Ibuprofen protects rat livers from oxygen-derived free radical-mediated injury after tourniquet shock

Rats subjected to tourniquet shock suffer a severe form of circulatory shock, tissue and organ oxidative stress, and final multiple system organ failure (MSOF) and death of the animals within 24 h of tourniquet release. The oxidative damage observed in hind-limb muscle tissue after reperfusion does not by itself account for the final systemic and lethal MSOF. We have postulated that organ failure has its genesis in a primary perfusion abnormality, e.g. the hind limbs, which is followed by secondary hypoperfusion of other organs, such as the liver, as has been shown to be the case in several septic shock models. It has also been shown that injured or necrotic tissue can activate neutrophils, Küpffer cells, platelets, and both the complement and coagulation cascades. In turn, complement activation also leads to neutrophil and Küpffer cell activation as assessed by their capacity to generate oxyradicals. Herein we have evaluated the potential protective effect of ibuprofen on hepatic oxygen-derived free radical production, as well as its effects on both polymorphonuclear leucocyte (PMN) activation and liver infiltration. The protective effect of ibuprofen on hepatic oxidative injury was assessed by determining total thiol groups (SH), thiobarbituric acid-reactive substances (TBARS), and by the release of aspartic acid (AsT) and alanine (AIT) aminotransferases in control animals, in animals subjected to 5 h of tourniquets, and in animals after 2 h of hind-limb reperfusion. Liver infiltration by PMNs was determined by histology after staining with eosin-hematoxylin, and PMN activation by their capacity to reduce nitro blue tetrazolium (NBT).(ABSTRACT TRUNCATED AT 250 WORDS)

[The injury of heart of rats sustaining delayed fluid resuscitation after burn shock]

Delayed fluid resuscitation of burn shock may lead to many harmful effects. We investigated the injury of heart of burned rats having no fluid resuscitation, immediate and delayed fluid replacement. We used electron spin resonance (ESR) to determine the presence of oxygen free radicals (OFR). We also found significant increase in malondialdehyde (MDA) in delayed resuscitation group. The activity of lactate dehydrogenase isoenzyme (LDH) and creatine phosphokinase isoenzyme (CPK-MB) were increased in the latter group. Immediate fluid replacement can not protect the heart perfectly. Some new measure should be added to the fluid replacement in burn shock.

[Effect of hypothalamic paraventricular beta-endorphin on burn shock in rats]

Dynamic changes of immunoreactive beta-endorphin (ir-beta-EP) in perfusates collected from hypothalamic paraventricular nuclei at different times after burn, and the effects of intrahypothalamic paraventricular microinjection of beta-endorphin or its antiserum on various cardiac indices (MAP, dP/dtmax, Lvsp and HR) and survival time, were observed in anesthetized SD rats after third degree burn of 20% total body surface area. The results showed a significant increase of ir-beta-endorphin contents in the perfusate with the appearance of two peaks. According to the cardiac indices and mean survival time, the condition of the burned animals were improved by injection of anti-beta-endorphin serum, while injection of beta-endorphin did the reverse. The above results suggest that massive accumulation of beta-endorphin in the paraventricular nucleus appears to be one of the important factors detrimental to burn shock.

[The pharmacokinetics of ceftazidime in the burned patients]

Pharmacokinetic studies were carried out following systemic administration of ceftazidime in ten burn patients (TBSA 30%-60% and with full-thickness burn) and six healthy volunteers. Dynamic ceftazidime concentrations in blood, urine and blister fluid were analysed by HPLC. The results showed that the burned patients, especially during their shock phase, some pharmacokinetics parameters differed from that of normal volunteers, in that the volume of distribution (0.45 +/- 0.06 L/kg vs. 0.23 +/- 0.05 L/kg) and non-renal clearance of drug (30.54 +/- 21.97ml.min-1 vs. 11.08 +/- 4.91 ml.min-1) increased, but the elimination of half-life was prolonged. The result indicated that it was not necessary to increase the dosage of ceftazidime in extensive burns in the early period. Burn blister fluid concentrations were higher than MIC. Ranging from 1.004-21.62 micrograms/ml, indicating that systemic ceftazidime could penetrate second-degree burn tissue in the early postburn stage.

Effects of trauma on immune cell function: impairment of intracellular calcium signaling

Immunosuppression following injury influences infectious morbidity and mortality. Impaired T-cell activation conceding to inadequate antigen recognition contributes to this immunosuppression. Successful activation and proliferation of T-cells requires precisely specified levels of intracellular calcium thresholds and peak signals. The purpose of this study was to evaluate intracellular calcium signaling following injury. Hospitalized blunt and penetrating trauma patients in a Level 1 Trauma Center following injury and sepsis were tested for immune cell calcium signaling. Peripheral blood mononuclear cells (PBMC) were isolated and calcium signaling tested with Fura-2 AM. PBMC from trauma patients had significantly depressed values of baseline, peak and sustained levels of intracellular calcium prior to and following phytohemagglutinin stimulation when compared to normal controls. This deficit in intracellular calcium signaling is more severe in septic trauma patients (60% reduction). Suppression of calcium signaling appears to be mediated by at least, in part, circulating serum factors. Prostaglandin E2 seems to have a limited contribution to this effect as it is suppressive only when in direct contact with PBMC. Immune cell activation failure can in part be explained by the inadequacy of calcium signaling; restoration of immunocompetence following trauma will have to be addressed by strategies to restore calcium signaling, a vital step necessary for T-cell proliferation following antigen recognition.

[Mechanisms of the beneficial effect of indomethacin and nimodipine in the treatment of traumatic shock in rats]

Aiming to study the pathogenetic mechanisms of the disturbed function of the central nervous system in traumatic shock we have determined the dynamics of changes of eicosanoids (PGF2 alpha, TxB2, 6-keto-PGF1 alpha, peptidoleukotrienes) in the brain structures (medulla oblongata, hypothalamus) of the experimental animals subjected to bilateral trauma of the hind legs (tourniquet trauma, LD50). Considering that our previous data have shown the importance of eicosanoid mediatory system in the pathogenetic mechanisms of shock, we have studied possible use of prostaglandin synthesis inhibitors (indomethacin) and calcium channel antagonists (nimidipine) in traumatic shock. The authors have concluded that in the pathogenetic mechanism of the disturbed function of the CNS in traumatic shock the important role has peptidoleukotrienes as well as that the combined use of prostaglandin synthesis inhibitors and antagonists of voltage-dependent calcium channel would be useful in the therapy of the injured patients.

[Isoform pattern of inducible HSP 70 in the rat myocardium after heat shock]

The hsp 70 content was measured in the myocardium of a control rat group, in the group of rats 24 hours following a heat shock and in the group of rats 48 hours after a heat shock. In 24 hours after the heat shock, a major inducible hsp 70 with molecular weight of 71 kDa and pI about 5.8 occurred which was utterly absent in myocardial cytosol from control animals. In addition, there was an increase in polypeptide fraction with molecular weight of 73 kDa and pI about 5.6 (HSX73). In 48 hours after the heat shock, first the inducible hsp 70 with molecular weight of 71 kDa and pI about 5.8 disappeared which was found in 24 hours; secondly, HSX73 decreased to the control level and, thirdly, several isoforms pronouncedly accumulated with molecular weight of about 71 kDa and pI ranging from 5.9 to 6.3. Thus, the isoform composition of stress proteins induced by heat shock strongly depends on the time after the stress exposure. Furthermore, the accumulation of more acidic isoforms precedes the accumulation of alkaline ones.

[Effects of antibodies to lysosomal enzymes on the course of experimental burn shock]

On the model of burn shock in rats, the influence of antibodies to lysosomal enzymes has been studied in respect to the cathepsin D activity, oxygen regimen, acid-base equilibrium in blood, and animal survival. It has been shown that the antibodies inactivate the cathepsin D activity which is increased in burn shock. Because of the decreased cardiodepressant action of the lysosomal enzymes, the blood circulation improves, the manifestations of hypoxia and metabolic acidosis are attenuated. The results obtained confirm an important role of the lysosomal in the pathogenesis of bur, shock and permit one to consider its therapy using antibodies to the lysosomal enzymes to be promising.

[Protective effect of thyrotropin-releasing hormone against lipid peroxidation injury during traumatic shock in rats]

In this paper are reported the results of a study on the protective effect of thyrotropin-releasing hormone (TRH, 0.5mg/100g) against lipid peroxidation injury during traumatic shock in rats. Cardiac and lung tissue malondialdehyde (MDA) contents in TRH group were lower than those in normal saline (NS) group (P less than 0.05) 1 hr after shock. Cardiac, liver, kidney and lung tissue MDA contents 3 hrs after shock and liver and kidney tissue MDA contents 5 hrs after shock in TRH group were lower than those in NS group (P less than 0.05). TRH could increase the endogenous superoxide dismutase (SOD) activities in vital organ tissues. 5 hrs after shock, liver, kidney and lung tissue SOD activities in TRH group were still higher than those in NS group (P less than 0.05). In addition, TRH could depress the elevation of plasma MDA content, raise blood pressure and 24-hr survival rate of the animals in shock. It was found that TRH has not the effect of directly scavenging oxygen-derived free radicals in vitro. The results demonstrated that the beneficial effects of TRH during traumatic shock may be related to its protection against lipid peroxidation injury in vital organ tissues.

[Postaggressive metabolism in severe mechanical trauma]

Posttraumatic adaptive reactions are divided by the authors into three periods: the period of "urgent" adaptation (1-2 days), intermediate period (3-7 days) and the period of "long-term" adaptation (after 7 days). The period of "urgent" adaptation may be considered to be more favorable for surgical interventions under conditions of adequate anesthesiological maintenance. A critical associated trauma unlike an isolated one was found to cause more pronounced and continuous strain of the endocrine and metabolic reactions related with the "urgent" adaptation which influences the frequency of complications and lethal outcomes.

Effect of lethal scald on the mechanisms of acute-phase protein synthesis in rat liver

Acute-phase protein (APR) synthesis was studied under conditions in which the acute-phase response to a sublethal scald was interrupted at the onset of APR synthesis by the infliction of a second scald that overwhelmed the defense mechanisms. The rate of APR synthesis increased shortly after the second scald and then declined rapidly to the control level. At this time point, APR messenger RNA (mRNA) concentrations exceeded severalfold the control values, whereas the APR gene transcription rates fell to the control level. These mRNAs were active in APR synthesis in a cell-free system, as well as in hepatocytes grown in a standard culture medium. These results and those demonstrating a drop in the free amino acid pool level in the liver after the second scald suggested that the lethal outcome was preceded by an impaired supply of liver cells with amino acids and resulting inhibition of APR mRNA translation. Changes in amino acid transport were considered to occur secondarily to those causing hypovolemia and circulatory shock.

Physiologic response to traumatic shock

Traumatic injury results in major physiologic alterations that begin at the time of injury and persist until recovery is complete. The response of the body is divided into two phases--the acute phase and the flow phase. The acute phase is characterized by shock with changes in hormone concentration. These hormones, either alone or in combination, result in lipolysis, amino acid release, gluconeogenesis,, and glycolysis. The flow phase of injury is a catabolic process that is characterized by an increased protein metabolism. Hypermetabolism and increased nitrogen losses are seen. The magnitude of these alterations is directly related to the severity of injury. Tissues with the highest oxygen consumption are more susceptible to injury and death. Cellular function does not depend on oxygen alone but also on the ability of the cells to use available oxygen. If the body is unable to compensate through biochemical, hormonal, and metabolic activities, an irreversible state results unless appropriate interventions are instituted promptly.

[Lipid peroxidation and the phospholipid composition of the liver plasma membranes in rabbits in traumatic shock and their pharmacological correction]

Changes in peroxidation of hepatic tissue lipids were studied in experiments on rabbits with Cannon's traumatic shock according to products reacting with thiobarbituric acid. The lipid composition of hepatocyte plasma membranes was studied by thin-layer chromatography. The levels of lipid peroxidation products and the ratio of phospholipid fractions changed depending on the stage of the process. Administration of superoxide dismutase in the initial periods of shock reduced the raised level of products reacting with thiobarbituric acid and maintained the ratio of phospholipid fractions in the hepatocyte plasma membrane at the initial level.

Changes of leukotrienes in rabbits subjected to tourniquet shock

Rabbits were used as a traumatic shock model, and the right femoral root was fastened tightly with a tourniquet for human children for 24 hours. The amounts of LTB4, LTD4 and LTE4 in the blood and muscle were measured just before unfastening and 3, 6 and 12 hours after unfastening. After unfastening, the rabbits showed a gradual decline of blood pressure, and one died 7 hours after unfastening. LTB4 levels in the blood and muscle were within the levels of the control rabbits throughout the experimental period. On the contrary, LTD4 levels in the blood increased just before and 6 and 12 hours after unfastening. LTD4 levels in the muscle also increased at the fastened site just before and 3 and 6 hours after unfastening. LTE4 levels in the blood increased 3 hours, and those in the muscle 3 and 6 hours after unfastening. These results suggest that peptide leukotrienes may contribute to the pathogenesis of traumatic shock.

[The content of glycogen and its fractions in human hepatocytes in traumatic disease]

A cytofluorometric study was made of the total glycogen and its of fractions in liver cells of patients with hard mechanic trauma with or without intoxication. For studying glycogen dynamics in the course of traumatic illness, the aspiration biopsy material was obtained (30 patients) using repeated liver biopsy of one and the same patient. The total glycogen was found to change insignificantly in liver cells of patients with traumatic illness, both under favourable conditions and with intoxication, and at the normal level. The labile glycogen fraction in liver cells of patients with traumatic illness without intoxication is contained almost at the normal level (80-95%) of the total glycogen and is not changed for a long time. At that time the relative content of the labile glycogen fraction decreases appreciably in some cases to 45-50% due to intoxication development. A relative content of the labile glycogen fraction in hepatocytes with hard mechanical intoxication correlates well with the degree of intoxication. This makes hepatocyte glycogen microfluorometry a diagnostic tool in measuring the functional state of liver in the course of intoxication.

[Effectiveness of the elimination of lipid peroxidation products in various methods of detoxication therapy of patients with traumatic shock]

The shockogenous trauma is followed by a considerable accumulation of lipid peroxidation products in the patient's organism. The most effective of all the measures used for the detoxication was found to be extracorporal use of the donor spleen which resulted in lower content of lipid peroxidation products in blood plasma immediately after the procedure. The maximum effect was observed 1 hour later and persisted during one day after treatment.

[Energy metabolism in skeletal muscles in experimental traumatic shock]

Content of ATP and adenylate nucleotides was not markedly altered in rats during a traumatic shock induced by Cannon's procedure involving an impairment of skeletal muscles. Energy potential and content of creatine phosphate were only slightly decreased in these tissues, while the level of lactate and the lactate/pyruvate ratio were increased at the terminal phase.

[Experience with extracorporeal use of xenospleen in patients with traumatic shock]

The article presents results of using the extracorporal connection with the donor (porcine) spleen (ECCDS) for the treatment of 14 patients with critical mechanical traumas and their complications. An experience with 30 ECCDS-s has shown them to possess a pronounced detoxicating and immunomodulatory effect followed by a positive clinical result. In 6 cases of ECCDS a temporary chill was noted. There were no other complications.

[Effects of urinastatin on an energy metabolism disorder during shock]

We investigated the effect of urinastatin on energy metabolism disorder during shock. Intravenous administration of urinastatin at the dose of 50,000 U/kg ameliorated the decrease in total adenine nucleotide (TA) levels and in energy charge (EC) of liver and pancreas during traumatic-shock induced by the Noble-Collip drum method in rats. Urinastatin, at a concentration of 3,000 U/ml, suppressed the decrease in EC of rat liver slices exposed to the medium including 10% serum obtained from traumatic-shock rats. Aprotinin showed a similar effect. Depression in respiratory activity of liver mitochondria exposed to the shock rat serum was also ameliorated by 1,000 U/ml of urinastatin, but aprotinin failed to reverse this depression. In the isolated rat livers perfused with normal rat serum, urinastatin at the concentration of 3,000 U/ml did not affect ATP and TA levels and EC. These results suggest that, unlike aprotinin, urinastatin ameliorates the depression of energy metabolism in liver during shock without affecting normal energy metabolism, probably by antagonizing the actions of depressant factors released into blood during the shock state and by protecting against the decrease in the adenine nucleotide pool.

[Effect of enkephalins on the energy potential of the rat liver and cerebral cortex during an early period of traumatic shock]

The experiments were performed on 86 white male rats, weighing 180-220 g. The animals with traumatic shock revealed a decrease in ATP concentration and a rise in ADP and AMP levels in the brain cortex and hepatic tissue, resulting in the energy charge reduction. The injection of synthetic leu-enkephalin analog D-ala2-arg6-leu-enkephalin to animals with traumatic shock led to energy charge normalization in the brain cortex and increase in hepatic tissue. The mechanisms of enkephalin effect on the energy metabolism during shock are discussed.

[Changes in the met- and leu-enkephalin levels in the rat brain during burn shock]

The dynamics of met-and leu-enkephalin content in the brain cortex and hypothalamus of rats with severe burn shock caused by 50% burns by boiling water were studied. A tendency towards burn-induced growth in leu-enkephalin hypothalamus level was observed, with the content of met-and leu-enkephalins in the hypothalamus significantly increasing 30 min later. Met-enkephalin content in the brain cortex also rises. 2 hours later the changes are less pronounced, with met-enkephalin hypothalamus level remaining elevated. The adaptive nature of changes, mobilization of endogenous anti-pain defensive mechanisms in severe burn shock and the role of hypothalamus structures in this process are suggested.

[Effect of cytochrome c on bioenergetic processes in the liver in severe compression trauma]

After severe mechanical trauma of rat soft tissue content of ATP, total adenine nucleotides, amounts of "energy charge" of the adenine nucleotide system and cytochrome c were decreased in liver tissue, while content of AMP and Pi was increased. Parenteral administration of cytochrome c at a dose of 10 mg/kg into animals after the trauma normalized the energy processes in liver tissue and increased the content of endogenous cytochrome c.

[Characteristics of various parameters of homeostasis in suppurative-septic complications of severe trauma]

In pyo-septic complications of a severe mechanical isolated trauma there are regular changes in homeostasis. The direction and degree of the changes of biochemical and immunological parameters within the first 3 days may be a prognostic criterion of the clinical course of the postshock period whether complicated or noncomplicated.

[Correction of lipid peroxidation disorders in experimental traumatic shock using the antioxidant ionol]

The level of certain parameters of lipid peroxidation and the activity of lysosome hydrolases were studied on the shock model in rats. It was established that the traumatic shock in the experiment is accompanied by the growth of the level of over-oxidation products (malonic dialdehyde, diene conjugates), the rate of erythrocyte hemolysis as well as by an increase in the hydrolase activity. Administration of ionol (60 mg/kg) inhibits the higher activity of radical-free lipid oxidation, decreases the damage of membrane structure and the metabolism disturbance.

Cimetidine kinetics during resuscitation from burn shock

Severely burned patients suffer from rapidly changing metabolic and hemodynamic abnormalities that could alter drug kinetics. The kinetics of cimetidine, commonly used in the prophylaxis of acute stress erosions, were studied during fluid resuscitation of 11 patients with mean burn sizes of 45% total body surface area. Six patients were studied after the completion of fluid resuscitation. Total clearance, steady-state volume of distribution, and cimetidine t1/2 did not change between the early period after burn and after fluid resuscitation, but before the completion of fluid resuscitation patients had lower renal and greater nonrenal cimetidine clearance than after resuscitation. The increase in nonrenal cimetidine clearance resulted in decreased urinary recovery of unchanged drug, 50.7 +/- 14% during fluid resuscitation and 81.0% +/- 6% after resuscitation.

[Energy potential of the liver in the early period of the crush syndrome]

Experiments on rats with a severe compression trauma were made to study the liver content of ATP, ADP, AMP and inorganic phosphate. It was established that in the early period of the crush syndrome, the rats manifested pronounced changes in the energy potential of the liver, attesting to the disturbances of the processes of energy production in that vitally important organ. It is assumed that liver ischemia and direct action on the liver of toxic factors of the protein nature circulating in the blood may be one of the reasons for the disturbances under discussion.

[Dynamics of changes in pulmonary catecholamine content and lipid fatty acid composition in traumatic shock]

The content of noradrenaline in the lungs, pulmonary arteries and veins was found to be reduced at definite stages of traumatic shock. At the same time the level of oleic acids was decreased in pulmonary lipid fractions. The content of adrenaline rose in the pulmonary arteries and veins, and it was high in the blood collected from the right atrium as compared to the blood from the carotid artery. It is assumed that the changes in the content of fatty acids are linked with those occurring in lung catecholamine metabolism.

Studies of hemorrhagic and traumatic shock influence on liver oxygen tension: effects of a single large dose of dexamethasone

Liver surface oxygen tension in response to hemorrhagic shock (hs) and to combined hemorrhagic-traumatic shock (hts) as well as to hemorrhagic-traumatic shock with glucocorticoid application ( htsc ) has been studied using male rats (Wistar strain, 250-300 g b.w.). The animals were anaesthetized by i.p. injection of ketamine/xylazine. All animals were bled through a catheter inserted into the vena jugularis until a hypotension of 40 mm Hg mean arterial blood pressure (MAP) was attained. The hts rats were traumatized by fracturing the left tibia and crushing the adjacent muscle tissue with 45 N/2.25 cm2 for 5 minutes. The htsc animals were traumatized and treated with a single injection of a large pharmacological dose of dexamethasone (6-8 mg/kg b.w.). Initial surface Po2 of the liver was higher than published by others (29 +/- 7 mm Hg) probably due to the narcotic agents. Maximal blood withdrawal was 24.4 +/- 2.2 ml/kg b.w. for hs, 17.9 +/- 3.8 ml/kg b.w. for hts and 20.6 +/- 4.5 ml/kg b.w. for htsc rats. Liver surface Po2 decreased to zero mm Hg in response to hypovolemic hypotension in all rats. Retransfusion of the shed blood caused a MAP and surface Po2 increase to only about half of the initial levels in hts and htsc rats while in hs animals the initial values were approximated. The hts and htsc rats showed signs of progressive hypotension to about 45 mm Hg MAP within 90 minutes post retransfusion. Dexamethasone improved the arterial pH to 7.15 compared with 7.05 of the control. Pao2 was elevated to 60 mm Hg vs. 49 mm Hg of the control animals. The beneficial influence of glucocorticoids on liver surface Po2 has not been substantiated as would have been desirable for the patient. Nevertheless, from a physiological standpoint a positive trend in the liver O2 supply has been evaluated as a small right shift of the surface Po2 histogram as well as the blood gas and pH data.

Effect of thermal injury on energy metabolism, substrate kinetics, and hormonal concentrations

We have used a chronic dog model to study the kinetic aspects of the metabolic response to thermal injury. In order to interpret the kinetic data in the context of the overall response to injury, we also determined certain cardiovascular parameters as well as selected hormonal concentrations. We used a paired study design: each animal was studied twice before injury and then at 5 and 7 days following injury. The burn was induced while the animals were deeply anesthetized with sodium pentobarbital (30-35 mg/kg) but all studies were done in awake, unrestrained dogs using tracer methodology and both radiolabeled and stable isotopes. The burn induced a hyperdynamic state, with significant elevations in cardiac output, heart rate, and metabolic rate. The free fatty acid (FFA), glycerol and glucose flux rates were all elevated, as was the rate of production of urea. The increase in resting metabolic rate was due to comparable increases in the rates of oxidation of carbohydrate, fat, and protein. We found the responses of this canine burn model to closely resemble the human response to injury, and thus this model will be useful as a tool to elucidate some of the mechanisms responsible for the response to injury.