The importance of iron, calcium and free radicals in reperfusion injury: an overview of studies in ischaemic rabbit kidneys

Mechanisms of haemolysis-induced kidney injury

Intravascular haemolysis is a fundamental feature of chronic hereditary and acquired haemolytic anaemias, including those associated with haemoglobinopathies, complement disorders and infectious diseases such as malaria. Destabilization of red blood cells (RBCs) within the vasculature results in systemic inflammation, vasomotor dysfunction, thrombophilia and proliferative vasculopathy. The haemoprotein scavengers haptoglobin and haemopexin act to limit circulating levels of free haemoglobin, haem and iron - potentially toxic species that are released from injured RBCs. However, these adaptive defence systems can fail owing to ongoing intravascular disintegration of RBCs. Induction of the haem-degrading enzyme haem oxygenase 1 (HO1) - and potentially HO2 - represents a response to, and endogenous defence against, large amounts of cellular haem; however, this system can also become saturated. A frequent adverse consequence of massive and/or chronic haemolysis is kidney injury, which contributes to the morbidity and mortality of chronic haemolytic diseases. Intravascular destruction of RBCs and the resulting accumulation of haemoproteins can induce kidney injury via a number of mechanisms, including oxidative stress and cytotoxicity pathways, through the formation of intratubular casts and through direct as well as indirect proinflammatory effects, the latter via the activation of neutrophils and monocytes. Understanding of the detailed pathophysiology of haemolysis-induced kidney injury offers opportunities for the design and implementation of new therapeutic strategies to counteract the unfavourable and potentially fatal effects of haemolysis on the kidney.

The effects of oxytocin on penile tissues in experimental priapism model in rats

PURPOSE

This study aimed to demonstrate the effects of oxytocin on penile tissues in ischemia-reperfusion injury developed after priapism.

METHODS

Forty Wistar Albino strain male rats were divided into four groups. The control group (n = 10) was not intervened. In Group 2, a rat model of priapism was constructed and maintained for 1 h. In Group 3, reperfusion was ensured for 30 min following priapism. Rats in Group 4 rats were given oxytocin 30 min before the induction of reperfusion following priapism. All rats were penectomized, and adequate amounts of blood sample were drawn. Inflammation, vasocongestion, desquamation, and edema in penile tissue were scored between 0 and 3 points (0: normal, 1: mild, 2: moderate, 3: severe) to evaluate the severity of tissue damage. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the levels of malondialdehyde (MDA), and nitric oxide (NO) in blood samples were determined spectrophotometrically.

RESULTS

In histopathological examination, statistically significant positive changes were detected in vasocongestion, inflammation, desquamation, and edema scores in Group 4 than in Group 2 and Group 3 (p < 0.001). Biochemical test results revealed that NO levels were significantly lower in Group 4 than in Group 3 (p < 0.001). Serum GSH-Px activities in Group 4 significantly increased when compared with the other groups 2 and 3 (p = 0.002, p = 0.001, respectively). There was no statistical difference among the groups regarding SOD activities and MDA levels (p > 0.05).

CONCLUSIONS

Oxytocin protected against priapism-induced ischemia-reperfusion injury developed in cavernosal tissue as observed based on histopathological and biochemical evidence. Although this is an experimental study, oxytocin can be thought as an alternative drug in the treatment of priapism.

Protective Effects of Curcumin Against Ischemia-Reperfusion Injury in the Nervous System

Ischemia-reperfusion injury (I/R injury) is a common feature of ischemic stroke which occurs when blood supply is restored after a period of ischemia. Although stroke is an important cause of death in the world, effective therapeutic strategies aiming at improving neurological outcomes in this disease are lacking. Various studies have suggested the involvement of different mechanisms in the pathogenesis of I/R injury in the nervous system. These mechanisms include oxidative stress, platelet adhesion and aggregation, leukocyte infiltration, complement activation, blood-brain barrier (BBB) disruption, and mitochondria-mediated mechanisms. Curcumin, an active ingredient of turmeric, can affect all these pathways and exert neuroprotective activity culminating in the amelioration of I/R injury in the nervous system. In this review, we discuss the protective effects of curcumin against I/R injury in the nervous system and highlight the studies that have linked biological functions of curcumin and I/R injury improvement.

Targeting Iron Homeostasis in Acute Kidney Injury

Iron is an essential metal involved in several major cellular processes required to maintain life. Because of iron's ability to cause oxidative damage, its transport, metabolism, and storage is strictly controlled in the body, especially in the small intestine, liver, and kidney. Iron plays a major role in acute kidney injury and has been a target for therapeutic intervention. However, the therapies that have been effective in animal models of acute kidney injury have not been successful in human beings. Targeting iron trafficking via ferritin, ferroportin, or hepcidin may offer new insights. This review focuses on the biology of iron, particularly in the kidney, and its implications in acute kidney injury.

Ischemia-reperfusion damage

Ischemia-reperfusion damage is a complex pathological process that begins with tissue anoxia and continues with the production of free oxygen radicals, expanding with the inflammatory response. The literature suggests the importance of antioxidant and anti-inflammatory treatment to treat ischemia-reperfusion-related tissue damage.

Mineralocorticoid receptor blockade reduced oxidative stress in renal transplant recipients: a double-blind, randomized pilot study

BACKGROUND

Previous experimental studies from our laboratory have demonstrated that aldosterone plays a central role in renal ischemic processes. This study was designed to evaluate the effect of mineralocorticoid receptor blockade in renal transplant recipients from living donors.

METHODS

20 adult kidney transplant recipients from living donors were included in a double-blind, randomized, placebo-controlled clinical pilot study that compared spironolactone and placebo. Placebo or spironolactone (25 mg) was administered 1 day before and 3 days posttransplantation. Renal function and urinary kidney injury molecule-1, interleukin-18, and heat shock protein 72 as well as urinary hydrogen peroxide (H2O2) levels were quantified.

RESULTS

No significant differences were seen between the groups studied regarding age, gender, indication for kidney transplantation, residual renal function, renal replacement therapy, or warm and cold ischemia periods. In contrast, spironolactone administration significantly reduced the oxidative stress assessed by the urinary H2O2 excretion, in spite of no differences in renal function or reduction in tubular injury biomarkers.

CONCLUSIONS

The findings of this exploratory study strongly suggest that aldosterone promotes oxidative stress and that the administration of spironolactone reduces the production of urinary H2O2 as a result of lesser formation of surrogate reactive oxygen species secondary to the ischemia-reperfusion phenomenon.

Iron chelating agents with clinical potential

Iron is a critically important metal for a wide variety of cellular events. The element holds this central position by virtue of its facile redox chemistry and the high affinity of both redox states (iron II and iron III) for oxygen. These same properties also render iron toxic when levels exceed the normal binding capacity of the cell. As a result of this potential toxicity, selective iron chelators are finding an important role in the treatment of iron overload associated with many forms of thalassaemia. In addition, they appear to have potential in treating situations where a local increase in iron concentration causes an unfavourable pathology, for instance, in reperfused tissue (heart disease and stroke) and in Parkinsonian brain. There is also evidence that iron chelators may minimise the toxicity of paraquat and the side effects of bleomycin and doxorubicin.

Non-haem iron enzymes can also be inhibited by iron chelators and consequently such enzymes as ribonucleotide reductase and lipoxygenase can be selectively inhibited. Such inhibitory action is being investigated for the treatment of malaria, neoplastic disease, psoriasis and asthma.

Recent developments in these areas are discussed in the present overview.

Measurement of selected ions related to oxidative stress and energy metabolism in Saudi autistic children

OBJECTIVES

Autism is a developmental disorder characterized by social and emotional deficits, language impairments and stereotyped behaviors that manifest in early postnatal life. This study aims to clarify the role of selected ions related to energy metabolism as a consequence of oxidative stress in the deterioration accompanied autism.

MATERIALS AND METHODS

Malonaldehyde as measure of lipid peroxidation, Na(+)/K(+) ion pump (ATPase), together with the concentrations of Na(+), K(+), Mg(2+), Ca(2+) and Pb(2+) were determined in plasma of 30 Saudi autistic patients and compared to 30 age-matching control samples.

RESULTS

The obtained data recorded that Saudi autistic patients have a remarkable higher activities of Na(+)/K(+) ATPase and high levels of lipid peroxidation compared to control. In addition, they have significantly elevated levels of K(+) and Pb(2+) while Ca(2+) recorded a significantly lower level compared to age-matching control subjects. On the other hand both Mg(2+) and Na(+) were non-significantly changed in autistic patients.

CONCLUSION

Alteration of the selected measured ions confirms that oxidative stress and defective mitochondrial energy production could represent the primary causative factor in the pathogenesis of autism.

Disruption of iron homeostasis and lung disease

As a result of a direct exchange with the external environment, the lungs are exposed to both iron and agents with a capacity to disrupt the homeostasis of this metal (e.g. particles). An increased availability of catalytically reactive iron can result from these exposures and, by generating an oxidative stress, this metal can contribute to tissue injury. By importing this Fe(3+) into cells for storage in a chemically less reactive form, the lower respiratory tract demonstrates an ability to mitigate both the oxidative stress presented by iron and its potential for tissue injury. This means that detoxification is accomplished by chemical reduction to Fe(2+) (e.g. by duodenal cytochrome b and other ferrireductases), iron import (e.g. by divalent metal transporter 1 and other transporters), and storage in ferritin. The metal can subsequently be exported from the cell (e.g. by ferroportin 1) in a less reactive state relative to that initially imported. Iron is then transported out of the lung via the mucociliary pathway or blood and lymphatic pathways to the reticuloendothelial system for long term storage. This coordinated handling of iron in the lung appears to be disrupted in several acute diseases on the lung including infections, acute respiratory distress syndrome, transfusion-related acute lung injury, and ischemia-reperfusion. Exposures to bleomycin, dusts and fibers, and paraquat similarly alter iron homeostasis in the lung to affect an oxidative stress. Finally, iron homeostasis is disrupted in numerous chronic lung diseases including pulmonary alveolar proteinosis, transplantation, cigarette smoking, and cystic fibrosis.

Delayed graft function in kidney transplantation

Delayed graft function is a form of acute renal failure resulting in post-transplantation oliguria, increased allograft immunogenicity and risk of acute rejection episodes, and decreased long-term survival. Factors related to the donor and prerenal, renal, or postrenal transplant factors related to the recipient can contribute to this condition. From experimental studies, we have learnt that both ischaemia and reinstitution of blood flow in ischaemically damaged kidneys after hypothermic preservation activate a complex sequence of events that sustain renal injury and play a pivotal part in the development of delayed graft function. Elucidation of the pathophysiology of renal ischaemia and reperfusion injury has contributed to the development of strategies to decrease the rate of delayed graft function, focusing on donor management, organ procurement and preservation techniques, recipient fluid management, and pharmacological agents (vasodilators, antioxidants, anti-inflammatory agents). Several new drugs show promise in animal studies in preventing or ameliorating ischaemia-reperfusion injury and possibly delayed graft function, but definitive clinical trials are lacking. The goal of monotherapy for the prevention or treatment of is perhaps unattainable, and multidrug approaches or single drug targeting multiple signals will be the next step to reduce post-transplantation injury and delayed graft function.

Reduction of circulating redox-active iron by apotransferrin protects against renal ischemia-reperfusion injury

BACKGROUND

Warm ischemia-reperfusion (I/R) injury plays an important role in posttransplant organ failure. In particular, organs from marginal donors suffer I/R injury. Although iron has been implicated in the pathophysiology of renal I/R injury, the mechanism of iron-mediated injury remains to be established. The authors therefore investigated the role of circulating redox-active iron in an experimental model for renal I/R injury.

METHODS

Male Swiss mice were subjected to unilateral renal ischemia for 45 min, followed by contralateral nephrectomy and reperfusion. To investigate the role of circulating iron, mice were treated with apotransferrin, an endogenous iron-binding protein, or iron-saturated apotransferrin (holotransferrin).

RESULTS

Renal ischemia induced a significant increase in circulating redox-active iron levels during reperfusion. Apotransferrin, in contrast to holotransferrin, reduced the amount of circulating redox-active iron and abrogated renal superoxide formation. Apotransferrin treatment did not affect I/R-induced renal apoptosis, whereas holotransferrin aggravated apoptotic cell death. Apotransferrin, in contrast to holotransferrin, inhibited the influx of neutrophils. Both apo- and holotransferrin reduced I/R-induced complement deposition, indicating that the effects of transferrin are differentially mediated by its iron and protein moiety. Finally, apotransferrin, in contrast to holotransferrin, dose-dependently inhibited the loss of renal function induced by ischemia.

CONCLUSIONS

Redox-active iron is released into the circulation in the course of renal I/R. Reducing the amount of circulating redox-active iron by treatment with apotransferrin protects against renal I/R injury, inhibiting oxidative stress, inflammation, and loss of function. Apotransferrin could be used in the treatment of acute renal failure, as seen after transplantation of ischemically damaged organs.

Effect of U-74500A, a 21-aminosteroid on renal ischemia-reperfusion injury in rats

Renal ischemia-reperfusion injury constitutes the most common pathogenic factor for acute renal failure and is the main contributor to renal dysfunction in allograft recipients and revascularization surgeries. Many studies have demonstrated that reactive oxygen species play an important role in ischemic acute renal failure. The aim of the present study was to investigate the effects of the synthetic antioxidant U-74500A, a 21-aminosteroid in a rat model of renal ischemia-reperfusion injury. Renal ischemia-reperfusion was induced by clamping unilateral renal artery for 45 min followed by 24 h of reperfusion. Two doses of U-74500A (4.0 mg/kg, i.v.) were administered 45 min prior to renal artery occlusion and then 15 min prior to reperfusion. Tissue lipid peroxidation was measured as thiobarbituric acid reacting substances (TBARS) in kidney homogenates. Renal function was assessed by estimating serum creatinine, blood urea nitrogen (BUN), creatinine and urea clearance. Renal morphological alterations were assessed by histopathological examination of hematoxylin-eosin stained sections of the kidneys. Ischemia-reperfusion produced elevated levels of TBARS and deteriorated the renal function as assessed by increased serum creatinine, BUN and decreased creatinine and urea clearance as compared to sham operated rats. The ischemic kidneys of rats showed severe hyaline casts, epithelial swelling, proteinaceous debris, tubular necrosis, medullary congestion and hemorrhage. U-74500A markedly attenuated elevated levels of TBARS as well as morphological changes, but did not improve renal dysfunction in rats subjected to renal ischemia-reperfusion. These results clearly demonstrate the in vivo antioxidant effect of U-74500A, a 21-aminosteroid in attenuating renal ischemia-reperfusion injury.

Catalase prevents elevation of [Ca(2+)](i) induced by alcohol in cultured canine cerebral vascular smooth muscle cells: Possible relationship to alcohol-induced stroke and brain pathology

Several studies have suggested that alcohol-induced brain injury is associated with generation of reactive oxygen species (ROS). The recent findings, that antioxidants (Vitamin E and pyrrolidine dithiocarbamate (PDTC)) prevent intracellular Ca(2+) ([Ca(2+)](i)) overload in cerebral vascular smooth muscle cells, induced by alcohol, demonstrate indirectly that ROS formation is related to cerebral vascular injury. The present experiments were designed to test the hypothesis that catalase, an hydrogen peroxide (H(2)O(2)) scavenging enzyme, can prevent or ameliorate alcohol-induced elevation of [Ca(2+)](i). Preincubation of cultured canine cerebral vascular smooth muscle cells with catalase (20-1000 units/ml) didn't produce any apparent changes from controls in resting levels of [Ca(2+)](i) after 1-3 days. Exposure of the cerebral vascular cells to culture media containing 10-100mM ethanol resulted in significant rises in [Ca(2+)](i) (p<0.01). Although exposure of these cells to a low concentration of catalase (20 units/ml) failed to prevent the increased level of [Ca(2+)](i) induced by ethanol, concomitant addition of higher concentrations of catalase (100-1000 units/ml) and ethanol (10-100mM) inhibited or ameliorated the rises of [Ca(2+)](i) induced by ethanol either at 24h or at 3 days, in a concentration-dependent manner. Catalase, in the range of 100-200 units/ml, inhibited approximately 50% of the [Ca(2+)](i) increases caused by ethanol in the first 24h. Catalase at a concentration of 1000 units/ml inhibited completely excessive [Ca(2+)](i) accumulation. The present results when viewed in light of other recently published data suggest that H(2)O(2) generation may be one of the earliest events triggered by alcohol in alcohol-induced brain-vascular damage, neurobehavioral actions and stroke.

Benidipine inhibits apoptosis during ischaemic acute renal failure in rats

We have investigated the effects of benidipine (hydrochloride), a calcium antagonist, against ischaemic acute renal failure in rats. Using histological examination, we studied whether the inhibition of apoptosis was associated with the protective effects of benidipine on the ischaemic renal injury. Acute renal failure was induced by the unilateral clamping of the left renal artery for 60 min, followed by reperfusion and contralateral nephrectomy. Drugs were given intravenously 5 min before the unilateral clamping. Prophylactic administrations of benidipine (10 microg kg(-1), i.v.) significantly ameliorated the development of renal failure as estimated by the measurements of serum creatinine and blood urea nitrogen 24 h after the reperfusion. Amlodipine (besilate, 100 and 300 microg kg(-1), i.v.) tended to attenuate renal dysfunction. Lisinopril (300 and 1000 microg kg(-1), i.v.), an angiotensin converting enzyme inhibitor, was ineffective in this acute renal failure model. Histological examination using the terminal transferase-mediated dUTP-biotin nick end-labelling (TUNEL) method to detect apoptotic cells revealed that the TUNEL-positive tubular epithelium was prominent in the renal cortex 24 h after the reperfusion. The TUNEL-positive cells were significantly reduced by pretreatment with benidipine. The results demonstrate that benidipine can ameliorate the ischaemic acute renal failure in rats and suggest that the renoprotective effect of benidipine was at least partly attributable to the reduction of apoptosis in tubular epithelial cells.

The role of allopurinol and deferoxamine in preventing pressure ulcers in pigs

Ischemia and reperfusion may be important in the pathogenesis of pressure ulcers. On the basis of this hypothesis, the effects of intermittent pressure and the anti-free radical agents allopurinol and deferoxamine were studied in a pig model in which a pressure of 150 mmHg was applied intermittently to the scapulae. Cutaneous blood flow, transcutaneous oxygen tension, skin and muscle damage, and muscle levels of adenosine triphosphate were quantified. A control group of pigs (n = 6) was untreated, the allopurinol group (n = 6) received oral allopurinol beginning 2 days before the experiment, and the deferoxamine group (n = 6) received an intramuscular injection of deferoxamine 2 hours before the experiment. Pressure (150 mmHg) was applied to the scapulae for 210 minutes, and it was relieved for 30 minutes. This 4-hour cycle was repeated continuously for 48 hours, and it resulted in pressure injuries in all animals. Allopurinol and deferoxamine improved cutaneous blood flow and tissue oxygenation, but only deferoxamine could significantly reduce cutaneous and skeletal muscle necrosis (p < 0.001). This study suggests a future role for anti-free radical agents in the reduction of pressure-induced injury.

Role of mitochondria and calcium ions in tributyltin-induced gene regulatory pathways

Tributyltin (TBT) salts are potent skin irritants both in humans and rodents. Data in the literature indicate mitochondria as target of TBT effects. Here, we investigate the early intracellular molecular events that follow TBT treatment and the relevance of calcium ions and mitochondria in gene-regulatory signaling pathways. Confluent HEL30 cells were treated with increasing doses of TBT (0-5 microM). At different times thereafter, the level of intracellular Ca2+, the cellular oxidative activity, nuclear factor-kappaB (NF-kappaB) activation, and IL-1alpha production were measured. TBT induced a dose-related increase of intracellular Ca2+ that reached the plateau 4 min following treatment. The increase of intracellular Ca2+ was followed by an increase in cellular oxidative activity as measured by DCFH oxidation (15 min) that preceded NF-kappaB activation (30 min) and IL-1alpha production (4 hr). All these events can be almost completely abrogated by BAPTA, an intracellular Ca2+ chelator. Furthermore, the modulation of cellular oxidative activity induced by TBT observed with rotenone, an inhibitor of the electron entry from complex I to ubiquinone, or after prolonged treatment with ethidium bromide, an inhibitor of mitochondrial DNA and RNA synthesis, indicates mitochondria as an important intracellular source of reactive oxygen species. These findings indicate the rise in intracellular Ca2+ as the starting event and indicate the role of mitochondria as the source of second messenger molecules essential for TBT-induced NF-kappaB activation and IL-1alpha production.

Renal ischaemia--reperfusion injury

Ischaemia-reperfusion injury is a complex interrelated sequence of events that classically involves the vascular endothelium and activated leucocytes. During the ischaemic phase the endothelium is primed both to produce free radicals and to secrete chemoattractants. The resultant neutrophil sequestration serves to amplify the injury, but damage is not confined to the postischaemic area and more generalized effects typically follow. The situation in the kidney is complex for, while ischaemia primes the tissue for reperfusion damage, it also causes early and irreversible tubular injury. Furthermore, it appears that relatively less importance should be attached to the involvement of neutrophils than at other sites, and relatively more to a local postischaemic imbalance in the levels of nitric oxide and endothelin. Despite a greater understanding of the pathogenesis of ischaemia-reperfusion injury, effective treatment remains elusive and research is hampered by apparent species and organ-specific differences.

Delayed graft function in renal transplantation: etiology, management and long-term significance

PURPOSE

In cadaveric renal transplantation a period of delayed graft function postoperatively is not uncommon and often associated with a poor outcome. We reviewed the biology of reperfusion injury and delayed graft function in renal transplantation, as well as its prevention, management and long-term effects.

MATERIALS AND METHODS

The medical literature covering acute tubular necrosis, delayed graft function in renal transplantation and immunology of ischemia reperfusion injury was reviewed.

RESULTS

Delayed graft function is clearly associated with poor allograft survival, and is caused by an interaction of ischemic and immunological factors. Technical and pharmacological maneuvers can improve early function rates. The response to ischemic injury is complex, and may increase graft immunogenicity and promote the chronic proliferative changes seen in chronic allograft nephropathy.

CONCLUSIONS

Improvement in early renal function should be a primary goal in renal transplantation to enhance early and long-term results. Basic research into the injury response may yield insights into renal pathophysiology.

A digitized fluorescence imaging study of intracellular free calcium, mitochondrial integrity and cytotoxicity in rat renal cells exposed to ionomycin, a calcium ionophore

The objective of this study was to explore the role of extracellular Ca2+ and mitochondrial integrity in ionomycin-induced cytotoxicity in primary cultures of rat kidney cortical epithelial cells using digitized fluorescence imaging (DFI), which is a powerful tool for continuously observing the dynamic intracellular biochemistry of single living cells. Using DFI, intracellular free calcium ion concentration ([Ca2+]i), mitochondrial membrane potential and loss of cell viability in individual rat renal cortical epithelial cells were examined temporally by fura-2, rhodamine 123 (Rh-123) and propidium iodide (PI), respectively. Images were taken within 10 min after exposure to 5 and 10 microM ionomycin. These three parameters, [Ca2+]i, mitochondrial membrane potential and cell viability, were also measured in populations of cells by a multiwell fluorescence scanner with fluo-3, Rh-123 and PI, respectively. Cytotoxicity was also assessed by two colorimetric cytotoxicity tests (LDH leakage and mitochondrial MTT reduction). Using DFI, the fluorescence scanner and the colorimetric cytotoxicity tests, we found that exposure of primary cultures of rat kidney cortical epithelial cells to high concentrations of ionomycin (5 and 10 microM) caused a rapid and sustained rise in [Ca2+]i, which preceded dissipation of the mitochondrial membrane potential and loss of cell viability and that chelation of extracellular Ca2+ with EGTA attenuated these responses. We demonstrated the value of using DFI to continuously observe the dynamic intracellular biochemistry of single living cells by establishing a sequence of elevated [Ca2+]i, dissipation of mitochondrial membrane potential and cytotoxicity. We conclude that a combination of the influx of extracellular Ca2+ and loss of mitochondrial integrity may be responsible for the cytotoxicity observed in individual renal cells and populations of renal cells after treatment with ionomycin.

Ischemia and reperfusion: effect of fructose-1,6-bisphosphate

Several lines of evidence indicating a close relationship among ischemia, concentration of high-energy metabolites and onset of the "oxygen paradox" in reperfused tissues have been published. In this framework, we have recently studied the effects of exogenous fructose-1,6-bisphosphate on energy metabolism and on oxygen free radical damages of isolated rat heart subjected to anoxia and reoxygenation. In comparison with control groups, hearts perfused in the presence of 5 mM fructose-1,6-bisphosphate throughout the different perfusion conditions showed higher concentrations of energy metabolites at the end of anoxia, most of which were normalized after reperfusion. Furthermore, in comparison with control hearts, a reduction of tissue malondialdehyde and of lactate dehydrogenase release in the perfusate was observed in fructose-1,6-bisphosphate-perfused hearts. In this article we review most of the available data concerning the ability of fructose-1,6-bisphosphate to protect from ischemia and reperfusion damage outlining those recent findings which contributed both to clarify the pharmacological profile of the drug and to give an insight in its probable mechanism of action.