ensure the tested baskets were representative. Pig kidneys were placed in a basin and the ureters secured with a suture to a weight for stability. Flexible renoscopy was performed using a 16F flexible cystonephroscope. An 8-mm calculus was placed in the lower pole. Using each of four designs, the time necessary to grasp the stone, time to release the stone, and total time to move a stone from the lower-pole calix to the upper-pole were recorded. Total time experiments were repeated six times with each basket by three surgeons for a total of 18 attempts, and catch-and-release experiments were repeated six times by four surgeons for a total of 24 attempts per basket. The Sur-Catch was significantly slower for catch and release (P < 0.001) and total time; P < 0.05) compared with all other baskets. There were no differences between the other baskets in either catch, release, or total times. There was no difference between surgeons (P < 0.0634) or between attempts one through six (P = 0.538). Baskets with added complexity of the wire configurations (Sur-Catch) or a deflectable-wire mechanism (Dimension) offer no advantages and may slow capture and release of stones.

Comparison of protective effects of trimetazidine against experimental warm ischemia of different durations: early and long-term effects in a pig kidney model

Acute renal failure (ARF) is often the consequence of an ischemia-reperfusion injury (IRI) and associated with high mortality. Warm ischemia (WI) is a crucial factor of tissue damage, and tissue destruction led by ischemia-reperfusion (I/R) can impact the early and long-term functional outcome. Trimetazidine (TMZ) is an anti-ischemic drug. Previously, we already verified its protective effect on a cold-ischemic pig kidney model by directly adding TMZ into the preservation solution (Faure JP, Baumert H, Han Z, Goujon JM, Favreau F, Dutheil D, Petit I, Barriere M, Tallineau C, Tillement JP, Carretier M, Mauco G, Papadopoulos V, Hauet T. Biochem Pharmacol 66: 2241-2250, 2003; Faure JP, Petit I, Zhang K, Dutheil D, Doucet C, Favreau F, Eugene M, Goujon JM, Tillement JP, Mauco G, Vandewalle A, Hauet T. Am J Transplant 4: 495-504, 2004). In this study, we aimed to study the potential effect of TMZ pretreatment (5 mg/kg iv 24 h before WI) on the injury caused by WI for 45, 60, and 90 min and reperfusion in a WI pig kidney model. Compared with sham-operated (control) and uninephrectomized animals (UNX), TMZ pretreatment significantly reduced deleterious effects after 45 min, and particularly 60 and 90 min, of WI by improving the recovery of renal function and minimizing the inflammatory response commonly prevalent in ischemic kidney injury. Compared with controls (control group and UNX group), it was observed that 1) hypoxia-inducible factor-1 (HIF-1alpha) expression occurred earlier and with a higher intensity in the TMZ-treated groups; 2) the reduction of IRI during the first week following reperfusion was correlated with an earlier and greater expression of stathmin, which is involved in the process of tubular repair; and 3) the tubulointerstitial fibrosis was reduced, particularly after 60 and 90 min of WI. In conclusion, TMZ made the warm-ischemic kidneys more resistant to the deleterious impact of a single episode of I/R and reduced early and long-term subsequent damage.

Modulation of Peripheral-Type Benzodiazepine Receptor During Ischemia Reperfusion Injury in a Pig Kidney Model: A New Partner of Leukemia Inhibitory Factor in Tubular Regeneration

It was demonstrated that postischemic kidney expresses different factors in a pattern that recapitulates expression of these factors in the developing kidney. We investigated whether peripheral-type benzodiazepine receptor (PBR), which belongs to the mitochondrial permeability transition pore and is essential during development, could be influenced by the ischemia-reperfusion injury process when compared with leukemia inhibitor factor (LIF). PBR, LIF, and LIF receptor messengers and proteins were analyzed in adult normal and ischemic kidney under conditions mimicking cardiac arrest: 18 pigs were studied after 60 minutes of warm ischemia and reperfusion for 7 days and compared with sham-operated (Sham, n = 12) and control (CONT, n = 12) groups. The same messengers and proteins were assessed in fetal kidneys. In normal kidney, PBR was expressed in descending and ascending limbs of Henle and in distal tubules. After ischemia-reperfusion injury, PBR mRNA significantly increased between days 1 and 7 in cortex and outer medulla. PBR protein increased between days 1 and 7, and was transiently expressed in proximal tubules at days 1 and 3 and returned to basal level at day 7. LIF messenger and protein increased rapidly at day 1 in proximal tubules. In turn, LIF receptor messenger and protein were not changed during reperfusion. These results suggest that PBR may be implicated in ischemia-reperfusion injury and, particularly, in the regenerative process within proximal tubules with LIF. These new insights open the possibility of novel targets for organ protection and repair.

Influence of colloid, preservation medium and trimetazidine on renal medulla injury.

In organ transplantation, preservation injury is an important factor which could influence short-term and long-term graft outcome. The renal medulla is particularly sensitive to oxidant stress and ischemia-reperfusion injury (IRI). Using an autotransplant pig kidney model, we investigated renal function and medullary damage determined between day 1 and week 2 after 24- or 48-h cold storage in different preservation solutions: University of Wisconsin solution (UW), Hopital Edouard Herriot solution (a high Na+ version of UW), ECPEG (high Na+ preservation solution with PEG) and ICPEG (a high K+ version of ECPEG) with or without trimetazidine (TMZ). TMZ improved renal preservation and increased renal function when added in each preservation solution (particularly HEH and ECPEG). Medullary damage led to the early appearance of trimethylamine-N-oxide (TMAO) followed by 1H-NMR in urine and plasma. TMZ and ECPEG is the most efficient association to reduce medullary damage. This study clarifies the role of colloid and polarity solution and the role of mitochondrial protection by TMZ.

Evidence for protective roles of polyethylene glycol plus high sodium solution and trimetazidine against consequences of renal medulla ischaemia during cold preservation and reperfusion in a pig kidney model.

The renal medulla is particularly sensitive to oxidant stress and to ischaemia-reperfusion injury (IRI). In organ transplantation, delayed graft function is an important problem and cold ischaemia is thought to be the most important factor in short- and long-term complications. Our aim was to study cold-induced damage in proximal tubular segments and renal medulla osmolite excretion during use of various preservation solutions, and to clarify the role of trimetazidine (TMZ) in limiting renal dysfunction. Using an autotransplanted pig kidney model, we assessed renal tubule function, medullary osmolite excretion and renal damage between day 1 and week 2 after 24 or 48 h cold storage in University of Wisconsin solution (UW), Celsior and ECPEG (two new high Na(+) preservation solutions) or the Hopital Edouard Herriot solution (HEH; a high Na(+) version of UW). In additional groups, TMZ was added to these preservation solutions for 24 and 48 h cold storage. Renal function was reduced under these preservation conditions. Tubular injury was associated with aminoaciduria and with a limited Na(+) reabsorbtion. Medullary damage led to the early appearance of trimethylamine-N-oxide and dimethylamine in urine. However, renal damage was modulated by preservation conditions. In addition, TMZ added to each of the solutions efficiently protected against IRI even after prolonged preservation. TMZ efficiently protected kidneys against damage when added to the HEH and particularly ECPEG solutions, even after 24 h cold storage. These findings point to a role for drugs that target mitochondria, and demonstrate that TMZ may provide a valuable therapeutic tool against IRI and could be included in therapeutic protocols.

Evidence for a Mitochondrial Impact of Trimetazidine during Cold Ischemia and Reperfusion

In organ transplantation, ischemia-reperfusion injury (IRI) has been implicated in delayed graft function (DGF) as well as in short- and long-term complications. Using an autotransplant pig kidney model, changes in renal function and morphology were determined after different periods of cold ischemia in kidneys preserved in the University of Wisconsin solution (UW), high-Na⁺ version of UW (HEH) or Celsior (CEL) a newly developed high-Na⁺ solution, with or without trimetazidine (TMZ). Kidney function was better preserved in CEL, UW and particularly HEH in combination with TMZ, particularly after 48 and 72 h. Mitochondria integrity was improved in TMZ-preserved groups. This study indicates that TMZ is efficiently protective against IRI even after prolonged preservation and in different preservation solutions.

Evidence for a protective role of trimetazidine during cold ischemia: targeting inflammation and nephron mass

Ischemia–reperfusion injury (IRI) is associated with an increased risk of acute rejection, delayed graft function, or chronic graft dysfunction. Mitochondria plays a central role in this process. Using an autotransplant pig kidney model, changes in renal function and morphology were determined after different periods of cold ischemia in kidneys preserved in the University of Wisconsin solution (UW), high-Na + version of UW (HEH) or Celsior (CEL) a newly developed high-Na + solution, with or without trimetazidine (TMZ). Kidney function was better preserved in HEH after 24 hr and particularly 48- and 72-hr cold storage than in CEL and UW. TMZ improved the preservation quality when added to the different solutions tested, particularly after 48- and 72-hr cold storage. Interstitial fibrosis and tubular atrophy were reduced in HEH with TMZ. CD4 + T-cell infiltration was also modulated by the preservation conditions. Peripheral-type benzodiazepine receptor (PBR) positive cells infiltration was also modulated by preservation conditions. TMZ was efficient to reduce IRI when added in the various preservation solutions. These results suggest that protection of the mitochondrial function should be a major target to limit IRI. In addition, this study outlines the role of CD4 + T cells and PBR expression in inflammatory responses after IRI.

A modified University of Wisconsin preservation solution with high-NA+ low-K+ content reduces reperfusion injury of the pig kidney graft.

Ischemia-reperfusion injury has been associated with both early and late effects on allografts in the form of delayed graft function and decreased graft survival. Recent studies demonstrated that functional parameters were influenced by cold storage conditions and particularly the ratio of Na+:K+ of the preservation solution. We have extended this study to examine whether the high-Na+ low-K+ formulation of Belzer's solution (HEH) was efficient in an autotransplanted pig kidney model when compared with the classical low-Na+ high-K+ University of Wisconsin solution and the new high-Na+ low-K+ Celsior solution. Kidneys were harvested, cold flushed, and preserved for 24, 48, or 72 hr with HEH, Celsior solution, or University of Wisconsin solution and autotransplanted. Renal function was determined on days 1, 3, 7, and 14, and at 4 to 16 weeks after autotransplantation. Histologic changes and cell infiltration were assessed on kidney biopsy specimens taken after reperfusion (30-40 min), at days 5 and 14, and at 4 to 5 and 10 to 12 weeks after surgery. Peripheral benzodiazepine receptor (PBR), a structural mitochondrial protein, was also studied. Cold storage in HEH resulted in reduction of delayed graft function and renal damage, with a decrease in interstitial inflammation. HEH reduced interstitial fibrosis, tubular atrophy, and improved PBR expression. This study suggests that cold preservation in HEH has a beneficial action in in vivo renal preservation and reduces tubular necrosis, interstitial inflammation, and fibrosis in these groups. In addition, PBR detection was correlated to the level of preservation integrity.

Modulation of peripheral-type benzodiazepine receptor levels in a reperfusion injury pig kidney-graft model.

Ischemia-reperfusion injury is associated with an increased risk of acute rejection, delayed graft function, or chronic graft dysfunction. Mitochondria play a central role in this process. Using an autotransplantation pig kidney model, both early (40 min and 7 days) and late (2-16 weeks) changes in renal function and morphology were determined after different periods of cold ischemia in University of Wisconsin or Euro-Collins solutions. We have also investigated the expression of the peripheral-type benzodiazepine receptor (PBR), which is also critical in maintaining outer mitochondrial membrane stability. Function of the kidneys was better preserved after 1 hr and 24 hr than after 48 hr and 72 hr in Euro-Collins and University of Wisconsin solutions. Medulla injury was reduced in 1 hr-preserved and 24 hr-preserved groups. PBR was found to be present in epithelial cells of the deep cortical and outer medulla in both normal human and well-preserved pig kidneys. PBR expression was modulated by ischemia-reperfusion injury and the concurrent tubular injury and repair processes. This study indicates that PBR expression correlates with the quality of kidney preservation and might serve as an index of kidney and mitochondria viability. Moreover, these data suggest that PBR might be involved in membrane biogenesis during reperfusion. In addition, considering the identical localization of PBR in human and pig kidneys, these findings could have a direct application in human clinical settings of kidney pathology.