Parameters Of Oxidative Metabolism Research Articles

Immune System Behavior during Herpesvirus Infection in Childhood

Background: Persistently infected cells by herpesvirus (HSV, CMV, EBV) and their dysfunction are associated with different disorders. The immune and endocrine systems are involved in pathogenesis of herpesvirus infection. Changes of IFN-γ, IL-4, DHEAS and cortisol level are a part of the regulatory mechanisms of the immune and endocrine system responses in persistent herpesvirus infection. Objectives: The aim of this study was to identify immunoregulatory mechanisms (clinical manifestations, cytokines level-IFN-γ, et IL-4, hormones level-DHEAS, cortisol, parameters of oxidative metabolism, enzymes of cell injury) and their consequences concerning clinical disease expression (low level of hemoglobin (Hb), leucocitopenia, high level of monocytes, hyper gamaglobulins, low level of NBT-test). Study design: 40 children (1-16 years old) with herpesvirus infection were analyzed. In patients routine laboratory investigations were performed: white blood cells count, lactate dehydrogenize-LDH, creatinin-kinaza- CPK, oxidative metabolism of the blood phagocytes, the ability of phagocytes nitro-blue tetrazolium-NBT reduction and immunoglobulin serum level. Serum levels of IFN-γ, IL-4, DHEAS and cortisol were measured by ELISA test. Normal healthy controls had negative ELISA tests for CMV, HSV and EBV Results: The high level of LDH, CPK, low ability of NBT reduction and hypergammaglobulins were detected. The increases of IFN-γ, IL-4 level, as well as, the decrease of DHEAS and cortisol level were present. The patients with the high level of IFN-γ, had the high level of LDH, CPK, GOT, GPT, the low level of Hb, leucocitopenia and monocytes. Conclusions: Two groups of patients were presented. First with the high level of IFN-γ (70%) and second with the high level of IL-4.The patients in the first group, with the high level of IFN-γ, had anemia, respiratory infections, BHR, labial HSV, stomatitis aphtosa. Vasculitis, anginae recidivans, was clinical manifestation characteristics for in patients in the second group with the high level of IL-4. The high level of LDH, CPK, the low ability of NBT reduction and hypergammaglobulins were detected. The patients with the high levels of IFN-γ, had the high level of LDH, CPK, GOT, GPT, the low level of Hb, leukopenia and monocytosis. The decreased level of DHEAS (50%) and the normal level of cortisol (76%) were present. The low levels of DHEAS followed the IgG high values while leucopenia (78%), was followed by high values of DHEAS. The patients with normal cortisol values had the significant monocytosis (80%) while patients with the low cortisol level had the high IgG (85%) level.

Ethylmalonic acid impairs brain mitochondrial succinate and malate transport

Tissue accumulation and high urinary excretion of ethylmalonic acid (EMA) occur in ethylmalonic encephalopathy (EE) and short chain acyl-CoA dehydrogenase deficiency (SCADD). Although these autosomal recessive disorders are clinically characterized by neurological abnormalities, the mechanisms underlying the brain damage are poorly known. Considering that little is known about the neurotoxicity of EMA and that hyperlacticacidemia occurs in EE and SCADD, we evaluated the effects of this metabolite on important parameters of oxidative metabolism in isolated rat brain mitochondria. EMA inhibited either ADP-stimulated or uncoupled mitochondrial respiration supported by succinate and malate, but not by glutamate plus malate. In addition, EMA mildly stimulated oxygen consumption by succinate-respiring mitochondria in resting state. Methylmalonic acid (MMA), malonic acid (MA) and butylmalonic acid (BtMA) had a similar effect on ADP-stimulated or uncoupled respiration. Furthermore, EMA-, MMA- and BtMA-induced inhibitory effects on succinate oxidation were significantly minimized by nonselective permeabilization of the mitochondrial membranes by alamethicin, whereas MA inhibitory effect was not altered. In addition, MA was the only tested compound that reduced succinate dehydrogenase activity. We also observed that EMA markedly inhibited succinate and malate transport through the mitochondrial dicarboxylate carrier. Mitochondrial membrane potential was also reduced by EMA and MA, but not by MMA, using succinate as electron donor, whereas none of these compounds was able to alter the membrane potential using glutamate plus malate as electron donors. Taken together, our results strongly indicate that EMA impairs succinate and malate uptake through the mitochondrial dicarboxylate carrier.

Effects of alcohol-free beer on lipid profile and parameters of oxidative stress and inflammation in elderly women

Objective We assessed the influence of alcohol-free beer on factors implicated in atherosclerosis, such as lipid profile, oxidative stress parameters, and proinflammatory cytokines, in postmenopausal women, a population particularly at risk for atherosclerotic disease. Methods The study was carried out in 29 nuns, 58 to 73 y old, who live in a convent with a disciplined, regular, and homogeneous lifestyle. The nuns maintained their habits and diet routine, but their meals were supplemented with 500 mL/d of alcohol-free beer (0.0%) divided into two doses over a 45-d period. Lipid profile, inflammatory markers such as C-reactive protein, interleukins 1 and 6, and tumor necrosis factor-α, and parameters of oxidative metabolism were determined before and after the study period. Results There were no differences in the levels of C-reactive protein and proinflammatory cytokines after diet supplementation. The antibody titers to oxidized low-density lipoprotein were significant lower ( P < 0.05), and thiobarbituric acid–reactive substances (−18%, P < 0.001) and plasma carbonyl group content (−21%, P < 0.001) were decreased when compared with initial values. Increases in α-tocopherol levels (+9%, P < 0.05) and erythrocytic glutathione levels (+29%, P < 0.001) were also noted. With respect to lipid profile, only subjects with cholesterol levels higher than 240 mg/dL showed lower levels after supplementation. Conclusion Consumption of non-alcoholic beer produces a decrease in oxidative stress that can have a beneficial impact on cardiovascular risk; however, the circulating concentrations of inflammatory mediators involved in its pathophysiology remained unchanged.

Failure to confirm ferritin and caeruloplasmin as risk factors for the angiographic extent of coronary arteriosclerosis

It has been suggested that iron overload, as assessed by increased serum ferritin concentration, may be a risk factor for coronary artery disease (CAD). Recent studies have reported conflicting data on the role of ferritin and other parameters of oxidative metabolism in CAD. The aim of this study was to assess the relation between the extent of CAD and parameters of oxidation. We studied 275 patients (208 men aged 55.1 +/- 9.6 years and 67 women aged 54.6 +/- 10.0 years) who underwent coronary angiography or percutaneous transluminal coronary angioplasty for the first time. The parameters assessed were: iron, ferritin, transferrin, copper, caeruloplasmin and lipid. Cinefilms were assessed by the use of three scores: (1) Vessel score: 0-3 points; 1 point for each of the three main coronary arteries with a stenosis >70%. (2) Stenosis score: 0-32 points; the coronary artery tree was divided into eight segments that were scored 1-4 points per segment with respect to the maximal degree of stenosis. (3) Extent score: 0-100 points; extent of diffuse coronary lesions in each segment in relation to the length of the vessel. Multiple regression analyses were used to evaluate the results. Total cholesterol and low-density lipoprotein cholesterol (P < 0.001) in women, low-density lipoprotein cholesterol (P < 0.05) in men, and patient age showed a significant correlation with all three scores, but none of the parameters of oxidative metabolism (iron, transferrin, ferritin, copper, caeruloplasmin) correlated significantly with any of the three scores. This study demonstrated a correlation between lipoproteins and the angiographic extent of CAD, but did not confirm a role for serum ferritin and other oxidative parameters as risk factors for the extent of CAD.

Failure to confirm ferritin and caeruloplasmin as risk factors for the angiographic extent of coronary arteriosclerosis

Background It has been suggested that iron overload, as assessed by increased serum ferritin concentration, may be a risk factor for coronary artery disease (CAD). Recent studies have reported conflicting data on the role of ferritin and other parameters of oxidative metabolism in CAD. Objective The aim of this study was to assess the relation between the extent of CAD and parameters of oxidation. Methods We studied 275 patients (208 men aged 55.1 ± 9.6 years and 67 women aged 54.6 ± 10.0 years) who underwent coronary angiography or percutaneous transluminal coronary angioplasty for the first time. The parameters assessed were: iron, ferritin, transferrin, copper, caeruloplasmin and lipid. Cinefilms were assessed by the use of three scores: (1) Vessel score: 0–3 points; 1 point for each of the three main coronary arteries with a stenosis >70%. (2) Stenosis score: 0–32 points; the coronary artery tree was divided into eight segments that were scored 1–4 points per segment with respect to the maximal degree of stenosis. (3) Extent score: 0–100 points; extent of diffuse coronary lesions in each segment in relation to the length of the vessel. Multiple regression analyses were used to evaluate the results. Results Total cholesterol and low-density lipoprotein cholesterol (P < 0.001) in women, low-density lipoprotein cholesterol (P < 0.05) in men, and patient age showed a significant correlation with all three scores, but none of the parameters of oxidative metabolism (iron, transferrin, ferritin, copper, caeruloplasmin) correlated significantly with any of the three scores. Conclusion This study demonstrated a correlation between lipoproteins and the angiographic extent of CAD, but did not confirm a role for serum ferritin and other oxidative parameters as risk factors for the extent of CAD. Coronary Artery Dis 9:119-124 ©1988 Lippincott-Raven Publishers.

Effect of cytochrome C and its derivatives on the circulation and oxidative metabolism of the ischemized brain

The effects of animal and biotechnological cytochrome C and its hemtetradecapeptide in a heme-isomolar dose on the cerebral bloodflow, oxygen and glucose consumption, and pH of the ischemized brain were studied in cat experiments. Cytochrome of both types and hemtetradecapeptide increased the consumption of oxygen and glucose by ischemized brain tissue and somewhat reduced the development of acidosis. The shifts of oxidative metabolism parameters of the ischemized brain correlated with inhibition of the development of postischemic hypoperfusion of the brain.

Oxidative metabolism of neutrophilic polymorphonuclear leukocytes in experimental massive pulmonary embolism

Oxidative metabolism of neutrophilic polymorphonuclear leukocytes circulating in the blood was studied by chemiluminescent analysis and the nitroblue tetrazolium reduction test. Pronounced activation of oxidative metabolism of polymorphonuclear leukocytes was observed by the third and sixth hours of massive embolism of the pulmonary arteries. Comparison of the examined parameters of oxidative metabolism of leukocytes isolated simultaneously from venous and arterial blood indicates a delay of the most active cell fraction in pulmonary vessels during massive embolism. The transfer of functionally active leukocytes from the circulating to the marginal pool of the lungs suggests their participation in damaging the pulmonary microvascular endothelium and in increasing its permeability.

Effects ofβ‐Carotene repletion onβ‐carotene absorption, lipid peroxidation, and neutrophil superoxide formation in young men

The chemopreventive effects of beta-carotene are usually attributed to its antioxidant properties. To determine the effects of beta-carotene supplementation on different parameters of oxidative metabolism, 15 normal young male subjects (18-30 yrs) were placed on a carotenoid-free liquid diet for two weeks prior to entry into the study. Blood was then measured for five carotenoids, retinol, retinyl palmitate, retinol-binding protein, alpha-tocopherol, vitamin C, zinc, lipid peroxides, and neutrophil superoxide production. Absorption tests were performed with 15 mg of beta-carotene to determine absorption curves for each subject. Subjects were then divided into two groups and given either 15 (n = 7) or 120 (n = 8) mg of beta-carotene daily for four weeks along with the same carotenoid-free liquid diet. The absorption test and the blood measurements were repeated. After repletion with beta-carotene, serum lipid peroxide levels decreased in both groups (p less than 0.05), but no other changes were noted in either the neutrophil superoxide production or in the levels of any of the vitamins measured. In contrast to vitamin E, the superoxide scavenging ability of beta-carotene apparently does not contribute to its effects in lowering serum lipid peroxide levels.

Influence of Lactate Accumulation on Calcium Content of Ischemic and Postischemic Brain

In this study, the cerebral hemisphere content of calcium as well as selected parameters of oxidative metabolism and electrophysiological function were assessed in normoglycemic and hyperglycemic rats that were exposed to ischemia produced by electrocautery of the vertebral arteries and reversible occlusion of the carotid arteries. In hyperglycemic animals, 0.5 h of ischemia was associated with large accumulations of lactate (27 mmol/kg), whereas normoglycemic animals showed lesser lactate accumulation (17 mmol/kg). At this sampling time (0.5 h of ischemia), both groups of ischemic animals showed tissue calcium contents that were unchanged from preischemic control levels. In normoglycemic animals, release of the carotid clamps and recirculation for 1.5-24 h was associated with normalization of lactate, ATP and phosphocreatine, clinical behavior, and EEG. During this 24 h of recirculation, cerebral calcium levels showed no changes. Hyperglycemic ischemic animals recirculated for 1.5-24 h showed a persistent lactic acidosis, depressed ATP and phosphocreatine, gross EEG abnormalities, seizures, and a high mortality rate. Again, during this 24 h period, cerebral calcium content showed no changes from preischemic control or from the matched saline-treated group. These data suggest that significant accumulation of calcium in brain tissue is not an early event in ischemic-hyperglycemic brain damage, and thus does not provide support for a role of calcium in the production of this form of ischemic damage.

Oxidative metabolism of cultured human skeletal muscle cells in comparison with biopsy material

Human muscle cell cultures were examined for capacities to oxidize several substrates and for activities of some enzymes related to intermediate metabolism. The results indicate that mitochondrial activities attained appreciable degrees of maturity. The specific activity of creatine kinase increased during myoblast fusion. In contrast, parameters of oxidative metabolism (palmitate and pyruvate oxidation, and cytochrome c oxidase and citrate synthase) did not significantly change throughout myogenesis and thereafter. In differentiated cells (myotubes) the oxidation capacties were pyruvate > 2-oxoglutarate > malate ( + acetylcarnitine) > malate (+ pyruvate), as in muscle biopsies. With regard to protein the cultured human cells showed higher activities than the original biopsies (= 100%) with respect to citrate synthase (179%), but lower values for cytochrome c oxidase (50%) and creatine kinase (7%). Palmitate oxidation capacicities were the same in both systems. The presence of antimycin and rotenon inhibited to a comparable extent the palmitate oxidation in cultured muscle and biopsies.

Influence of lactate accumulation on Na +,K +-ATPase activity of ischemic and post-ischemic brain

In this study the cerebral Na +,K +-ATPase activity as well as selected parameters of oxidative metabolism and electrophysiological function were assessed in normoglycemic and hyperglycemic rats which were exposed to ischemia produced by eletrocautery of the vertebral arteries and reversible occlusion of the carotid arteries. In hyperglycemic animals 0.5 h of ischemia was associated with massive accumulation of lactate (34 μmol·g −1) and enhanced Na +,K +-ATPase activity (116% control), whereas normoglycemic animals showed more moderate lactate accumulation (17 μmol·g −1) and normal Na +,K +-ATPase activity (102% control). In normoglycemic animals release of the carotid clamps and recirculation for 0.5-1.5 h was associated with a normalization of the lactate levels and a decrease in Na +,K +-ATPase activity (68–72% control). Restituted hyperglycemic animals showed metabolic changes which seemed related to the blood pressure, with hypotensive hyperglycemic animals showing continuing massive lactacidosis (30–35 μmol·g −) and enhanced Na +,K +-ATPase activity (108–110% control), whereas normotensive hyperglycemic animals showed progressive decreases in lactate level (14–20 μmol·g −1) and normal or mildly suppressed Na +,K +-ATPase activity (88–97% control). These patterns of change suggest that the reperfusion of the post-ischemic hyperglycemic-hyperlactacidotic brain was inadequate or non-homogenous.

Skeletal muscle fibers in suspension: A new approach to the study of oxidative and glycolytic metabolism in differentiated muscle

1. 1. A preparation of suspended fibers from m. flexor digitorum brevis of the rat was characterized with respect to morphological features, and its relevance for the study of muscular metabolism investigated. 2. 2. The activities of oxidative (palmitate and pyruvate oxidation) and glycolytic (lactate formation) pathways were enhanced in myofiber suspensions when compared to intact whole muscle. 3. 3. The rate of glycolysis was stimulated about two-fold by insulin in both the myofiber suspensions and intact muscle. 4. 4. Parameters of oxidative metabolism responded similarly to metabolic effectors in the myofiber suspensions and in intact muscle. 5. 5. It is concluded that the myofiber suspensions have distinct advantages over intact muscle for biochemical and pharmacological studies.

Cerebral Na+,K+-ATPase activity during exposure to and recovery from acute ischemia.

This study documents the Na+,K+-ATPase activity as well as selected parameters of oxidative metabolism and electrophysiological function in rat brain exposed to ischemia produced by electrocautery of the vertebral arteries and reversible occlusion of the carotid arteries. During a 0.5-h ischemic exposure in which the electroencephalograph (EEG) was abolished and energy metabolism severly compromised the Na+,K+-ATPase showed a capability for enhanced activity (120-140% of control). On recirculation, the Na+,K+-ATPase activity showed a phasic pattern, which was characterized by normal values at 0.25-2 h, increased values (115-125% of control) at 3-24 h, and, finally, normal values at 72 h of recirculation, respectively. The maintenance of Na+,K+-ATPase integrity was correlated with a gradual return of EEG activity and virtually complete restitution of the cerebral energy state during the 72 h of recirculation. Measurements of thiobarbituric acid reactive material and water soluble antioxidant during ischemia and recirculation gave no evidence of the presence of significant free radical lipid peroxidation in this model. It is concluded that Na+,K+-ATPase and its associated membrane lipids are not irreversibly damaged by ischemia in which the tissue lactacidosis is limited to less than 20 mumol g-1.

Oxidative Metabolism of the Human Eosinophil

We have compared the oxidative metabolism of human eosinophils (80%-90% purity) to that of neutrophils. Hexose monophosphate (HMP) shunt activity of eosinophils was higher than that of neutrophils under either resting or phagocytizing conditions. Eosinophil HMP shunt activity also was stimulated by phorbol myristate acetate, a membrane-active agent. Eosinophils showed a marked incorporation of 125I into trichloroacetic acid-insoluble material under resting conditions, which increased markedly during phagocytosis. Eosinophils likewise showed a greater reduction of nitroblue tetrazolium dye during phagocytosis than did neutrophils. Measurement of other parameters of oxidative metabolism indicated that eosinophils generated superoxide anion following phagocytosis and also elicited a burst of chemiluminescence similar to that observed during phagocytosis by neutrophils. Measurement of NADPH oxidase activity demonstrated that this enzyme was 3-6 times more active in fractions isolated from eosinophils than in corresponding fractions isolated from neutrophils; this was observed over a range of substrate concentrations. The eosinophil enzyme sedimented differently than the neutrophil enzyme with differential centrifugation; neither showed sedimentation characteristics of peroxidase. These data indicate that eosinophils possess a similar, although in some ways more potent, oxidative burst than neutrophils and are consistent with a role for NADPH oxidase in the initiation of that burst.

Oxidative metabolism of the human eosinophil

We have compared the oxidative metabolism of human eosinophils (80%-90% purity) to that of neutrophils. Hexose monophosphate (HMP) shunt activity of eosinophils was higher than that of neutrophils under either resting or phagocytizing conditions. Eosinophil HMP shunt activity also was stimulated by phorbol myristate acetate, a membrane- active agent. Eosinophils showed a marked incorporation of 125I into trichloroacetic acid-insoluble material under resting conditions, which increased markedly during phagocytosis. Eosinophils likewise showed a greater reduction of nitroblue tetrazolium dye during phagocytosis than did neutrophils. Measurement of other parameters of oxidative metabolism indicated that eosinophils generated superoxide anion following phagocytosis and also elicited a burst of chemiluminescence similar to that observed during phagocytosis by neutrophils. Measurement of NADPH oxidase activity demonstrated that this enzyme was 3–6 times more active in fractions isolated from eosinophils than in corresponding fractions isolated from neutrophils; this was observed over a range of substrate concentrations. The eosinophil enzyme sedimented differently than the neutrophil enzyme with differential centrifugation; neither showed sedimentation characteristics of peroxidase. These data indicate that eosinophils possess a similar, although in some ways more potent, oxidative burst than neutrophils and are consistent with a role for NADPH oxidase in the initiation of that burst.