Uptake and disposition of putrescine, spermidine, and spermine by rabbit lungs

The pulmonary uptake and accumulation of the three polyamines in intact, ventilated, and perfused rabbit lungs was investigated. Lungs were perfused using Krebs-Ringer bicarbonate buffer with albumin in which putrescine, spermidine, or spermine were included at an initial concentration of 10(-3), 10(-2), 10(-1), 5, 10, or 20 mM. At a 5 mM concentration of spermidine and spermine, the uptake by isolated lungs reached a steady state equilibrium in 20-30 min of perfusion. This did not occur for putrescine, which showed linear uptake throughout the entire period of the 60-min perfusion. The lung uptake of putrescine for all perfusate concentrations was greater than that of spermidine or spermine, but all three showed concentration-dependent linear uptake. In the presence of harmaline (1 mM) and ouabain (1 mM), isolated perfused rabbit lungs showed a decrease in uptake of putrescine although no effect was seen for spermidine and spermine. Perfusate containing decreased sodium showed no effect on putrescine uptake by isolated rabbit lungs, but there was a significant increase in the uptake of spermidine and spermine. Significant uptake of all three polyamines was also observed when incubated separately with rabbit lung slices for 60 min. HPLC analysis of lung, the perfusate samples, lung slices, and the incubation medium after a 60-min incubation did not indicate the presence of metabolites of these polyamines. Likewise, the analysis of the lung homogenate incubated with polyamines did not show any metabolites confirming the absence of detectable pulmonary metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)     

Structural requirements of compounds to inhibit pulmonary diamine accumulation

The diamine, putrescine, is accumulated into slices of rat lung by a temperature and energy dependent process similar to that responsible for the uptake of cadaverine, the polyamines spermidine and spermine, and the herbicide paraquat. Structure-activity studies using monoamines and diaminoalkanes, amino acids and guanidino compounds, have shown that in order to inhibit the pulmonary accumulation of putrescine, chemicals should possess at least one but preferably two nitrogen-containing cationic groups. In the series of alpha, w-diaminoalkanes studied, the inhibitory potential increased with increasing chain length, reaching a plateau at 1,7-diaminoheptane. These observations together with the fact that putrescine is a good substrate for the uptake system (Km 15 microM, Vmax 704 nmoles/g wet wt/hr) suggest that effective inhibitors require at least four methylene groups between their cationic centres and that diamines with more methylene groups may fold to give this separation. With both the monoamines and the alpha, w-diaminoalkanes, changes in the free energies of interaction suggest that the observed increases in inhibitory potential with increasing chain length are due to increased hydrophobic bonding, which is a consequence of the addition of methylene groups to the alkyl chain. Furthermore, the ability of compounds to inhibit putrescine uptake appears to be related to their propensity to bind with the appropriate site for putrescine. Steric hindrance of this ionic interaction by the quaternisation of the cationic centres of the inhibitors with methyl groups, results in a total loss of measurable inhibitory activity. Also, the introduction of anionic carboxyl groups into inhibitors result in a loss of inhibitory potential, probably due to ionic repulsion. The antileukaemic drug, methylglyoxal-bis-guanylhydrazone (MeGAG), and its congeners, were some of the most potent inhibitors of putrescine uptake studied. Our findings suggest similarities between the uptake system for putrescine into the lung with other uptake systems described for MeGAG and certain polyamines.     

Polyamines allosterically modulate [3H]nitrendipine binding to the voltage-sensitive calcium channel in rat brain

The effects of polyamines on radioligand binding to the slow voltage-dependent Ca²⁺ channel were studied using membranes from the rat cerebral cortex. [³H]Diltiazem binding was inhibited by arcaine (IC₅₀ = 55 μM) and, in decreasing order of potency, by agmatine, spermidine, spermine and putrescine. Under control conditions, only spermidine and spermine allosterically inhibited [³H]nitrendipine binding while arcaine, agmatine and putrescine were inactive. Nevertheless, putrescine antagonized the effect of spermine as well as the allosteric effects of diltiazem and verapamil on the binding of [³H]nitrendipine, in a manner analogous to that shown previously for Ca²⁺. Thus, polyamines may function as endogenous modulators of the voltage-dependent Ca²⁺ channel.     

Molecular basis for cellular effects of naturally occurring polyamines.

The naturally occurring polyamines, putrescine, spermidine and spermine, and the analogue cadaverine, induce a dose-dependent histamine release from rat peritoneal mast cells. Spermine was the most active among these polycationic metabolites, followed by spermidine and putrescine. The histamine release was inhibited by a 2 h pretreatment of the cells with pertussis toxin (100 ng/ml), demonstrating the involvement of a pertussis toxin-sensitive GTP-binding regulatory protein during the exocytotic process. Experiments performed with purified Go/Gi proteins reconstituted into phospholipid vesicles showed a direct stimulation of GTPase activity by the polyamines. This direct stimulation of G proteins and the consequent activation of the coupled effectors may represent a new mechanism of action for natural polyamines controlling receptor-dependent processes.     

Polyamine levels and ornithine decarboxylase activity in blood and erythrocytes in human diseases

Serum and erythrocyte levels of the polyamines spermine, spermidine and putrescine, as well as ornithine decarboxylase in erythrocytes, were studied in patients with different neoplasms (breast, lung and colon cancer) and in those with a nonmalignant proliferative disease (familial polyposis). The blood levels of polyamines and the spermine/putrescine ratio were significantly higher in all tumors and in nonmalignant colon polyposis. In erythrocyte ornithine decarboxylase activity, spermine and spermidine levels, as well as spermidine/putrescine and spermine/putrescine ratios showed a significant decrease after surgery and chemotherapy. Our data suggest that high levels of blood polyamines and erythrocyte ornithine decarboxylase activity are related to cell proliferation and cancer treatment, but that levels of polyamines in serum and erythrocytes are still significantly high after cancer treatment and are similar to those in polyposis disease. Polyamines are related to nuclear activity during differentiation; therefore, the altered turnover of polyamines could be a sign of abnormal nuclear function. Since polyamines stimulate protooncogene expression, their high levels could be considered an important cofactor in malignant cell transformation.     

Inhibition of the bioenergetic functions of isolated rat liver mitochondria by polyamines

The abilities of the naturally occuring polyamines, putrescine, spermidine and spermine, to affect variables related to the bioenergetic functions of isolated rat liver mitochondria were studied. At concentrations comparable to those present intracellularly, the polyamines inhibited state 4 respiration, but they had much less effect on state 3 or uncoupled respiration. The concentrations required to produce 25% inhibition (I₂₅) of state 4 respiration varied according to the polyamine, with putrescine being least effective (I₂₅, 20mM) and spermidine and spermine being more effective and comparable (I₂₅, 7.5 and 7.0mM respectively). This inhibition was antagonized by 15 mM potassium and enhanced by valinomycin and 4 mM magnesium. Inhibition of monoamine oxidase, an enzyme of outer mitochondrial membrane, was also observed to occur. Addition of polyamines to mitochondrial suspensions caused an increase in the optical density and protected against the swelling effects of sublytic concentrations of Triton X-100. By electron microscopy, polyamines were found to cause the outer mitochondrial compartment to collapse bringing the inner and outer membranes into apparent contact with one another. The electrophoretic mobility of mitochondria toward the anode was markedly slowed by polyamines (i.e. 50% by 1.25 mM spermine), indicating surface binding and neutralization of the negative surface charge. In almost all of the above mitochondrial effects, spermine and spermidine were similar in effectiveness and putrescine was less effective. It is suggested that polyamines may be capable of modulating respiration of isolated mitochondria by binding to non-specific anionic sites at the surface of the inner mitochondrial membrane. Neutralization of the net negative surface potential may interfere with cation fluxes across the membrane, particularly those of potassium.     

Acetylated Polyamines in Lungs from Rats with Monocrotaline-Induced Pneumotoxicity

Multiple lines of evidence implicate the polyamines, putrescine,spermidine, and spermine in the lung injury and hypertensivepulmonary vascular disease produced in rats by the pyrrolizidinealkaloid monocrotaline. While increases in lung polyamine contentevoked by monocrotaline can be attributed in part to inductionof the two rate-limiting enzymes in de novo polyamine synthesis,ornithine decarboxylase and S-adenosylmethionine decarboxylase,little attention has been paid to the role that catabolic interconversionprocesses might play in lung polyamine accumulation. Accordingly,the present study evaluated dose (10–60 mg/kg) and time(0–21 days)-dependent effects of monocrotaline on lungcontents of acetylated polyamines and on the activity of spemidine/spermineacetyltransferase (SAT), the enzyme affecting spermidine acetylation.A single subcutaneous injection of monocrotaline produced dose-and time-dependent increases in the lung contents of N¹-acetylspermidine.Neither N¹-acetylspermine nor N¹-acetylputrescine could be detectedin lungs from control rats or from rats treated with monocrotaline.SAT activity also was increased in monocrotaline-treated ratlungs in a dose- and tunedependent manner that was closely relatedto increases in the lung burden of N¹-acetylspermidine. As expected,monocrotaline also caused dose- and time-dependent elevationsin the lung contents of the primary polyamines, putrescine,spermidine, and spermine. Right ventricular hypertrophy, anindex of sustained pulmonary hypertension, did not develop inanimals treated with 10 or 20 mg/kg monocrotaline despite elevationsin the lung contents of putrescine and N¹-acetylspermidine andincreases in the activity of SAT. In contrast,30 and 60 mg/kgmonocrotaline provoked right ventricular hypertrophy accompaniedby elevations in the primary polyaming N¹-acetylspermidine,and SAT activity. These observations indicate that monocrotaline-inducedpneumotoxicity, characterized by development of sustained pulmonaryhypertension, is associated with increased activity of SAT andaccumulation of N¹-acetylspermidine as well as the primary polyamines.This association suggests that polyamine interconversion pathwaysmay be important in development of monocrotaline-induced pneumotoxicity.     

Polyamine synthesis in rat lungs injured with alpha-naphthylthiourea

The diamine, putrescine, and polyamines, spermidine and spermine, are low molecular weight organic cations with documented regulatory roles in cell growth and differentiation. Multiple lines of direct and indirect evidence suggest that these organic cations also may function in stimulus-response coupling processes regulating cellular injury and repair. For example, recent studies in monocrotaline-treated rats, hyperoxic rats, and in cultured pulmonary endothelial cells suggest that polyamines regulate pulmonary endothelial integrity and may thus participate in development and/or regression of acute edematous lung injury. To determine if the polyamines are involved in a well-characterized animal model of acute lung injury, the present experiments assessed the relation between changes in polyamine synthesis and development of edema in lungs from rats treated with alpha-naphthylthiourea (ANTU). ANTU caused dose- and time-dependent increases in the lung activity of the initial and rate-limiting enzyme in polyamine biosynthesis, ornithine decarboxylase (ODC) and in the lung contents of the polyamines putrescine, spermidine, and spermine. ANTU also caused dose- and time-dependent increases in the lung wet-to-dry weight ratio indicative of pulmonary edema formation. Changes in lung polyamine biosyntheic activity after ANTU did not relate temporally to changes in the lung wet-to-dry weight ratio: ODC activity was depressed during the 3-h period immediately following ANTU administration, a period when the wet-to-dry weight ratio was increasing, and markedly elevated at 18 h after ANTU administration when the wet-to-dry weight ratio had returned to control levels. Pretreatment of the animals with alpha-difluoromethylornithine, a highly specific inhibitor of ODC, failed to attenuate ANTU-induced increases in lung wet-to-dry weight ratio. These observations indicate polyamine synthesis is enhanced in rat lungs with ANTU-induced pulmonary edema but, unlike certain other models of lung injury and pulmonary edema, accumulation of polyamines probably is not essential for development of edematous lung injury. It is conceivable that in this animal model polyamines play a role in lung repair processes or some longer-term consequence of lung injury.     

Determination of rat hepatic polyamines by electron-capture gas chromatography

INTRODUCTION: An efficient and reproducible electron-capture gas chromatographic protocol that allows the simultaneous detection and quantification of the polyamines putrescine (1,4-diaminobutane), cadaverine (1,5-diaminopentane), and spermidine (N-[3-aminopropyl]-1,4-diaminobutane) was developed. METHODS: Hepatic tissue from male Sprague-Dawley rats was used for analysis. The polyamines and the internal standard (sertraline) were extracted and derivatized with pentafluorobenzoyl chloride (PFBC) under basic aqueous conditions prior to analysis on a gas chromatograph equipped with a capillary column (narrow-bore fused silica column; 25 mm x 0.32 mm) and an electron-capture detector. RESULTS: PFBC reacts with the amine functions of the polyamines examined here to produce PFB derivatives with high sensitivity on electron-capture detection. The method permitted the quantitative analyses of all three amines in rat hepatic tissue; the concentration of putrescine, but not spermidine, was increased significantly following a 14-day administration of the diamine oxidase (DAO) inhibitor aminoguanidine. Cadaverine was also present at increased concentrations in hepatic homogenates from aminoguanidine-treated rats. DISCUSSION: Extractive derivatization with PFBC followed by gas chromatographic analysis using electron-capture detection results in a rapid and reproducible assay that permits the simultaneous detection and quantification of putrescine, cadaverine, and spermidine in biological tissue.     

Role of polyamines in myocardial ischemia/reperfusion injury and their interactions with nitric oxide

Polyamines (putrescine, spermidine, and spermine) are present in all higher eukaryotic cells and are essential for cell growth, differentiation and apoptosis. Sharing common precursor with polyamines, nitric oxide (NO) is associated with myocardial ischemia/reperfusion injury by the generation of peroxynitrite. Although polyamines have been implicated in tissue ischemia injury, their metabolism and interactions with NO in myocardial ischemia/reperfusion injury have not been fully understood. In our experiment, when Langendorff perfused rat hearts were subjected to 40 min ischemia without reperfusion, both ornithine decarboxylase (ODC) and Spermidine/spermine N(1)-acetyltransferase (SSAT) activities were up-regulated and putrescine accumulated. While after reperfusion, ODC activity decreased and SSAT activity increased, resulting in putrescine accumulation and decreased spermidine and spermine. Meanwhile NO content was increased. In addition, sodium nitroprusside (SNP, a NO donor) decreased ODC activity in cardiac tissue homogenate but increased SSAT activity in a dose-dependent manner. Pre-treatment of isolated heart with N(omega)-nitro-L-arginine methyl ester hydrochloride (L-NAME, an inhibitor of NO synthase) increased ODC activity. Exogenous spermine (1 mM) administration prior to ischemia prevented spermine decrease, reduced cardiac myocyte necrosis and apoptosis, and promoted the recovery of cardiac function after ischemia/reperfusion. These results suggest that acute heart ischemia activates myocardial polyamine stress response characterized by increased ODC and SSAT activities and accumulation of putrescine. Ischemia/reperfusion disturbs polyamine metabolism, and the loss of spermine might be associated with NO increase and thereby influences myocardial cell viability. Exogenous spermine may protect the hearts from myocardial ischemia/reperfusion injury.     

Chemotherapeutic Targeting of Etoposide to Various Tissues on the Basis of Polyamine Level

The effects of etoposide on body weight, organ weights and the concentrations of putrescine, spermidine and spermine in 14 different tissues were examined in rats that had been given the drug for five consecutive days. Etoposide reduces all polyamines, which are associated with tumor cell growth, in the thymus and reduces polyamines of two kinds in the spleen, heart, small intestine, skeletal muscle and lung but it increases putrescine in the prostate and spleen, and spermine in the large intestine.     

Chemotherapeutic targeting of etoposide to various tissues on the basis of polyamine level

The effects of etoposide on body weight, organ weights and the concentrations of putrescine, spermidine and spermine in 14 different tissues were examined in rats that had been given the drug for five consecutive days. Etoposide reduces all polyamines, which are associated with tumor cell growth, in the thymus and reduces polyamines of two kinds in the spleen, heart, small intestine, skeletal muscle and lung but it increases putrescine in the prostate and spleen, and spermine in the large intestine.     

Uptake Mechanism of Trientine by Rat Intestinal Brush-border Membrane Vesicles

The uptake characteristics of trientine by rat intestinal brush-border membrane vesicles were studied. The uptake characteristics of trientine were similar to those of the physiological polyamines with respect to the excessive accumulation in vesicles, the pH dependency, the temperature dependency and the ineffectiveness of K⁺ diffusion potential (inside negative). The initial uptake of trientine was saturable with a K_m value of 1.13 mM, which was larger than that of spermine and spermidine. Furthermore, the uptake rate of trientine was dose-dependently inhibited by spermine and spermidine. Spermine competitively inhibited the uptake of trientine with a K_i value of 18.6 μM, and it was close to the K_m value for spermine (30.4 μM). These data suggested that the uptake of trientine was similar to that of spermine and spermidine in rat small intestinal brush-border membrane vesicles, and these polyamines seem to inhibit the absorption of trientine from the gastrointestinal tract.     

Oxidation of di- and polyamines: in vitro effect of amino aldehydes on the vitality of Leishmania promastigotes

The aminoaldehydes 4-aminobutanal and 5-aminopentanal, derived from the oxidation of the diamines putrescine and cadaverine, and 1-(3-aminopropyl)-4-aminobutanal and aminodialdehyde, derived from the oxidation of the polyamines spermidine and spermine, were produced utilizing a copper amine oxidase (CAO) from Euphorbia characias latex and tested with in vitro cultivation of Leishmania infantum promastigotes. Whereas the aminoaldehydes derived from the oxidation of the diamines were stimulating factors for growth of Leishmania infantum promastigotes, the aldehydes derived from polyamines oxidation had a drastic inhibitory effect on the vitality and growth of these parasites. Thus, a double scenario arises, showing the use of aldehydes from diamines to obtain a large number of organisms of Leishmania infantum promastigotes to use in serological studies, whereas the aldehydes derived from polyamines could be used as a new strategy for therapeutic treatment against these parasites.     

Targeting polyamine metabolism and function in cancer and other hyperproliferative diseases

The polyamines spermidine and spermine and their diamine precursor putrescine are naturally occurring, polycationic alkylamines that are essential for eukaryotic cell growth. The requirement for and the metabolism of polyamines are frequently dysregulated in cancer and other hyperproliferative diseases, thus making polyamine function and metabolism attractive targets for therapeutic intervention. Recent advances in our understanding of polyamine function, metabolic regulation, and differences between normal cells and tumour cells with respect to polyamine biology, have reinforced the interest in this target-rich pathway for drug development.     

Assessment of bleomycin-, tallysomycin-, and polyamine-mediated acute lung toxicity by pulmonary lavage angiotensin-converting enzyme activity

The relative acute pulmonary toxicity of bleomycin (BLM) was compared to that produced by tallysomycins (TLM) A, B, and S₁₀b and with that produced by the polyamines spermidine and putrescine, which are normal end constituents of TLM analogs. Doses which produce equitherapeutic responses in experimental animal tumor systems (BLM, 3.5 mg/kg; TLM A, 0.86 mg/kg; TLM B, 2.1 mg/kg; and TLM S₁₀b, 1.75 mg/kg) produced equitoxic acute responses in pulmonary tissue as assessed by the release of angiotensin-converting enzyme (ACE) into lung lavage fluid. These same doses, however, did not produce any significant alteration in serum ACE activity. Three days after intratracheal administration of either spermidine or putrescine there were only small changes in lavage ACE content suggesting little endothelial cell damage. In contrast, these same doses resulted in epithelial cell metaplasia and pulmonary fibrotic changes by 4 weeks following polyamine administration. In contrast to the report by L. Lapi and S. C. Cohen (1977, Cancer Res.37, 1384–1388) which demonstrated that certain polyamines protected fibroblasts from the toxic effects of the bleomycin component A₅in vitro, neither hirudonine nor spermidine prevented acute BLM- or TLM- mediated pulmonary damage in rats.     

Allyglycine affects acetylation of putrescine and spermidine in mouse brain

Administration of allylglycine to mice (.8 mmole/kg, i.p.) results in a depletion of GABA levels, and it is accompanied by a decrease in SAM-DC activity and spermidine and spermine levels (Pajunen et al., 1979). Here we describe a biphasic effect on the acetylation of putrescine and spermidine in mouse brain homogenate. There appears to be an inverse correlation between the initial decrease in spermidine levels at 2 hours and the increase in the acetylation of spermidine. This is suggestive of a conversion of spermidine, probably through N¹-acetylspermidine to putrescine. The peak of putrescine acetylation observed by us at 4 hours may also reflect a conversion of putrescine, via acetylputrescine to GABA. The interconversion hypothesis is supported by the fact that putrescine levels remain essentially stable in spite of a significant depletion of spermidine and spermine. In addition, there is a decrease in putrescine and spermidine acetylation at 8 hours, which coincides with the increase in ODC activity and the increase towards control levels of GAD activity (Pajunen et al., 1979). Such inverse correlations suggest a mechanism for replenishment of polyamines once GAD activity returns to control levels.     

柱前衍生化-高效液相色谱法测定白念珠菌中多胺的含量

目的建立同时测定白念珠菌中4种多胺（腐胺、尸胺、亚精胺和精胺）的HPLC方法。方法样品经苯甲酰氯衍生化,资生堂C18色谱柱（100mm×3．0mm,3．0μm）分离,以甲醇（A）-0．1％甲酸水（B）为流动相进行梯度洗脱,0～5min,30％-48％B;5—12min,48％B;12～15min,48％～70％B;15～25min,70％b,流速0．6ml／min,检测波长254nm。结果腐胺、尸胺、亚精胺和精胺浓度分别在0．775—77．50μg／ml（r=0．9999）、1．160～116．0μg／ml（r=0、9999）、5．800～580．0μg／ml（r=0．9998）、2．533～192．7μg/ml（r=0．9999）的范围内线性关系良好。4种多胺的加样回收率为94．27％～109．3％,精密度RSD〈4％。结论该含量测定方法灵敏、重现性好,能同时测定白念珠菌中4种多胺的含量。     

Polyamines inhibit both platelet aggregation and glycoprotein IIb/IIIa activation

Platelet aggregation is inhibited by the polyamines putrescine, spermidine, and spermine. To date, the mechanism of action has not been clearly identified. Evidence suggests that polyamines may interact with the fibrinogen receptor (GP IIb/IIIa), interfering with platelet-platelet attachment. The effect of polyamines on human platelet aggregation and GP IIb/IIIa activation was evaluated. For the aggregation experiments, platelets were obtained from heparin- or citrate-collected blood. Our results indicate that the polyamines putrescine, spermidine, and spermine cause a dose-dependent inhibition of ADP- or collagen-mediated platelet aggregation with an order of potency spermine>spermidine>putrescine. In addition, spermine arrests or inhibits thrombin-, epinephrine-, arachidonate-, or ristocetin-induced platelet aggregation. Expression of platelet membrane glycoproteins IIb, IIIa, and IX is not reduced by polyamines. However, spermine inhibits the ADP- or thrombin-induced activation of GP IIb/IIIa. It is concluded that the final step in aggregation, common to all agonists, ie, fibrinogen binding to GP IIb/IIIa, is inhibited by spermine through inhibition of the agonist-induced activation of GP IIb/IIIa that precedes fibrinogen-ligand binding.     

Association between remote organ injury and tissue polyamine homeostasis in acute experimental pancreatitis - treatment with a polyamine analogue bismethylspermine

Experimental pancreatitis is associated with activation of polyamine catabolism. The polyamine analog bismethylspermine (Me(2)Spm) can ameliorate pancreatic injury. We investigated the roles of polyamine catabolism in remote organs during pancreatitis and explored the mechanism of polyamine catabolism by administering Me(2)Spm. Acute pancreatitis was induced by an infusion of 2 or 6% taurodeoxycholate before Me(2)Spm administration. Blood, urine and tissues were sampled at 24 and 72 h to assess multi-organ injury and polyamine catabolism. The effect of Me(2)Spm on mortality in experimental pancreatitis was tested separately. Liver putrescine levels were elevated following liver injury. Me(2)Spm increased the activity of spermidine/spermine N(1)-acetyltransferase (SSAT) and depleted the spermidine, spermine or putrescine levels. Lung putrescine levels increased, and SSAT and spermine decreased following lung injury. Me(2)Spm enhanced the activity of SSAT and decreased the spermidine and spermine levels. Renal injury was manifested as an increase in creatinine or a decrease in urine output. Decreases in kidney SSAT, spermidine or spermine and an increase in putrescine were found during pancreatitis. In the 2% taurodeoxycholate model, Me(2)Spm decreased urine output and raised plasma creatinine levels. Me(2)Spm increased SSAT and decreased polyamines. Excessive Me(2)Spm accumulated in the kidney, and greater amounts were found in the 6% taurodeoxycholate model in which this mortality was not reduced by Me(2)Spm. In the 2% taurodeoxycholate model, Me(2)Spm dose-dependently induced mortality at 72 h. Like pancreatic injury, remote organ injury in pancreatitis is associated with increased putrescine levels. However, Me(2)Spm could not ameliorate multi-organ injury. Me(2)Spm administration was associated with significant renal toxicity and induced mortality, suggesting that the current dose is too high and needs to be modified.