Free Radical Oxidation Processes Research Articles

Effect of contact surfaces on the thermal and photooxidation of dehydrated castor oil

The effect of stainless steel, glass, zirconium and titanium enamel surfaces on the thermal and photooxidative toughening mechanism of dehydrated castor oil films deposited on these surfaces was investigated using different analytical and spectroscopic methods. The conjugated and non-conjugated double bonds were identified and quantified using both Raman spectroscopy and 1D and 2D NMR spectroscopy. The disappearance of the double bonds in thermally oxidised oil-on-surface films was shown to be concomitant with the formation of hydroperoxides (determined by iodometric titration). The type of the surface had a major effect on the rate of thermal oxidation of the oil, but all of the surfaces examined had resulted in a significantly higher rate of oxidation compared to that of the neat oil. The highest effect was exhibited by the stainless steel surface followed by zirconium enamel, titanium enamel and glass. The rate of thermal oxidation of the oil-on-steel surface (at 100°C, based on peroxide values) was more than five times faster than that of oil-on-glass and more than 21 times faster than the neat oil when compared under similar thermal oxidative conditions. The rate of photooxidation at 60°C of oil-on-steel films was found to be about one and half times faster than their rate of thermal oxidation at the same temperature. Results from absorbance reflectance infrared microscopy with line scans taken across the depth of thermally oxidised oil-on-steel films suggest that the thermal oxidative toughening mechanism of the oil occurs by two different reaction pathways with the film outermost layers, i.e. furthest away from the steel surface, oxidising through a traditional free radical oxidation process involving the formation of various oxygenated products formed from the decomposition of allylic hydroperoxides, whereas, in the deeper layers closer to the steel surface, crosslinking reactions predominate.

THE INFLUENCE OF OXYTOCIN ON PRO- AND ANTIOXIDANT STATE AT DIABETIC ANIMALS

The aim of the investigation was to study the influence of course central and peripheral oxytocinintroduction on the state of pro- and antioxidant systems in healthy and diabetic animals. It isfound out that oxytocin introduction promotes the decrease of the activity of free radical oxidation process in erythrocytes in healthy animals. In diabetic animals, which were administered oxytocin by, the significant decrease of the content of primary, secondary and definitive products of peroxide lipid acidification has been observed. It has been registered on the background of the increase of catalase and glutationreductase activities and the increase of α-tocopherol content. These changes of antioxidant components activity of erythrocytes defense were actually higher in the process of central introduction of neuropeptide. The results observed show the antioxidant activity of oxytocin that may be realized through the intensification of antioxidant defense processes

Pro198Leu Polymorphism of GPx-1 Gene and Activity of Erythrocytic Glutathione Peroxidase and Lipid Peroxidation Products

We studied the relationship between the GPx-1 gene Pro198Leu polymorphism genotype and activity of free-radical processes. In patients with documented CHD, the content of lipoperoxides and MDA in LDL, activity of glutathione peroxidase in erythrocytes, and genotype of GPx-1 gene Pro198Leu polymorphism were determined. In carriers of the minor allele, activity of glutathione peroxidase in erythrocytes was lower by 17% than in wild allele homozygotes, while the content of lipoperoxides and MDA in LDL was higher by 74 and 27%, respectively. We concluded than free-radical oxidation processes are more pronounced in carriers of the minor allele of GPx-1 gene Pro198Leu polymorphism.

Correcting the antioxidant status of newborn calves for forming higher colostral immunity

It has been established that correcting the metabolic status 15–60 min after birth (before the first ingestion of colostrum), directed at stabilizing processes of free-radical oxidation and acid-base state in newborn calves, promotes the creation of a higher level of colostral immunity and is the basis for reducing the development of neonatal diseases.

To the Pathogenesis of Heart Failure in Pancreonecrosis: Experimental Study

Objective: to evaluate the severity of a cardiac lesion in pancreonecrosis and possible mechanisms of pancreatogenic heart failure. Materials and methods. Experiments were made on albino male Wistar rats. In 32 animals anesthetized with ether, pancreonecrosis was simulated by injecting autobile (0.15 ml/kg) into the pancreas with later ligation of the common bile duct. In 18 animals, immunosuppression was induced by triple hydrocortisone administrations and pancreonecrosis was then simulated. Thirty intact anesthetized rats served as a control. Cardiac contractility was studied using an isolated isovolumi-cally contracting heart preparation, by recording the force and velocity indices of contractility, glucose uptake, and enzymatic leakage into the coronary stream. The severity of endotoxemia, the rate of free radical processes, and the serum levels of cardiospecific and pancreatic enzymes were estimated. Results. Pancreonecrosis induces a cardiac lesion, followed by its contractile depression and increased glucose uptake per performed function unit. There is an enhanced susceptibility of isolated hearts to hypoxia, reoxygenation, and exogenous calcium. The hearts of immunosuppressed animals are damaged to a greater extent. Conclusion. Activation of free radical oxidative processes, inadequacy of the antioxidant defense system, impaired cardiac bioenergy, endotoxemia, and depressed phagocytosis have been established to be the leading pathogenetic factors of pancreatogenic myocardial depression. Key words: pancreonecrosis, pathogenesis of heart failure.

Effects of Prenatal Stress on Free-Radical Lipid and Protein Oxidation and Superoxide Dismutase Activity in Cerebral Cortex Neurons and Neuroglia in the Rat Brain

The processes of free-radical oxidation of proteins and lipids and superoxide dismutase activity were studied in neurons and neuroglia of the cerebral cortex in rats during ontogenesis and after prenatal stress. Regardless of age, normal animals were found to have higher levels of free-radical lipid and protein oxidation in neurons than in glia. This same pattern was also observed in relation to superoxide dismutase. After prenatal stress, the level of free-radical lipid oxidation decreased in 20-day-old rats in both neurons and neuroglia. Conversely, the level of free-radical protein oxidation products increased only in neurons, by an average factor of four. Superoxide dismutase activity in animals subjected to prenatal stress decreased significantly in neurons but did not change in neuroglia.

Melatonin: Quantum-chemical and biochemical investigation of antioxidant activity

Experimental and theoretical investigation of the antioxidant activity of melatonin is carried out. The theoretical approach comprises the evaluation of several appropriate descriptors of scavenging activity with the help of quantum-chemistry methods. The values obtained are compared with available data for substances with established antioxidant properties. One of the most widely used markers for in vivo free radical oxidation processes is malondialdehyde (MDA) as an end product of membrane lipid peroxidation. Experimental support of the computed scavenging parameters is provided by estimation of the effect of supplementary melatonin therapy on the plasma levels of MDA in CRF patients on maintenance HD therapy. Different reaction paths have been considered and related to the obtained data, allowing speculations about the reaction mechanism and the antioxidant potential of melatonin for practical purposes.

Hepatoprotective Activity of a Complex Compound of 5-Hydroxy-6-Methyluracil and Succinic Acid in Experimental Peritonitis

Objective: to evaluate the hepatoprotective efficacy of a complex compound of 5-hydroxy-6-methyluracil and succinic acid in experimental peritonitis. Materials and methods. Experiments were carried out on 48 male albino rats in which peritonitis was simulated via intraperitoneal administration of 7% fecal suspension in a dose of 0.6 ml per 100 g bodyweight. The rate of free radical oxidation processes, the activity of antioxidative protection, the degree of endogenous intoxication and cytolytic syndrome, and the effect of the test compound on these parameters were estimated in the experiment. Results. With the development of an abdominal inflammatory process, there were increases in rates of endogenous intoxication and free radical oxidation (FRO), a change in the activity of antioxidative protection enzymes, and a reduction in the levels of ceruloplasmin and sulfahydryl groups. The complex compound, that comprised 5-hydroxy-6-methyluracil and succinic acid used as monotherapy, reduced the degree of endogenous intoxication, FRO, and lipid peroxidation-antioxidative defense system imbalance. Conclusion. The experimental data suggest that the use of the complex compound containing succinic acid and 5-hydroxy-6-methy-luracil is pathogenetically warranted. Key words: peritonitis, lipid peroxidation, antioxidants, succinic acid, pyrim-idine derivatives.

Pathogenesis of Intoxication in Hemorrhagic Hypotension (Experimental Study)

Objective: to reveal the toxicity of unpaired abdominal organs and portal venous blood, which would appraise the actual contribution of each organ to the development of endotoxemia in the presence of hemorrhagic hypotension. Materials and methods: experiments were carried out on 50 outbred albino male rats and hemorrhagic hypotension was simulated in 40 animals. Following 15, 30, and 60 min and 2 hours, the liver, spleen, and intestine were taken and used to prepare homogenates whose toxicity was studied by the procedure developed by N. I. Gabriyelyan et al. The levels of oligopeptides (OP) were measured in the portal venous blood by the Lowry method and those of low and median molecular-weight substances (LMMWS) were separately determined in the whole blood and plasma by chemiluminescence. The significance of mean value differences was determined using the paired Student test and the unpaired Wilcoxon test. Results. The maximum LMMWS increment was established to be in the homogenates of the bowel, its large portion in particular. However, a decrease in LMMWS levels was revealed in later periods, which was indicative of a rapid intestinal adaptation to hypoperfusion. The progressive rise in the portal venous blood concentrations of LMMWS and OP was caused by altered intestinal wall permeability and bacterial translocation, followed by hepatic damage with the substantial activation of the prooxidative system and with the concurrent decrease in the antioxidative activity, as well as in the phagocytic activity of leukocytes. The spleen and liver showed the increased compensatory biotransformation of endotoxins and their elimination from the body. In the late periods, these organs acted as a source of LMMWS. At the same time, no rise and a further reduction in leukocytic phagocytic activity suggest that the latter is inhibited by portal venous blood toxins. Conclusion: Evaluation of the time course of changes in the values of intoxication, the rate of free radical oxidation processes, the phagocytic activity of leukocytes, as well as the relationship of these parameters are of practical value for the determination of further prognosis in hemorrhagic hypotension. Key words: hemorrhagic hypotension, low and median molecular-weight substances, oligopeptides, free radical oxidation, portal vein.

Effects of combined treatment with heavy metals and piracetam on learning and memory in rats

A negative influence of heavy metals on many sys-tems of the body including CNS is well known.Employees in the industry of heavy metals suffer fromneurodegenerative disorders, including Alzheimer’sand Parkinson’s diseases [1]. Children who live inindustrial cities exhibit signs of retardation of neurop-sychic development, including memory, learning,motor function, and speech, as well as a decrease in IQand other alterations [2–4]. Neuropsychotropic drugs,particularly, nootropics, which enhance learning andmemory, are widely used [5].Studies on the effects of heavy metals and nootropicdrugs on the CNS have been performed independentlyfrom one another, though combined effects of thesesubstances could be supposed. Specifically, the antiox-idant system of the body may be a target for combinedaction of heavy metals and nootropics. The antioxidantsystem plays an important role in the response of theCNS to stress, because it prevents excessive activationof free radical oxidation processes, which damage cellmembranes and contribute to progression of pathol-ogies that influence many functions. Cells of theCNS are the most vulnerable to free radical proc esses[6–10].It has been reported recently that neurotoxic effectsof heavy metals are related to their ability to inducelipid peroxidation and change the activity of mem-brane-bound enzymes [8, 11]. On the other hand, themechanism of nootropic action is determined by theirantioxidant and membrane-protective effects [5, 7].Melatonin, a hormone of the pineal gland with nootro-pic properties [12], decreases free radical damage ofneurons induced by lead [13]. The above data suggestcombined effects of nootropics and heavy metals on theantioxidant system of the brain.The purpose of this study was to investigate theeffects of the reference nootropic drug piracetam andsalts of heavy metals on the conditioning of activeavoidance response based on electric footshock rein-forcement. This response was used as an animal modelof learning and memory.Fourteen groups of male white nonlinear rats weigh-ing 160–200 g at the beginning of the experiment wereused for the study. Group 1 was used as a control forgroups 2–10, and group 11 was used as a control forgroups 12–14 (table). Groups 1–10 consisted of 11 ratseach and groups 11–14 consisted of 12 rats each. Theexperimental chamber was divided into two equal com-partments by a wall with a hole. Avoidance condition-ing was performed using the following protocol. Eachtraining trial began with 10-s presentation of an acous-tic conditioned stimulus followed by electric footshock(0.5–0.7 mA) through the electrified floor of the cham-ber. The stimuli were presented in the compartmentwhere the rat was located. If the rat did not enter thesafe compartment of the chamber during 10 s, bothstimuli were turned off. The stimuli were presentedagain after a 30-s interval. If the rat entered the adjacentcompartment during the sound presentation, it avoidedthe footshock, and the sound was turned off. If the ratentered the adjacent compartment during the foot-shock, both stimuli were turned off. Each training ses-sion consisted of 25 presentations of the stimuli.During five experimental days, the rats were intrap-eritoneally injected with one of the solutions of heavymetals and a solution of piracetam at a dose of300 mg/kg 4 h and 0.5 h prior to avoidance condition-ing, respectively. Water solutions of heavy metal saltswere used at the following concentrations: 10

Clinical results of the application of perftoran for the treatment of odontogenous abcesses and phlegmons in the maxillofacial region

The study was carried out to ascertain the effects of perftoran in the treatment of facial and Dupuytren's phlegmons with simultaneous estimation of the general reaction in humans. Seventy-six patients with facial or Dupuytren's phlegmons were divided into 2 groups, one with mild and the other with a severe course of the inflammatory process. Each group was subdivided into 2 subgroups: one control group with "traditional" treatment and one study group where the traditional treatment was supplemented with perftoran. Perftoran was given to both study groups (1-3 ml/kg body weight, single intravenous injection) immediately after surgery plus further daily local wound treatment with perftoran until the end of exudation. The condition of the purulent wound and its reparative processes, the state of free-radical oxidation processes, antihypoxia and effects of perftoran were evaluated at various treatment stages (the moment of surgically opening the phlegmon, on the 1st, 3rd and 7th postoperative days). Perftoran considerably decreased the tissue hypoxia as well as the transaminase and creatinine levels in blood serum. Perftoran helped to decrease the intoxication indices, hypoxaemia by 10-15%, to speed local wound healing by 2-5 days and to shorten the time of hospital treatment by 3-6 days on average. The many positive effects of perftoran on the clinical course of the disease and on a series of homeostatic parameters allow us to recommend that this drug to be added for treating patients having odontogenous phlegmons in the maxillofacial region.

Aerobic metabolism of vitamin E by marine bacteria: Interaction with free radical oxidation (autoxidation) processes

The degradation of vitamin E by aerobic bacterial communities, isolated from marine sediment and microbial mat samples, was investigated. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) profiles and cloning/sequencing experiments revealed that biodegradation of vitamin E in sediments is mainly carried out by strains belonging to the genera Idiomarina and Bacillus, for which the DGGE pattern matched the pattern obtained from the second sediment subculture. Biodegradation appeared to involve an initial ω-oxidation of the isoprenoid side chain and subsequent β-oxidation, affording 2,5,7,8-tetramethyl-2(2′-carboxyethyl)-6-hydroxychroman (α-CEHC). This compound was not accumulated at the end of growth, showing that the bacterial degradation of vitamin E is not limited to the isoprenoid side chain. In cultures still containing residual sediment, the presence of metabolites with a shortened side chain and opened chroman ring (e.g., α-tocopheronolactone and α-tocopherylhydroquinonolactone) attested to the simultaneous involvement of biodegradation and autoxidation. The induction of autoxidation during these incubations was attributed to some of the sediment components, which could act as catalysts for free radical reactions. In oxic environments, the combination of free radical oxidation and aerobic biodegradation should result in very rapid degradation of vitamin E. Different pathways are proposed to explain the formation of the different compounds resulting from these interactions.

Desferal-Induced Inhibition of Lipid Peroxidation Processes in Experimental Pancreatic Necrosis

Objective: To experimentally reduce the activity of hyperoxidative processes in experimental pancreatic necrosis, by pread-ministering desferal as a Fe2+ chelator, and to determine the implication of ionized iron in the intensification of endotoxi-cosis, one of the leading risk factors of multiple organ dysfunctions. Subjects and methods. An experiment was carried out in 60 albino male rats in which pancreatic necrosis was simulated, by administering 0.25 ml of autobile per kg into the pancreas and by ligating the common bile duct just at the mouth of the duodenum. The parameters of endogenous intoxication (the levels of oligopeptides) and the rate of free radical oxidation processes were estimated in the experiment. The impact of prophylactic desferal administration on the parameters was also evaluated. Results. It has been ascertained that pread-ministration (3 hours before the simulation of pancreatic necrosis) of desferal in a dose of 80 mg/kg can prevent the potentiation of LPO processes, which substantially reduces endotoxicosis that develops in pancreatic necrosis. Conclusion. The findings give grounds to use desferal in clinical practice as a pathogenetically warranted agent to perform an abolishing therapy for one of the pathogenetic factors (oxidative stress) in acute progressive pancreatitis.

Effects of α1-acid glycoprotein on free radical oxidation processes in experimental liver failure

The effects of alpha1-acid glycoprotein (2 intraperitoneal injections in a total dose of 300 mg/kg) on free radical oxidation during liver failure were studied in 53 outbred rats. On day 3 of liver failure, glycoprotein reduced plasma concentrations of free radical oxidation products, elevated the antioxidant potential of the plasma and liver and kidney homogenates, and restored functional reserve and capacity of leukocytes to generation of oxygen radicals.

Thermal chemiluminescence of fibrous proteins

Thermal chemiluminescence (TCL) from the fibrous proteins wool and feather keratin, silk fibroin and Type I collagen is reported for the first time. The proteins all emit TCL when heated in the atmosphere of O 2 or N 2 in the range 40–220 °C. Plotting non-isothermal CL data in O 2 in Arrhenius format showed an increase in the activation energy at temperatures in the range 129–161 °C for each protein. This may indicate that a different free radical oxidation process operates when the mobility of the amorphous phase of the protein is increased above its T g. Wool, silk and collagen exhibited a luminescence peak at 130 °C (with feather keratin at 145 °C) during non-isothermal CL experiments in N 2, similar to that observed in many synthetic polymers and characteristic of polymer hydroperoxides.

Time Course of Changes in the Concentration of Peroxides and Superoxide Dismutase in Females with Gestosis in the Perioperative Period

Objective: to study the level of peroxides and the activity of superoxide dismutase (SOD) in females with gestosis in the perioperative period. Materials and methods: 85 females in whom delivery had been performed under spinal anesthesia using conventional perioperative intensive care were examined. A control group comprised 30 females with uncomplicated pregnancy; Group 1 included 26 females with moderate gestosis; Group 2 consisted of 29 females with severe gestosis. The severity of gestosis was determined by means of the Goecke scale that had been modified by G. M. Savelyeva. The groups of the examinees were matched by height, weight, age, and gender. Results: there is intensification of free radical processes and a standard adaptive response of the antioxidative system forms in the pregnant females exposed to surgical delivery under spinal anesthesia. In dynamics, this reaction is characterized by a certain pattern: the maximum activation on the first postoperative day, some depletion on day 3, and recovery of compensatory capacities on day 5. The antioxidative system of the females with uncomplicated pregnancy generally shows a balanced response to activated free radical processes during surgical delivery and in the postoperative period. There is stress in moderate gestosis-complicated pregnancy and depletion of the antiox-idative system in severely progressive gestosis, which diminishes the body’s adaptive capacities and leads to the formation of chronic oxidative stress as a leading factor of the pathogenesis of the disease. Imbalance between free radical oxidation processes and the antioxidative system increases when surgical delivery is performed. In the females with moderate gestosis, oxidative stress may be characterized as subcompensated with a moderate increase in the concentration of peroxides in the intra- and postoperative period, as compared with those with physiological pregnancy. Conclusion. Severe gestosis is characterized by a decompensated stress with a pronounced increase in the level of peroxides before and during surgical delivery and within 5 postoperative days.

Correction of Hypoxia and Free Radical Oxidation Processes in Gastroduodenal Hemorrhages

The present investigation was to study the clinical efficacy of the substrate antihypoxant-antioxidant Reamberin used in the correction of tissue hypoxia and free radical oxidation (FRO) in patients with severe blood loss of ulcerous etiology. The paper presents the results of the investigation of Reamberin used in the therapy of posthemorrhagic hypoxia, by simultaneously evaluating metabolism and the parameters of lipid peroxidation (LPO) and the antioxidative system (AOS) in patients with ulcerative gastroduodenal hemorrhage (UGDH). Materials and methods. Thirty-six patients with UGDH with a circulating blood volume (CBV) deficit of 30—40% and a globular volume of 50—60% were examined. Systemic hemodynamics was examined by the integral body theography method by means of a Diamant rheoanalyzer. The values of blood oxygen-transport function were determined and calculated. For rapid expression and evaluation of the summary state of FRO, a procedure for the recording of activated H2O2 chemiluminescence was used in the presence of Fe2+. Metabolic disturbances were judged from the concentration of lactate and glucose. Results. Acute blood loss of ulcerous etiology has been found to cause significant systemic hemodynamic and microcirculatory disorders and impairments of metabolism, oxygen balance, and tissue perfusion and to intensify FRO and LPO processes, and the use of 1.5% Reamberin in a volume of 800 ml/day substantially reduces the degree of specific cell metabolic disturbances in critical conditions, such as tissue hypoxia, mitochondrial dysfunction, FRO activation, LPO-AOS imbalance. Conclusion. Inclusion of Reamberin in the intensive care of acute blood loss diminishes the manifestations of tissue hypoxia and improves oxygen delivery and consumption. The agent activates the antioxidative system, inhibits LPO processes in the ischemic tissues, and reduces the severity of pathological effects of hypoxia during reperfusion and reoxygenation.

Effect of sugars on the development of oxidative stress induced by hypothermia in potato plants expressing yeast invertase gene

The influence of sugars on the development of oxidative stress induced by hypothermia was investigated in the leaves of two genotypes of potato (Solanum tuberosum L.) grown in vitro on the Murashige and Skoog medium supplemented with 2% sucrose. We used wild-type plants of potato, cv. Desiree, and potato plants expressing a yeast invertase gene under the control of the B33 class I patatin promoter and carrying a sequence of proteinase inhibitor II leader peptide for the apoplastic enzyme localization. At temperature of 22°C optimal for growth, expression of the yeast invertase gene in the leaves of transformed plants brought about a modification in the carbohydrate metabolism manifested in the activation of acid forms of invertase and accumulation of intracellular sugars (predominantly of sucrose because of its resynthesis). The exposure of plants to light under prolonged hypothermia (5°C, 6 days) activated all the forms of invertase (predominantly of acid invertase) and induced accumulation of sugars. In the leaves of potato expressing the yeast invertase gene, these processes were more intense. Under chilling, superoxide dismutase activity and the rate of lipid peroxidation in the leaves of investigated potato genotypes depended on the level of accumulated intracellular sugars. It was concluded that sugars play an important role as stabilizers of cellular membranes and scavengers of reactive oxygen species decelerating the processes of free radical oxidation of biomolecules upon the development of oxidative stress induced by hypothermia.

Free radical oxidation (autoxidation) of alkenones and other lipids in cells of Emiliania huxleyi

Cells of the coccolithophorid Emiliania huxleyi strain CS-57 grown under an atmosphere of air + 0.5% CO 2 showed oxidative damage after 10 days growth with concomitant and major changes to the lipid composition. The fatty acid profile was strongly altered and lacked appreciable amounts of the polyunsaturated fatty acids (PUFA: C 18:5, C 18:3 and C 22:6) typical of healthy cells. Oxidation products of these PUFA could not be detected, but monounsaturated fatty acids proved to be good indicators of oxidative processes. The presence (after NaBH 4-reduction) of a high proportion of 11-hydroxyoctadec- cis-9-enoic and 8-hydroxyoctadec- cis-9-enoic acids showed that the degradation of oleic acid involved mainly free radical oxidation processes (70–75% autoxidation and 20–25% photooxidation). We also detected large amounts of degradation products of the oxidation product 9,10-epoxyoctadecanoic acid including diols, methoxyhydrins and chlorohydrins. These oxidative effects were found in all the lipid classes examined. Products included significant amounts of chlorophyll side-chain autooxidation products Z- and E-3,7,11,15-tetramethylhexadec-3-ene-1,2-diols and Z-and E-3,7,11,15-tetramethylhexadec-2-ene-1,4-diols, while phytyldiol was present in relatively low proportions. Δ 5-3β,7-epimeric unsaturated steroidal diols arising from the autooxidation of the Δ 5 double bond of epi-brassicasterol and minor amounts of Δ 4-3β,6-diols were also detected. Long-chain unsaturated ketone (alkenone) content per cell was much higher in the presence of 0.5% CO 2 likely due to carbon storage under these conditions. The proportions of di- and tri-unsaturated alkenones was relatively stable throughout the growth cycle in the absence of additional CO 2, but not when grown with 0.5% CO 2. The detection of characteristic alkenone autoxidation products in cells grown under these latter conditions allowed us to attribute the significant increase in index observed to the involvement of free radical oxidation processes.

Toxic effect of vepesid on morphology and function of the rat liver

Intravenous injection of antitumor drug vepeside in the maximum tolerated dose (MTD) stimulated free radical oxidation processes in rats. Activities of blood aminotransferases and alkaline phosphatase changed. Morphological study of the liver revealed fatty degeneration, hepatocyte necrosis, and inflammatory infiltration.