An examination of the effects of solutions containing histidine and lactobionate for heart, pancreas, and liver preservation in the rat.

Fifty-five rat pancreas transplants, 18 rat heart transplants, and 41 rat liver transplants were performed using standard UW solution, the new HL solution (HL-I), or a modified HL solution (HL-II). Storage times of 18 hr were used in the heart preservation experiments, 24 hr in the liver preservation experiments, and 48 or 72 hr in the pancreas preservation experiments. HL-I solution was superior to both HL-II and UW solution for heart preservation (1-week graft survival rates of 100% [7/7], 0% [0/5], and 50% [3/6], respectively). HL-I and HL-II were superior to UW for 24 hr liver preservation (1-week graft survival rates of 78% [11/14], 80% [8/10], and 29% [5/17], respectively). In contrast, HL-II was superior to both HL-I and UW solutions for pancreas preservation following both 48-hr preservation and 72-hr preservation. Satisfactory graft function was achieved in 100% (7/7), 40% (6/15), and 44.4% (4/9) of pancreases transplanted after 48 hr using HL-II, HL-I, and UW solutions, respectively, and in 50% (4/8), 0% (0/8), and 0% (0/8) following 72-hr preservation. Histidine- and lactobionate-containing solutions thus represent a further improvement in organ preservation by simple cold storage.     

Evaluation of UW solution in rat kidney preservation. II. The effect of pharmacological additives

The present studies show clearly that both dexamethasone and insulin can be omitted without altering the efficacy of UW. Adenosine and glutathione are both helpful additives, as is allopurinol. These findings suggest an important role of reperfusion injury after preservation, and confirm the benefits of adding pharmacological agents likely to reduce this injury. Cold ischemic damage was significantly ameliorated by UW solution in this stringent model of rat kidney preservation for 48 hr. A substantially simplified modification of UW solution has been shown to give equally effective kidney preservation, after removal of hydroxyethyl starch, dexamethasone, and insulin. Adenosine, glutathione, and allopurinol have been confirmed as helpful pharmacological additives. These findings have defined some of the mechanisms of effectiveness of UW solution and suggest avenues of further exploration to improve simple hypothermic storage and to prevent reperfusion injury.     

A comparison of some simplified lactobionate preservation solutions with standard UW solution and Eurocollins solution for pancreas preservation.

Fifty-two rat pancreas transplants were performed to investigate which components of the UW solution were essential for successful pancreas preservation. LEW rats were used and the pancreata stored at 4 degrees C for 48 hr after flushing with commercial UW solution (ViaSpan, DuPont Pharmaceuticals) or a number of simplified solutions. Following storage the pancreata were transplanted into syngeneic recipient animals with streptozotocin-induced diabetes mellitus. Graft function was assessed by regular postoperative blood sugar measurements and a glucose tolerance test on the 14th postoperative day. With commercial UW solution, 4 of 9 recipients (44%) showed satisfactory graft function, while only one of 5 pancreata preserved using Eurocollins solution demonstrated satisfactory function. With solution A, in which hydroxyethyl starch and insulin were omitted from the standard UW solution, 3 of 7 recipients (43%) showed satisfactory function. Omission of glutathione, allopurinol, and adenosine from this solution (solution B) gave satisfactory function in 4 of 8 cases (50%). Substitution of raffinose in solution B with an equimolar concentration of glucose (solution C) resulted in acceptable function in 5 of 8 cases (62%). Increasing the raffinose concentration in solution B to 100 mM/L resulted in only 2 of 8 grafts (25%) with adequate function. By contrast, reversing the Na/K concentrations in solution A resulted in 100% (7/7) satisfactory graft function. We conclude that the rat pancreas can be successfully transplanted following 48-hr cold preservation using UW solution and some simplified versions, and that a substantially simplified lactobionate-based solution with a reversed sodium/potassium ratio improved survival.     

Important components of the UW solution.

The UW solution for preservation of the liver, kidney, and pancreas contains a number of components, and the importance of each of these has not been fully resolved. In the studies reported here the importance of glutathione and adenosine is demonstrated in isolated cell models (rabbit renal tubules and rat liver hepatocytes) of hypothermic preservation and reperfusion and in dog renal transplantation. Glutathione in the UW solution is necessary for the preservation of the capability of the cell to regenerate ATP and maintain membrane integrity. Adenosine in the UW solution provides the preserved cell with substrates for the regeneration of ATP during the reperfusion period following cold storage. The omission of GHS from the UW solution results in poorer renal function in the 48 hr dog kidney preservation-transplant model. The role of other components of the UW solution is discussed including lactobionic acid; other impermeants; and the colloid, hydroxyethyl starch. It is concluded that the development of improved preservation solutions will require a more detailed understanding of the mechanism of injury due to cold storage and, once obtained, solutions more complex than the UW solution may be required for improved long-term storage of organs.     

UW is superior to Celsior and HTK in the protection of human liver endothelial cells against preservation injury.

Celsior solution (CS), a new preservation solution in thoracic organ transplantation, was evaluated for its efficacy in cold preservation of human liver endothelial cells (HLEC) and was compared to University of Wisconsin solution (UW) and histidine-tryptophan-ketoglutarate solution (HTK, Custodiol). HLEC cultures were preserved at 4 degrees C in CS, UW, and HTK, for 2, 6, 12, 24, and 48 hours, with 6 hours of reperfusion. Levels of lactate dehydrogenase (LDH), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and adenosine 5'-triphosphate (ATP) were measured after each interval of ischemia and the respective phase of reperfusion. Preservation injury of HLEC as measured by LDH release, intracellular ATP level, and MTT reduction were overall significantly (P CS > HTK.     

Lazaroid U74389G ameliorates ischemia-reperfusion injury in the rat lung transplant model.

We investigated the effect of Lazaroid U74389G on ischemia-reperfusion injury in the rat orthotopic left lung transplantation model. Five groups of reperfused lungs were studied. In group I, donor lungs were transplanted after 12 hours of preservation in University of Wisconsin (UW) solution at 4C. In groups II, III, and IV, Lazaroid was intravenously administrated at a dose of 1 mg/kg, 8 mg/kg, and 15 mg/kg, respectively, to the donors 30 minutes before preservation and also to the recipients 30 minutes before reperfusion after 12 hours of storage in UW solution at 4C. In group V, Lazaroid was added to the UW solution (80 micromol/l), and also was administered intravenously (6 mg/kg) 30 minutes before reperfusion. After 1 hour of reperfusion, gas exchange function and tissue lipid peroxide levels were significantly improved in Lazaroid-treated groups III, and V compared with no treatment group I. Histologic damage was less severe in groups III, IV, and V than in group I. These findings suggest that Lazaroid U74389G ameliorates ischemia-reperfusion injury in the rat lung transplants by inhibiting lipid peroxidation, regardless of whether it is administrated intravenously or given as an additive to the preservation solution.     

Improved microcirculation by low‐viscosity histidine– tryptophan–ketoglutarate graft flush and subsequent cold storage in University of Wisconsin solution: results of an orthotopic rat liver transplantation model

As previously shown in a model of isolated rat liver perfusion, the combined use of an initial graft flush with low‐viscosity histidine–tryptophan–ketoglutarate (HTK) solution followed by cold storage in University of Wisconsin (UW) solution markedly improved the preservation during an extended cold storage period. In this study, we aimed to transfer our results into an in vivo model of orthotopic rat liver transplantation, and to elucidate the potential mechanism of the improved preservation by focusing on the hepatic microcirculation. Livers were harvested from male Wistar rats. Aortic perfusion with a pressure of 100 cm H₂O was performed with either UW (group UW) or HTK (groups UW and HTK_UW), followed by additional back‐table perfusion with UW (group HTK_UW). After 20‐h cold storage at 4 °C, livers were orthotopically transplanted with reconstructing the hepatic artery. As measured by bile flow and liver enzymes, HTK flush followed by UW storage was superior compared to single use of either UW or HTK solution. The hepatic microcirculation was significantly improved, as shown by the increased percentage of reperfused sinusoids and reduced sinusoidal leucostasis. HTK and UW effectively reduce ischaemia‐reperfusion injury after liver transplantation. By combining the comparative advantages of both solutions, a cumulative effect resulting in an improved preservation was shown. Thus, this mechanism improves microcirculatory reperfusion.     

Fructose 1-6 bisphosphate versus University of Wisconsin solution for rat liver preservation: does FBP prevent early mitochondrial injury?

Background

Fructose 1,6-biphosphate (FBP) has been shown to exert therapeutic effects in models of ischemia-reperfusion in organs other than the liver. This study compared FBP and University of Wisconsin (UW) solution during cold storage and reperfusion, among mitochondria of adult male Wistar rat livers.

Methods

Adult male Wistar rats were assigned to two groups according to the preservation solution used; UW or FBP Aspartate transaminase (AST), alanine transferase (ALT); and lactic dehydrogenase (LDH) were measured in samples of the storage solution obtained at 2, 4 and 6 hours of preservation. After 6 hours of cold storage, we reperfused the liver, taking blood samples to measure AST, ALT, LDH, and throbarbituric acid reactive substances (TBARS). Hepatic fragments were processed for histologic analysis; for determinations of TBARS, catalase, and nitric oxide as well as for mitochondrial evaluation by infrared spectroscopy.

Results

During cold preservation, levels of AST and LDH in the storage solution were lower among the FBP group, but after reperfusion, serum levels of AST, ALT, and LDH were higher in this group, as was catalase activity. TBARS and nitric oxide were comparable between the groups. In the UW group there was a higher amide I/amide II ratio than in the FBP group, suggesting an abnormal protein structure of the mitochondrial membrane. No signs of preservation injury were observed in any liver biopsy, but sinusoidal congestion was present in livers preserved with FBP.

Conclusion

FBP showed a protective effect for preservation during cold storage seeming to protect the mitochondrial membrane although it did not prevent reperfusion injury.     

Relationship between ischemia/reperfusion injury and the stimulus of fibrogenesis in an experimental model: comparison among different preservation solutions

Background and Aims

Orthotopic liver transplantation (OLT) has been the standard treatment for end-stage acute and chronic liver disease. Ischemia-reperfusion (I/R) injury is one of the major causes of poor graft function early after OLT, and adversely influencing graft and patient survivals. It is unknown whether I/R injury influences liver fibrogenesis.

Materials and Methods

Livers from 25 adult male Wistar rats were randomly assigned into 5 experimental groups according to the preservation solution: saline solution (SS); University of Wisconsin (UW) solution; Fructose 1, 6-biphosphate (FBP); S-Nitroso-N-Acetylcysteine (SNAC): or UW + SNAC (SNAC+UW). Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactic dehydrogenase (LDH) were determined in preservation solution samples at 2, 4, and 6 hours. After 6 hours of cold ischemia, ex situ reperfusion was applied to the liver for 15 minutes. Serum AST, ALT, LDH, and renin levels were determined. Fresh liver slices were processed for histological studies, determination of thiobarbituric acid reactive substances, catalase, and glutathione, and expression of TGF-β1 and angiotensin II AT1 receptor.

Results

AST was significantly lower during cold storage with UW than with the older media (P = .001); ALT was lower in the FBP group (P = .023) and LDH was lower in the FBP and SNAC groups (P = .007). After reperfusion, serum AST, ALT, LDH, and TBARS showed no significant differences among the groups. Catalase was significantly lower in the SS and FBP groups (P = .008 and P = .006, respectively). Compared with UW, glutathione concentrations were significantly higher in SS, FBP, and SNAC 200 (P = .004). Renin levels were significantly lower in the FBP group (P = .022). No histological signs of preservation injury were observed in the hepatic sample. No expressions were detected of TGF-β1 or AT1 receptor.

Conclusion

In this experimental model of early reperfusion injury, preservation changes related to higher levels of renin, which suggest its role in fibrogenesis. FBP was associated with lower renin levels than other solutions including UW.     

Prolonged rat pancreas preservation using a solution with the combination of histidine and lactobionate

A newly formulated solution consisting of lactobionate with or without histidine was tested in the preservation of the rat pancreas. Adult male Lewis rats weighing 120–250 g were used as donors and recipients. Fifty-four rat pancreas transplants were performed to investigate the effectiveness of this test solution and to compare it with the standard University of Wisconsin (UW) solution. The final osmolarity of the new test solution was 290–320 mosmol/l. This solution had a higher sodium content and lower potassium content (Na: 110 mEq/l, K: 50 mEq/l). Adenosine, insulin, hydroxyethyl starch and dexamethasone, which are components of the UW solution, were not present in this test solution. Histidine was used as a buffer. Rat pancreases were stored at 4 °C in either standard UW solution, or high-Na ⁺-histidine solution, or high-Na ⁺ -lactobionate solution for 48 h and 72 h prior to heterotopic transplantation into rats with streptozotocin-induced diabetes mellitus. Functional success rates for rats receiving pancreases that had been preserved in high-Na*-histidine and in high-Na ⁺-lactobionate solutions at 4°C were 100% (5/5) and 100% (7/7) after 48 h preservation, and 50% (4/8) and 14% (1/7) after 72 h preservation, respectively. By contrast, standard UW solution gave only a 44% (4/9) success rate after 48 h preservation and a 0% (0/8) success rate after 72 h preservation. These results demonstrated that the high-Na ⁺-histidine solution was superior to standard UW solution for rat pancreas preservation. This was probably due to the buffer, histidine, which prevented the acidosis of ischemic tissue during the period of preservation.     

Cold preservation of the small intestine with the new Celsior-solution

The aim of the present study was to evaluate the potential of Celsior, a recently developed cardioplegic and heart storage solution, to protect the small bowel during ischemic storage. Small bowel segments were isolated from rats, flushed with either UW or Celsior solution, and cold-stored for 18 h at 4 °C in the respective solution. After ischemic storage, some preparations were freeze-clamped for analysis of tissue metabolites while other preparations were tested for structural and functional integrity by isolated perfusion in vitro using a previously validated model. After 18 h of ischemic storage no significant differences were seen between Celsior and UW with regard to the development of edema, energy charge, or creatine phosphate, but lactate accumulation was significantly reduced in the Celsior group, although glucose catabolism was not inhibited. Histological evaluation of the cold-stored organs showed no differences with regard to structural integrity between the two groups. Total vascular resistance upon reperfusion was significantly lower in the Celsior group (666 ± 126 vs 827 ± 88 MPa s m^{–3 *}), as was the intestinal release of LDH (9.7 ± 4.4 vs 18.2 ± 4.6 U/l *). Carbohydrate absorption from the intestinal lumen amounted to venous effluent concentrations of 0.58 ± 0.24 vs 0.18 ± 0.15 mg% ^* of galactose in the Celsior and UW groups, respectively. Within the limits of this in vitro pilot study, Celsior provided better postischemic recovery of the small bowel than UW in terms of vascular perfusion characteristics, enzyme release, and carbohydrate absorption and may, thus, be considered a suitable alternative for intestinal organ preservation. Received: 13 June 1997 Received after revision: 19 September 1997 Accepted: 8 October 1997     

High-Na + low-K + UW cold storage solution reduces reperfusion injuries of the rat liver graft

The isolated perfused rat liver model was used to assess graft viability after 24 h of cold preservation. Two solutions were compared for liver preservation: Belzer's original UW solution (high-K ⁺ UW) and a solution containing the same components but with inverted concentrations of sodium and potassium (high-Na ⁺ UW). During the 120 min of normothermic reperfusion, livers preserved in the high-Na ⁺ UW solution released lower levels of creatine kinase-BB isoenzyme, transaminases (ALT and AST), and potassium than those preserved in the high-K ⁺ UW solution. Bile flow and biliary excretion of indocyanine green increased when livers were preserved in the high-Na ⁺ UW solution. We found no statistical differences for oxygen consumption and tissue ATP concentration. The results of this study support the concept that a high-Na ⁺ UW solution is a more effective means of preserving rat livers, at least after 24 h of cold-storage and 120 min of reperfusion in the isolated perfused model, than the original high-K ⁺ UW solution. Liver preservation in the high-Na ⁺ UW solution reduces damage to sinusoidal endothelial and hepatocellular cells. The use of an extracellular-like Belzer cold storage solution eliminates potassium-related problems in cold preservation and subsequent normothermic reperfusion while keeping all the qualities of the original UW solution. Received: 26 August 1997 Received after revision: 12 November 1997 Accepted: 28 November 1997     

Effect of fructose-1,6-bisphosphate in the cold storage solution after 12 and 36 hours of rat liver preservation

Fructose-1,6-bisphosphate (FBP) has been reported to have a protective effect on liver injury following ischemic/reperfusion periods because it maintains ATP levels during cold preservation. In the present study, we evaluated the effects of addition of FBP to storage solutions for cold liver preservation during 12 or 36 hours. Adult male Wistar rats were randomly divided into three experimental groups. The hepatic perfusion and preservation were performed with these solutions: UW; UW plus 10 mmol/L FBP; and FBP 10 mmol/L (FBPS) alone. The biochemical measurements of AST and ALT were performed on samples of the cold storage solution after 12- or 36-hour preservation. UW and FBPS solutions showed similar preservation grades at 12 hours. Addition of 10 mmol/L of FBP to UW solution induced liver injury and a poor preservation grade during 12 or 36 hours. UW solution was better than FBPS after 36 hours preservation. UW solution continues to offer a superior performance for liver preservation during long times; however, FBPS may be an alternative for short cold preservation times.     

Evaluation of UW solution in a rat kidney preservation model. I. Effect of hydroxyethyl starch and electrolyte composition.

Preservation of rat kidneys by simple ice-storage has been demonstrated after 48 hr using the University of Wisconsin (UW) solution; hypothermic preservation of the rat kidney was dramatically improved. A modified UW solution without hydroxyethyl starch (HES) also gave uniform survival after 48 hr of storage, and even better function and morphology. Substitution of HES from another source also improved renal function when compared with UW (Dupont) and it is suggested that prolonged storage of UW solution prior to use may reduce its effectiveness. Reversing the Na:K ratio of the solution still allowed successful preservation, but significantly worsened morphology of the surviving kidney.     

Luminal preservation of rat small intestine with University of Wisconsin or Celsior solution

AIMS: Luminal administration of a preservation solution that prevents mucosal injury may decrease posttransplant complications. However, luminal administration of University of Wisconsin solution (UW) is controversial. In this study, we examined the potential of Celsior as a luminal small bowel preservation solution in comparison to UW or UW enriched with glutamine. METHODS: Small bowels of six normal WagRij rats were excised and divided into six equal segments. Each segment was luminally flushed with 10 mL ice-cold UW, UW with glutamine (20 g/L) or Celsior, and stored for 0, 2.5, and 24 hours at 4 degrees C. LDH, glucose, and lactate concentrations were determined in the preservation solutions. Histologic changes were determined using the Park score. RESULTS: Lactate dehydrogenase (LDH) was increased in all solutions after 2.5- and after 24-hour preservation. However, LDH was lower in Celsior than UW and UW with glutamine. Furthermore, higher glucose and lactate levels were found after 2.5- and 24-hour preservation in UW and UW with glutamine compared to Celsior. Histologically, jejunal segments were more susceptible to preservation than ileal segments, irrespective of the preservation solution used. Mucosal injury was evident after 2.5 hours (Park Scale 0-3) and increased significantly after 24 hours (park scale 3-6). CONCLUSIONS: Based on the lower glucose, lactate, and LDH levels in small intestines stored in Celsior, this study suggests that Celsior is a better luminal preservation solution than UW. Unfortunately, histological evaluations still show severe mucosal injury, indicating that there is a need for better luminal preservation solutions or for concomittant intravascular delivery of a preservation solution.     

The enhancement of cellular cAMP with olprinone protects autotransplanted rat kidney against cold ischemia-reperfusion injury

The administration of a cyclic nucleotide analog improves cold ischemia/reperfusion injury in several organs. The type 3 phosphodiesterase inhibitor olprinone is a potent stimulus that enhances cellular cAMP levels. The present study was performed to investigate the protective effects of enhanced intracellular cAMP levels by olprinone in rat orthotopic kidney transplantation. Autotransplantation and immediate contralateral nephrectomy were performed in Lewis rats after 18 hours of graft storage at 4 degrees C in University of Wisconsin (UW) solution with or without 25 microg/mL olprinone hydrochloride. At 2 hours after reperfusion, serum and urinary biochemical indicators of renal dysfunction and injury were measured: serum creatinine, fractional excretion of Na+ and urinary N-acetyl-D-glucosaminidase. Additionally, intracellular cAMP in kidney tissues was measured by a radioimmunology method. Compared to the only UW solution group, olprinone hydrochloride significantly reduced the increased in serum creatinine, FENa and NAG caused by renal ischemia/reperfusion injury, after 2 hours of reperfusion. The content of cAMP at the endpoint of 18 hours cold preservation was significantly greater in the UW plus olprinone hydrochloride group than that in the UW group. Two hours after reperfusion, the content of cAMP in the UW plus olprinone hydrochloride group was still significantly higher than that in the UW group without containing olprinone hydrochloride. These results support a beneficial effect of olprinone against cold ischemia and reperfusion injury via an increased intracellular cAMP levels.     

Fate of hepatocyte and sinusoidal lining cell function and kinetics after extended cold preservation and transplantation of the rat liver

We investigated the chronological profile of graft damage and recovery after liver cold ischemia-reperfusion (I/R) injury, with particular attention to the role of apoptosis on hepatocyte and sinusoidal endothelial cell (SEC) damage. Male Lewis rats underwent rearterialized orthotopic liver transplantation using grafts subjected to a short (University of Wisconsin [UW] solution for 1 hour [UW1h]) and prolonged period (UW16h) of cold preservation. Experiments were performed immediately after preservation and 4 hours, 24 hours, 3 days, and 7 days after reperfusion. At each time, graft function, incidence of apoptotic cells, expression of the epitope recognized by a monoclonal antibody specific to rat SECs (SE-1), and incidence of proliferating cells were estimated. In the UW16h group, the proportion of apoptotic SECs was markedly elevated at 4 hours. The incidence of hepatocyte apoptosis was very low, although massive hepatocyte necrosis was evident at 24 hours. The incidence of proliferating hepatocytes and SECs peaked at 3 days, then returned to normal by 7 days. SE-1 expression was reduced immediately after preservation, followed by a marked reduction at 4 and 24 hours after reperfusion, and expression returned to normal by 7 days. Although SEC apoptosis was induced in the early phase of cold I/R injury, hepatocyte damage developed without the occurrence of apoptosis. Regeneration of both hepatocytes and SECs after cold I/R injury peaked at 3 days and was complete by 7 days, whereas functional recovery of these cell populations was complete 3 days after reperfusion. (Liver Transpl 2002;8:370-381.)     

Influence of Pituitary Adenylate Cyclase-Activating Polypeptide on the Activation of Mitogen Activated Protein Kinases Following Small Bowel Cold Preservation

Cold preservation prior to small bowel transplantation can moderate tissue oxidative injury. This stress triggers several intracellular pathways via mitogen activated protein (MAP) kinases. MAP kinases include the extracellular signal related kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAP kinase. Pituitary adenylate cyclase-activating polypeptide (PACAP) plays a central role in intestinal physiology. We sought to investigate the effect of PACAP on the activation of MAP kinases during cold preservation of the small bowel. Total orthotopic intestinal autotransplantation was performed on 40 Wistar rats. Perfused grafts were stored in University of Wisconsin (UW) solution for 1 (GI), 2 (GII), 3 (GIII), or 6 hours (GIV) without or with 30 PACAP, namely 1 (GV), 2 (GVI), 3 (GVII), or 6 hours (GVIII). After 3 hours of reperfusion in all groups, the activation of MAP kinases were measured using immunocytochemistry of small bowel tissue. Among the UW preserved grafts (GI-GIV), phosphorylated ERK1/2 level were decreased, while phosphorylated JNK1/2 and p38 MAP kinase activation were elevated compared with control levels. In GV-GVIII PACAP we observed enhanced phospho-ERK1/2 appearance with decreased JNK and p38 MAP kinase activity at the end of the reperfusion periods. We concluded that cold preservation decreased phosphorylated ERK1/2 levels and increased JNK1/2 and p38 MAP kinase activities, which meant that cold storage triggered apoptotic cell death. In contrast, PACAP treatment induced signalling pathways protective against oxidative injury by MAP kinases in bowel tissue.     

The impact of liver preservation in HTK and UW solution on microcirculation after liver transplantation

Severe microcirculatory disturbances due to endothelial cell damage and leukocyte adherence during reperfusion of transplanted livers are considered to contribute to early graft failure. Since the degree of reperfusion injury after liver transplantation depends on the length of preservation time and the solution used for preservation, the aim of our study was to assess three solutions with respect to microvascular perfusion and leukocyte adhesion. Therefore, rat livers were stored up to 24 h in Euro-Collins (EC), University of Wisconsin (UW), or histidin-tryphtophan-ketoglutarate (HTK) solutions prior to orthotopic transplantation. The livers were studied in situ 60 min postoperatively using intravital fluorescence video microscopy. Using simple syringe flushing (10 ml), sinusoidal perfusion decreased below 50% in EC preserved livers after 8 h preservation, in HTK preserved livers after 16 h preservation, and remained higher than 70% in livers preserved in UW up to 24 h. Permanent adhesion of leukocytes was increased more rapidly in organs after 1, 8, 16, and 24 h preservation in HTK (16%, 15%, 34%, and 49.7% ± 4.7%) compared to those preserved in UW (15%, 18%, 17%; and 32.7% ± 3.3%; P < 0.05). Using a 10-fold volumn of the organ weight of HTK solution during the harvesting procedure, with an 8 min equilibration period, sinusoidal perfusion (39.6 ± 4.7%) and leukocyte adhesion (42.7 ± 3.1%) were not improved after 24 h. In contrast, equilibration with a volumn of approximately 40-times the liver weight improved sinusoidal perfusion (70.8% ± 2.7%; P < 0.01) and leukocyte adhesion (24.9% ± 3.1%; P < 0.01) significantly. Thus, using HTK solution, simple flushing prior to long-term cold storage resulted in microcirculatory disturbances when compared to UW solution. Larger volumns of HTK solution with an additional equilibration period of 8 min, however, reduced leukocyte adhesion and improved sinusoidal perfusion to a similar degree as UW solution.     

A new dextran 40-based solution for liver preservation.

UW solution is at present the most efficient solution for preservation of livers for transplantation. We have developed an alternative solution based on dextran instead of hydroxyethyl starch and without raffinose, allopurinol, magnesium sulfate, insulin, penicillin, or dexamethasone, which all are used in UW solution. In addition, 62.5 mM potassium in UW solution is replaced with sodium. We tested this new solution for liver preservation using the isolated perfused rabbit liver. We found that livers preserved in the UW solution for 24 or 48 hr lost 11.6 +/- 2.6% and 16.8 +/- 2.0% of the prepreservation weight, respectively, as a sign of organ shrinkage (P less than 0.001). In contrast, no change in liver weight was observed after preservation in the new dextran-based solution. Similarly, no change in total tissue water of the rat liver slices was seen after preservation in the new solution. Furthermore, livers preserved for 24 hr in the UW solution or the new solution produced the same amount of bile as unpreserved livers. However, after preservation in the UW solution for 48 hr, bile production was reduced by 65% (P less than 0.05). In contrast, livers preserved for 48 hr in the new solution showed no reduction in bile production. We conclude that our new solution significantly improves long-term liver preservation, and with this modified solution, 48-hr preservation may be safe.