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The first case of domino liver transplantation from a brain-dead donor in Japan is described. A 49-year-old man with familial amyloidotic polyneuropathy received a cadaver liver, and his native liver was transplanted into a 53-year-old man with polycystic liver and kidney disease. The cadaveric liver allograft was transplanted by the conventional technique. The graft taken from the first recipient had four outflow orifices (the left, middle, and right hepatic veins, and upper vena cava), for which a single orifice was created at the back table. This graft was transplanted in piggy-back fashion. The first recipient developed acute rejection on day 13 and hepatic artery stenosis on day 36. These were treated by steroid recycle therapy and percutaneous transarterial angioplasty. He was discharged on day 57 with normal liver function. The second recipient underwent re-operation for bleeding from the right adrenal gland and left thoracic cavity. He was diagnosed with acute rejection on day 7, which was treated by steroid pulse therapy. He was discharged uneventfully on day 39 with normal liver function.

Three different types of treatment were conducted to clarify the properties of a novel immunomodulator, FTY720, in canine kidney allograft models. Survival, biochemical and hematological tests, pharmacokinetics, and histopathology of grafts and extra-renal organs were analyzed. Accompanying a remarkable reduction in circulating lymphocytes, single-drug treatment of FTY720, ranging from 0.05 to 10 mg/kg, exhibited significant prolongation of graft survival without a dose-dependent effect. Short-course induction with FTY720 at 5 mg/kg per day exhibited similar anti-rejection effects as did single-drug treatment but no advantage in rescuing ongoing rejection. In combination with cyclosporine (CsA; 5 mg/kg) or tacrolimus (FK; 0.5 mg/kg), FTY720 had an additive effect. Trough blood concentrations of FTY720 were linearly correlated with dose. No animal showed critical adverse effects at any point. FTY720 holds promise as a candidate in a new category of drugs that can be combined with conventional agents for induction and maintenance immunosuppression in clinical organ transplantation.

Background Adenosine, a metabolite of adenosine triphosphate degradation during ischemia, is reported to attenuate ischemia and reperfusion injury in several tissues. Dipyridamole is a nucleoside transport inhibitor that augments endogenous adenosine. In this study, we tested whether dipyridamole would attenuate hepatic I/R injury. For this purpose, dipyridamole was applied to a 2-hour total hepatic vascular exclusion model in dogs. Study design Dipyridamole (DYP) was given by continuous intravenous infusion for 1 hour before ischemia at a dose of 0.25 mg/kg (high-DYP, n=6), 0.1 mg/kg (medium-DYP, n=6), or 0.05 mg/kg (low-DYP, n=6). Nontreated animals were used as ischemic controls (CT, n=12). Two-week survival, systemic and hepatic hemodynamics, liver function tests, energy metabolism, adenosine 3′, 5′-cyclic monophosphate (cyclic AMP) levels, platelet numbers, arachidonic acid metabolites, and histopathology were analyzed. Results Two-week animal survival was 25% in CT, 17% in high-DYP, 100% in medium-DYP, and 17% in low-DYP. Dipyridamole significantly improved postreperfusion hepatic blood flow and energy metabolism, attenuated liver enzyme release and purine catabolite production, and augmented cyclic AMP levels. The medium dose of dipyridamole lessened platelet aggregation, thromboxane B2 production, and polymorphonuclear neutrophil infiltration, and improved survival. Conclusions We demonstrated marked hepatoprotective effects of dipyridamole against severe ischemia and reperfusion injury in canine livers. Dipyridamole is a promising agent for liver surgery and transplantation.

症例は38歳女性. 亜急性型劇症肝炎で生体肝移植の適応評価のため当科に転院しICU管理となった. 高容量持続的血液透析濾過と血漿交換を併用する保存的治療を行ったが, 入院10日目に発症した上行結腸破裂に対し右半結腸切除術を行い回腸に人工肛門を増設した. その後肝機能は順調に回復し入院30日目で一時退院, 5カ月後に再入院し人工肛門を閉鎖し現在社会復帰している. 切除した結腸の穿孔部は虚血性腸炎の病理診断を得た. 亜急性型劇症肝炎の保存的治療中に虚血性腸炎による大腸穿孔の報告はなく, その臨床経過と大腸穿孔の原因に考察を加え報告した.

Background. A Rho-ROCK signal system induces vascular contraction and neutrophil migration, both of which are characteristic features found with ischemia and reperfusion injury of the liver. We tested our hypothesis that a novel ROCK I inhibitor, Y-27632, attenuates hepatic ischemia and reperfusion injury. Methods. Rats underwent 70% partial hepatic ischemia for 120 minutes and subsequent reperfusion. Y-27632 of 10mg/kg was given orally 1 hour before ischemia, while distilled water was given to the control animals. One week animal survival, systemic hemodynamics, hepatic tissue blood flow, liver function tests, plasma endothelin-1, serum hyaluronic acid levels, myeloperoxidase activity and malondialdehyde level in liver tissue, membrane attack complex-1 and intracellular adhesion molecule-1 staining, and histological architecture were analyzed. Results. Y-27632 prolonged 1-week animal survival from 25% of untreated animals to 75% accompanied with significant amelioration of hepatic tissue blood flow, liver function tests and histological architecture without any adverse effects on systemic hemodynamics. In addition, plasma endothelin-1 and serum hyaluronic acid levels decreased markedly compared to the control, concomitant with remarkable suppression of membrane attack complex-1 stain positive neutrophils infiltration, myeloperoxidase activity and malondialdehyde level. Conclusion. Present study suggests that activation of a Rho-ROCK signal system is associated with ischemia and reperfusion injury of the liver, and that Y-27632 may be an attractive agent for application in major liver resection using temporary inflow occlusion and hepatic preservation.

Background. Leflunomide and its metabolite, A77 1726, interfere with pyrimidine metabolism and exert potent immunosuppression in experimental organ transplantation. However, clinical use of the agents has been restrained because of an extended half-life. FK778, one synthetic malononitrilamide derived from A77 1726, is synthesized to overcome this problem while maintaining similar therapeutic efficacy. Methods. Immunosuppressive effect, pharmacokinetics, and adverse events of FK778, as a single drug treatment or combination with tacrolimus or cyclosporine, were determined in a canine kidney transplantation model. The agents were daily administered orally to the animals for 90 days after surgery. Animal survival, pharmacokinetics, biochemistry, hematology, and histopathology were evaluated. Results. FK778 at 4 mg/kg prolonged median survival of the control animals from 10 days to 30.5 days. Administration of 4 mg/kg FK778 with 0.3 mg/kg tacrolimus or 10 mg/kg cyclosporine increased median survival to 75.5 days and 50.5 days, respectively. In combined treatments, trough levels of FK778 at 4 mg/kg ranged between 40 μg/mL and 100 μg/mL after 1 month. Vomiting and diarrhea were common in animals given FK778. Bone marrow suppression was seen at higher doses. Conclusions. FK778 is a promising new immunosuppressant that may be used in combination with current standard drugs in organ transplantation. (Surgery 2002;132:72-9.)

Background. In a series of canine liver ischemia experiments, we have shown that amelioration of hepatic injury is achievable by the inhibition of vasoconstriction, cytokine production, platelet aggregation, and neutrophil infiltration. Cyclic adenosine diphosphate (cAMP) was considered to be involved in most of these events. In our study, we tested our hypothesis that augmentation of endogenous cAMP by phosphodiesterase (PDE) 3 inhibitor, amrinone (AM), or adenylate cyclase stimulator, NKH477 (NKH), could attenuate ischemia and reperfusion injury of the liver. Methods. Thirty-six beagle dogs were used. They were divided into group CT (untreated control), group AM, group NKH, and group CB (treated by both agents). AM or NKH were administered i.v. 1 hr before ischemia (group preAM and group preNKH) or 15 min before reperfusion (pos-AM and postNKH). Combination group animals were treated only before ischemia. Animal survival, hepatic tissue blood flow, liver enzymes, platelet counts, energy metabolism, hepatic cAMP and cyclic guanosine 3',5'-cyclic monophosphate levels, and histopathology were analyzed. Results. Two-week animal survival was significantly improved by pre- or posttreatment with either agent. After reperfusion, hepatic tissue blood flow, liver enzyme release, platelet counts, energy metabolism, tissue cAMP levels, and histological architecture were also ameliorated markedly. Combination of both agents induced severe liver damage and lethal hypotension. AM treatment exhibited more protective effects than NKH, particularly when it was given before ischemia. Interestingly, not only cyclic guanosine 3',5'-cyclic monophosphate, were also restored at higher levels after reperfusion by preischemia treatment. Conclusions. Administration of amrinone or NKH477 maintained hepatic tissue concentrations of cyclic nucleotides, and attenuated ischemia and reperfusion injury of the liver. Thus, regulation of hepatic tissue cyclic nucleotides is an important alternative for prevention of hepatic damage in liver preservation and surgery.

Background. Membrane phospholipid breakdown, caused by ischemia and reperfusion (I/R) of the liver, releases free fatty acids including arachidonic acids and lysophospholipids, which serve as precursors of various inflammatory lipid derivatives. Phospholipase A 2 (PLA2) is a key enzyme that initiates this reaction. In this study, we tested our hypothesis that a type II PLA 2 inhibitor, LY329722, could attenuate hepatic I/R injury caused by a 2-hr total hepatic vascular exclusion (THVE) in dogs. Methods. Eighteen beagle dogs, subjected to a 2-hr THVE, were divided into three groups. Group 1 (n56) was untreated and served as a control group. LY329722 was administered to animals in group 2 (n56) intravenously (0.2 mg·kg 21 ·hr 21 ) for 60 min before ischemia, and to animals in group 3 (n56) for 60 min starting 15 min before reperfusion (0.2 mg·kg 21 ·hr 21 ). Animal survival, systemic and splanchnic hemodynamics, hepatic tissue blood flow, liver functions, energy metabolism, hepatic venous thromboxane B 2 and endothelin-1 levels, phospholipid levels and tumor necrosis factor-a mRNA expression in liver tissue, and histopathologic findings were evaluated. Results. Two-week animal survival was 33% (two of six) in group 1, and 100% (six of six) in groups 2 and 3. LY329722 improved systemic and splanchnic hemodynamics, hepatic tissue blood flow, and energy metabolism, reduced liver enzyme, thromboxane B 2, and endothelin-1 release, prevented hepatic phospholipid degradation and tumor necrosis factor-a mRNA expression, and lessened histopathologic damage and the number of neutrophil infiltrating into the liver tissue. Conclusion. The present study demonstrated that a type II PLA 2 inhibitor, LY329722, attenuated hepatic I/R injury caused by a 2-hr THVE model in dogs. Phospholipase A 2 (PLA2) accelerates breakdown of membrane phospholipids of the heart, liver, and kidney under warm ischemia (1‐3), and leads to the release of free fatty acids including arachidonic acid, and lysophospholipids. The arachidonic acids are metabolized via the cyclooxygenase pathway to thromboxane (TX) A 2 and prostaglandins (PGs), or via 5-lipoxygenase pathway to leukotrienes. Lysophospholipids are metabolized to platelet-activating factor (PAF) by acetyltransferase. Most of these lipid derivatives have proinflammatory and vasoconstrictive actions and contribute to postischemic organ dysfunction, which is attenuated by nonspecific PLA 2 inhibitors ( 4‐6 ). PLA 2 is classified generally into two subtypes: cPLA2 and sPLA 2 (7). cPLA2 is involved in the breakdown of membrane phospholipids of intracellular organelles. Of the secretory PLA 2 (sPLA2), type I PLA2 is contained in the exocrine pancreas and type II PLA 2 is involved in inflammatory events, particularly the ischemia and reperfusion (I/R) injury of the heart, liver, kidney, and intestine (8 ‐11). LY329722 is a novel selective type II PLA 2 inhibitor (12), which is derived from synthetic LY315920/S-5920 (13). In this study, we tested whether LY329722 could attenuate hepatic I/R injury caused by a 2-hr total hepatic vascular exclusion (THVE) in dogs.

Background. Microcirculatory disturbance has been shown to play a critical role in hepatic ischemia and reperfusion (I/R) injury. Angiotensin II (AngII) is one of the most potent endogenous vasoconstrictors. Angiotensin II type I (AT 1 ) receptor antagonist has been reported to have protective effects on I/R injury of the heart and kidney. However, effect on hepatic I/R injury has not been determined. In this study, we investigate our hypothesis that AT 1 receptor antagonist, CV-11974, attenuates hepatic I/R injury. Methods. Twelve beagle dogs underwent a 2-hr total hepatic vascular exclusion with veno-venous bypass. CV-11974 was given to animals at a dose of 0.002 mg/ kg/min for 5 min followed by 0.001 mg/kg/min for 25 min via portal vein before ischemia (group II, n=6). Nontreated animals were used as the control (group I, n=6). Animal survival, hemodynamics, hepatic tissue blood flow (HTBF), liver function, platelet count, renin activity, and AngII concentration of hepatic vein, energy metabolism, and histopathology were analyzed. Results. Two-week survival was 33% in group I, in contrast, 100% in group II. Mean arterial blood pressure during early reperfusion was maintained, and HTBF after reperfusion was significantly higher in group II. Treatment attenuated liver enzyme release and decrease of platelet count, increased renin and AngII, suppressed ATP degradation during ischemia and enhanced ATP resynthesis after reperfusion. Neutrophil infiltration and histopathological damages were lessened in group II. Conclusions. Our data demonstrated that the local renin-angiotensin system might play a role in hepatic microcirculation. AT 1 receptor blockade with CV-11974 attenuated hepatic microcirculatory disturbance and ameliorated I/R injury.

Background: Prostaglandin has been reported to have protective effects against liver injury. Use of this agent in clinical settings, however, is limited because of drug-related side effects. This study investigated whether misoprostol, prostaglandin E 1 analogue, and OP-41483, prostaglandin I 2 analogue, which have fewer adverse effects with a longer half-life, attenuate ischemic liver damage. Study Design: Thirty beagle dogs underwent 2 hours of hepatic vascular exclusion using venovenous bypass. Misoprostol was administered intravenously for 30 minutes before ischemia and for 3 hours after reperfusion. OP-41483 was administered intraportally for 30 minutes before ischemia (2 μg/kg/min) and for 3 hours after reperfusion (0.5 μg/kg/min). Animals were divided into five groups: untreated control group (n = 10); high-dose misoprostol (total 100 μg/kg) group (MP-H, n=5); middle-dose misoprostol (50 μg/kg) group (MP-M, n=5); low-dose misoprostol (25 μg/kg) group (MP-L, n=5); and OP-41483 group (OP, n=5). Animal survival, hepatic tissue blood flow (HTBF), liver function, and histology were analyzed. Results: Two-week animal survival rates were 30% in control, 60% in MP-H, 100% in MP-M, 80% in MP-L, and 100% in OP. The treatments with prostaglandin analogues improved HTBF, and attenuated liver enzyme release, adenine nucleotrides degradation, and histologic abnormalities. In contrast to the MP-H animals that exhibited unstable cardiovascular systems, the MP-M, MP-L, and OP animals experienced only transient hypotension. Conclusions: These results indicate that misoprostol and OP-41483 prevent ischemic liver damage, although careful dose adjustment of misoprostol is required to obtain the best protection with minimal side effects.

Hepatic grafts from non-heartbeating donors may alleviate the organ shortage, but they inherently suf­ fer from warm ischemia. In the present study, we tested our hypothesis that augmentation of endoge­ nous adenosine by inhibition of nucleoside transport with R75231 attenuates ischemic liver injury. Adult female beagle dogs underwent 2·hr hepatic vascular exclusion with venovenous bypass. R75231 was given to the animals by continuous intravenous infusion for 30 min before ischemia at a dose of 0.1 mg/kg (Group 2, n=6), 0.05 mg/kg (Group 3, n=6), or 0.025 mg/kg (Group 4, n=6). Nontreated animals were used as the control (Group 1, n=10). Animal survival, hepatic tissue blood tlow, liver function, and histopathology were ana­ lyzed. Two-week animal survival was 300/0 in Group 1, 88% in Group 2, 100% in Group 3, and 100% in Group 4. Postreperfusion hepatic tissue blood tlow was mark· edly improved by the treatment. Treatment signifi. cantly attenuated liver enzyme release, lipid peron­ dation, and changes in adenine nucleotides and purine catabolites. Structural abnormality of the liver after reperfusion was markedly improved by R75231 treatment, showing better architecture and less neu· trophil infiltration. Preischemic administration of a nucleoside transport inhibitor ameliorated ischemic liver injury due to the positive effects of augmented endogenous adenosine, and is applicable clinically when the liver is procured from a controlled non­ heartbeating donor. Liver ischemia causes progressive degradation of adeno­ sine triphosphate (ATP),* leading to an immense accumula­ tion of purine catabolites in ischemic tissues_ Adenosine, one of the intermediary products of the degradation cascade, has been known to exert various biological actions (5-10) such as increased blood flow, vasodilation, inhibition of free radical production, suppression of neutrophil activation, and preven­ tion of platelet aggregation. Upon reoxygenation, adenosine becomes an important substrate for ATP resynthesis. How­ ever, adenosine is rapidly deaminated into inosine during ischemia and transported out of the ischemic tissues after reperfusion, thereby depriving ischemic tissues of ade­ nosine's beneficial effects. In this study, in an attempt to establish a strategy for the use of livers from non-heartbea.t­ ing donors, we first tested our hypothesis that augmentation of endogenous adenosine by inhibiting its transport with a nucleoside transport inhibitor, R75231, attenuates warm ischemic liver injury, using a 2-hr total hepatic vascular exclusion model.

Controversy persists as to whether reperfusion-induced injuries actually occur in the hepatocyte. The liver is the major source of glutathione, a scavenger of hydrogen peroxide. The aim of this study was to evaluate the sensitivity of the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG) [GSH: GSSG] as an index of hepatic metabolic stress. A total of 121 rats were studied. The superior mesenteric vein (SMV) was occluded for 30 min, and this was followed by 0, 10, or 120 min of reperfusion. Total glutathione and GSSG levels in the liver, bile, and plasma were quantified, using glutathione reductase-coupled enzymatic assays. Results indicated that the hepatic GSH/GSSG ratio was maintained after an occulusion of the SMV, despite a decrease in adenosine triphosphate (ATP) level and energy charge potential. However, plasma levels of total glutathione and GSSG in the inferior vena cava increased after SMV occlusion and continued to increase after reperfusion. Biliary GSSG efflux decreased during 30-min occlusion of the SMV, and remained low even after reperfusion. The liver maintains homeostasis despite a decrease in biliary GSSG efflux, probably by secreting excess GSSG into the hepatic vein when the SMV is occluded. We conclude that the total amount of glutathione and GSSG in the plasma is directly correlated with oxidative stress in the liver.

The effects of intravenous bolus injection of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) on hepatic mitochondrial energy metabolism were investigated in rats. The rats were injected with 15 micrograms/kg body wt of human recombinant TNF-alpha and IL-1 beta. The hepatic energy charge decreased to 0.794 +/- 0.005 and 0.789 +/- 0.006 in comparison with the sham control value of 0.838 +/- 0.007 and 0.835 +/- 0.011 at 12 and 24 hr after the treatment. The mitochondrial redox state (NAD+/NADH) increased from 17.4 +/- 1.9, 16.6 +/- 1.4, and 19.2 +/- 2.1 to 33.5 +/- 3.5, 27.8 +/- 2.8, and 30.9 +/- 2.6 concomitant with an increase in arterial blood ketone body ratio (acetoacetate/beta-hydroxybutyrate) from 0.49 +/- 0.04, 0.34 +/- 0.04, and 0.44 +/- 0.09 to 1.00 +/- 0.16, 0.69 +/- 0.13, and 0.86 +/- 0.15 at 3, 12, and 24 hr after the treatment. Total ketone body concentration in liver tissue and arterial blood was significantly lower at 24 hr after the treatment. State 3 respiration rate of isolated mitochondria increased by 29.2, 30.3, and 19.2% concomitant with an increase in oxidative phosphorylation rate by 26, 33.7, and 24.3% at 3, 12, and 24 hr after the treatment. These results showed that the administration of TNF-alpha and IL-1 beta in rats induced a hypermetabolic state in hepatic mitochondrial energy metabolism, which is a pattern similar to sepsis and presumably a compensatory reaction to the increased energy consumption.

Insulin and glucagon have opposite effects on various hepatic functions, including energy metabolism, which is essential for hepatic viability. To evaluate the effects of insulin and glucagon on the recovery of graft liver function, changes in these levels were investigated in relation to arterial ketone body ration (AKBR) during a 30-h period after graft liver reperfusion in 29 recipients of living related liver transplants. Insulin levels did not change significantly throughout this study, while glucagon levels decreased immediately after reperfusion, indicating a rapid degradation of glucagon by the graft liver. The insulin/glucagon (I/G) ratio increased after reperfusion concomitantly with AKBR. In addition, the I/G ratio was significantly correlated with AKBR after reperfusion. It is concluded that the increase in the I/G ratio was closely related to the recovery of graft liver function as reflected by the AKBR in living related liver transplantation.

Background Cold ischemia-reperfusion (I/R) injury is a prominent cause of delayed graft function after kidney transplantation. Reactive oxygen species play a crucial role in I/R injury. Edaravone is a synthetic radical scavenger that has been used in acute stroke. Some animal experiments have revealed its beneficial effects against I/R injury, but its effects after cold preservation and transplantation of canine kidneys are unknown. Methods Female hybrid dogs weighing 11 to 13 kg were used. Under anesthesia, the left kidney was harvested. After 72 hr of preservation in cold histidine-tryptophan-ketoglutarate solution, autotransplantation was performed in the right iliac fossa, with contralateral nephrectomy. Animals were divided into control and treatment groups (n=6 per group). In the treatment group, edaravone was administered intravenously at harvest and at reperfusion (3 mg/kg) and in addition was added to the preservation solution (50 microM). Results Animal survival at 2 weeks was four of six in the control group and six of six in the treatment group. Compared with controls, treated animals had higher mean urine output, higher mean glomerular filtration rate, improved tubular cell function, lower mean serum creatinine, and lower renal vascular resistance. Biopsy specimens from treated animals showed less tubular cell damage and decreased P-selectin expression in endothelial cells. Lipid peroxidation of renal tissue and urinary excretion of 8-hydroxy-2'-deoxyguanosine were suppressed by the treatment. Conclusions Edaravone reduced cold I/R injury in canine renal transplantation. The agent has the potential to ameliorate preservation injury in clinical transplantation.

Liver regeneration in living-donor liver transplantation is summarized from the authors' data. In donors, liver function tests recovered to within the normal range 2 weeks after surgery regardless of graft type. At 2 weeks, the volumetric recovery of the remnant liver was 65% and 80% of the original volume in right and left lobe donors, respectively. These results suggest that functional recovery occurs earlier than morphologic restoration in donors. In recipients, the factor that affected the regeneration rate in size 4 weeks after transplantation was only implanted graft size; the rate was greater in patients in whom smaller grafts were implanted. In recipients with a rate of two or more, however, high portal vein pressure and flow were observed. Further, persistent low platelet counts and hyperbilirubinemia were seen in those patients. These results indicate that size enlargement may be caused by engorgement, and functional recovery is not achieved concurrently with morphologic restoration, especially in patients with smaller grafts. In patients with fulminant hepatic failure who receive auxiliary partial orthotopic liver transplantation, sequential histopathologic observations of the diseased liver revealed that liver regeneration initiates from cytokeratin 17-positive ductules and at least 1 year is necessary for complete recovery.

Adenosine, a metabolite of adenosine triphosphate degradation during ischemia, is reported to attenuate ischemia and reperfusion injury in several tissues. Dipyridamole is a nucleoside transport inhibitor that augments endogenous adenosine. In this study, we tested whether dipyridamole would attenuate hepatic I/R injury. For this purpose, dipyridamole was applied to a 2-hour total hepatic vascular exclusion model in dogs.Dipyridamole (DYP) was given by continuous intravenous infusion for 1 hour before ischemia at a dose of 0.25 mg/kg (high-DYP, n = 6), 0.1 mg/kg (medium-DYP, n = 6), or 0.05 mg/kg (low-DYP, n = 6). Nontreated animals were used as ischemic controls (CT, n = 12). Two-week survival, systemic and hepatic hemodynamics, liver function tests, energy metabolism, adenosine 3', 5'-cyclic monophosphate (cyclic AMP) levels, platelet numbers, arachidonic acid metabolites, and histopathology were analyzed.Two-week animal survival was 25% in CT, 17% in high-DYP, 100% in medium-DYP, and 17% in low-DYP. Dipyridamole significantly improved postreperfusion hepatic blood flow and energy metabolism, attenuated liver enzyme release and purine catabolite production, and augmented cyclic AMP levels. The medium dose of dipyridamole lessened platelet aggregation, thromboxane B2 production, and polymorphonuclear neutrophil infiltration, and improved survival.We demonstrated marked hepatoprotective effects of dipyridamole against severe ischemia and reperfusion injury in canine livers. Dipyridamole is a promising agent for liver surgery and transplantation.

In a series of canine liver ischemia experiments, we have shown that amelioration of hepatic injury is achievable by the inhibition of vasoconstriction, cytokine production, platelet aggregation, and neutrophil infiltration. Cyclic adenosine diphosphate (cAMP) was considered to be involved in most of these events. In our study, we tested our hypothesis that augmentation of endogenous cAMP by phosphodiesterase (PDE) 3 inhibitor, amrinone (AM), or adenylate cyclase stimulator, NKH477 (NKH), could attenuate ischemia and reperfusion injury of the liver.Thirty-six beagle dogs were used. They were divided into group CT (untreated control), group AM, group NKH, and group CB (treated by both agents). AM or NKH were administered i.v. 1 hr before ischemia (group preAM and group preNKH) or 15 min before reperfusion (pos-AM and postNKH). Combination group animals were treated only before ischemia. Animal survival, hepatic tissue blood flow, liver enzymes, platelet counts, energy metabolism, hepatic cAMP and cyclic guanosine 3',5'-cyclic monophosphate levels, and histopathology were analyzed.Two-week animal survival was significantly improved by pre- or posttreatment with either agent. After reperfusion, hepatic tissue blood flow, liver enzyme release, platelet counts, energy metabolism, tissue cAMP levels, and histological architecture were also ameliorated markedly. Combination of both agents induced severe liver damage and lethal hypotension. AM treatment exhibited more protective effects than NKH, particularly when it was given before ischemia. Interestingly, not only cyclic guanosine 3',5'-cyclic monophosphate, were also restored at higher levels after reperfusion by preischemia treatment.Administration of amrinone or NKH477 maintained hepatic tissue concentrations of cyclic nucleotides, and attenuated ischemia and reperfusion injury of the liver. Thus, regulation of hepatic tissue cyclic nucleotides is an important alternative for prevention of hepatic damage in liver preservation and surgery.

Background: The suppressed production of nitric oxide (NO), associated with endothelial dysfunction, is thought to be a cause of ischemia and reperfusion injury of the liver. But findings of the salutary effects of NO enhancement on such injury have been conflicting. In this study, we tested our hypothesis that NO enhancement would attenuate ischemic liver injury. For this purpose, an NO precursor, L-arginine, and a novel NO donor, FK409, were applied to a 2-hour total hepatic vascular exclusion model in dogs. Study Design: L-arginine was administered IV at a dose of 100 mg/kg twice (n = 5), while 300 mg/kg twice of FK409 was infused continuously into the portal vein (n = 5). The drugs were given to the animals for 30 and 60 minutes before and after ischemia, respectively. Nontreated animals were used as the control (n = 10). Two-week survival, systemic and hepatic hemodynamics indices, liver function tests, energy metabolism, and histopathology were analyzed. Results: Both treatments comparably augmented hepatic tissue blood flow, decreased liver enzyme release, and increased high-energy phosphate restoration during the reperfusion period, all of which contributed to rescuing all of the treated animals from the 2-hour total hepatic ischemia. In contrast, ischemia caused 70% mortality in the control group. Histologically, structural abnormality and neutrophil infiltration were markedly attenuated by the treatments. Systemic hypotension was observed in the animals treated with FK409, however. Conclusions: Our data demonstrate that NO enhancement alleviates the liver injury caused by ischemia and reperfusion. The supplementation of L-arginine, rather than FK409, is considered more applicable to clinical use because of the absence of systemic adverse effects.

Background: Enhanced production of endothelin-1 (ET-1), vasoconstrictive 21 amino acids produced by endothelial cells during ischemia and after reperfusion of the liver, is known to cause sinusoidal constriction and microcirculatory disturbances, which lead to severe tissue damage. Using a 2-hour hepatic vascular exclusion model in dogs, we tested our hypothesis that neutralization of ET-1 by monoclonal anti-ET-1 and anti-ET-2 antibody (AwETN40) abates vascular dysfunction and ameliorates ischemia/reperfusion injury of the liver. Study Design: After skeletonization, the liver was made totally ischemic by cross-clamping the portal vein, the hepatic artery, and the vena cava (above and below the liver). Veno-venous bypass was used to decompress splanchnic and inferior systemic congestion. AwETN40, 5 mg/kg, was administered intravenously 10 minutes before ischemia (treatment group, n=5). Nontreated animals were used as controls (control group, n=10). Animal survival, hepatic tissue blood flow, liver function tests, total bile acid, high-energy phosphate, ET-1 levels, and liver histopathology were studied. Results: Treatment with AwETN40 improved 2-week animal survival from 30% to 100%. Hepatic tissue blood flow after reperfusion was significantly higher in the treatment group. The treatment significantly attenuated liver enzyme release, total bile acid, and changes in adenine nucleotides. Immunoreactive ET-1 levels in the hepatic venous blood of the control group showed a significant increase and remained high for up to 24 hours after reperfusion. Histopathologic alterations were significantly lessened in the treatment group. Conclusions: These results indicate that ET-1 is involved in ischemia/reperfusion injury of the liver, which can be ameliorated by the monoclonal anti-ET-1 and anti-ET-2 antibody AwETN40.

BACKGROUND The influence of administration of a nucleoside-nucleotide mixture on hepatic energy metabolism was investigated in 70% hepatectomized rabbits from 48 to 72 hours after hepatectomy. METHODS From 48 to 72 hours after hepatectomy, animals underwent continuous i.v. infusion of 2 mL/kg body weight/h of 9 g/L NaCl (group S), 5.99 mmol/L nucleoside-nucleotide mixture (group N1) or 11.98 mmol/L nucleoside-nucleotide mixture (group N2). RESULTS At 72 hours, there was no significant difference in the hepatic adenylate energy charge among groups (S, 0.84 +/- 0.01; N1, 0.82 +/- 0.02; N2, 0.85 +/- 0.01). The hepatic mitochondrial phosphorylation rate was 66.9 +/- 2.5, 76.3 +/- 11.1, and 108.4 +/- 14.1 nmol ATP/mg mitochondrial protein/min in groups S, N1, and N2, respectively. The value of group N2 was significantly higher than the value of group S (p < .01). In addition, DNA concentration of the remnant liver was 2.27 +/- 0.07, 2.56 +/- 0.17, and 3.19 +/- 0.42 mg/g wet liver in groups S, N1, and N2, respectively, showing a significant increase in group N2 compared with group S (p < .05). CONCLUSION A continuous i.v. infusion of a nucleoside-nucleotide mixture to 70% hepatectomized rabbits from 48 to 72 hours after hepatectomy prolonged an enhancement of the hepatic mitochondrial phosphorylation rate and elevated DNA content of the remnant liver.

Background The immunosuppressive effect and other properties of a novel immunosuppressant, FTY720, have been studied mostly in the experimental transplantation of various extrahepatic organs. In this experiment, we evaluated the antirejection potency and adverse effects of this agent on liver grafts using a canine liver transplantation model. Methods. Forty-eight orthotopic liver transplantations were performed by the standard technique under a veno-venous bypass. Liver recipients were divided into two studies: a single-dose study with FTY720 at various doses and a combined dose study with conventional immunosuppressants (cyclosporine or tacrolimus) alone and combined with FTY720. Survival, biochemical and hematological tests, blood levels of immunosuppressants, and postmortem histology were determined. Results. The median survival of untreated control animals was 9 days, whereas treatment with FTY720 at a dose of 0.1 mg/kg/day prolonged graft survival to 49.5 days. FTY720 at 1 mg/kg/day showed a slight but insignificant prolongation to 16 days, but when the dose was increased to 5 mg/kg/day, the graft was rejected at 10 days. The combination of FTY720, 0.1 mg/kg/day, with a subtherapeutic dose of cyclosporine, 5 mg/kg/ day, prolonged median animal survival from 40 days with cyclosporine alone to 74 days. A combination of FTY720 (0.1 mg/kg/day) with tacrolimus (0.5 mg/kg/ day) compromised animal survival, reducing survival from 83.5 days with tacrolimus alone to 30.5 days due to infectious complication and emaciation by overimmunosuppression. No evident drug-induced side effects were observed. Conclusions. FTY720 has a potent immunosuppressive effect when used alone at 0.1 mg/kg/day in canine liver transplantation. FTY720 is a promising candidate for future clinical application in orthotopic liver transplantation.