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Objective: The aim of this study is to evaluate the effect of preeclampsia on the level of lipid peroxidation, activity and expression of both plasma membrane Ca(2+)- and Na(+), K(+)-ATPases in syncytiotrophoblast., Methods: The level of lipid peroxidation was estimated by measuring TBARS. ATPase activities were quantified by a colorimetric method measuring the amount of inorganic phosphate during the assay. Expression of Ca(2+)- and Na(+), K(+)-ATPases in syncytiotrophoblast plasma membranes and term placenta tissue sections was investigated using Western blot and immunohistochemistry, respectively., Results: Our results show a higher level of lipid peroxidation of syncytiotrophoblast plasma membranes from preeclamptic, as compared to uncomplicated pregnant women. Preeclampsia also significantly reduced the activity of Ca(2+)- and Na(+), K(+)-ATPases; however, expression of both ATPases was unaffected., Conclusion: Our findings suggest that the reduction of Ca(2+)- and Na(+), K(+)-ATPase activities during preeclampsia could be at least partially due to an increased level of lipid peroxidation of the syncytiotrophoblast plasma membranes.

Objective: The aim of this study is to summarize the reported evidence on the possible relationship between preeclampsia, placenta, oxidative stress and plasma membrane Ca-ATPase (PMCA) activity, responsible for fine control of intracellular calcium concentration., Methods: Literature search was conducted in MEDLINE/PubMed and several unpublished results from our laboratory were included., Results: Lipid peroxidation in placental and red blood cell plasma membranes during preeclampsia and a concomitant diminution of their PMCA activity are described., Conclusions: Uteroplacental hypoperfusion raises lipid peroxidation by-products in the blood plasma that could alter structure and functionality of the cell membranes of the endothelium and several tissues.

Purpose: Ultraviolet C (UVC) irradiation of aqueous solutions is known to be a good source of reactive oxygen species (ROS). The aim of this study is to examine the effect of increasing doses of UVC irradiation, in the presence and absence of the antioxidant butylated hydroxytoluene (BHT), on human sperm motility and lipid peroxidation of its membranes., Materials and Methods: Human sperm samples were irradiated with UVC light (254 nm) for different periods of time. A computer-assisted semen analysis of sperm motility was carried out after UV irradiation. The percentage of motile sperm (%MOT), progressive motility, straight line velocity (VSL), curvilinear velocity (VCL) and the percentage of linearity (%LIN) were evaluated. The level of lipid peroxidation of sperm membranes was estimated by measurement of the thiobarbituric acid reactive substances (TBARS)., Results: UVC irradiation of human spermatozoa produced a diminution of the sperm motility (%MOT, progressive motility, VSL, VCL, %LIN), viability and, concomitantly, an increase of the level of lipid peroxidation of the sperm membranes. The observed effects of the UVC irradiation were prevented by addition of the antioxidant BHT, indicating that the effects of UVC on the tested sperm parameters are mediated by an important rise in lipid peroxidation of the sperm membrane., Conclusion: Lipid peroxidation of the human sperm plasma membrane leads to a decrease in the sperm motility (%MOT, progressive motility, VSL, VCL, %LIN) and viability. The protective effect of BHT on the UVC-irradiated sperm cells indicates the effects of ROS on sperm function.

Objective: To evaluate the osmotic fragility and level of lipid peroxidation of red blood cells from pregnant women with severe preeclampsia, treated or not with MgSO(4)., Methods: Osmotic fragility and lipid peroxidation of red blood cells was evaluated in 11 normotensive pregnant women and eleven pregnant women with severe preeclampsia., Results: MgSO(4) therapy, either in vivo or in vitro, leads to a reduction of the osmotic fragility and the level of lipid peroxidation of red blood cells from pregnant women with severe preeclampsia., Conclusions: Interaction of MgSO(4) with free radicals, by avoiding an excessive lipid peroxidation of the red blood cell membrane, would protect the membrane structure, avoiding in this way the increase in osmotic fragility.

The increased level of lipid peroxidation of red blood cells during preeclampsia is considered to be responsible for the diminished Ca-ATPase activity in these cells. The level of lipid peroxidation and the Ca-ATPase activity of red blood cells from preeclamptic women, return to their normal values after in vivo and in vitro treatment with MgSO4 for 24 h. In order to evaluate whether or not cell intactness is essential for these changes, we used either intact red blood cells or red cell ghosts from normotensive pregnant women. The intact red blood cells were treated with Fenton's reagent and then incubated with 4 mM MgSO4. The red cells ghosts were irradiated with UV light and afterwards incubated with MgSO4 at 4 degrees C. Lipid peroxidation and Ca-ATPase activity were determined for all the preparations. Both, Fenton's reagent and UV irradiation increased the level of lipid peroxidation and diminished the Ca-ATPase activity of the red cell membranes. Incubation of the cells treated with Fenton's reagent, or the ghosts irradiated with UV, with 4 mM MgSO4, returned Ca-ATPase activity and lipid peroxidation levels to normal values. The presence of MgSO4 blocked the effects in the ghosts of UV irradiation. MgSO4 seems to better protect the red cell membrane against lipid peroxidation than other SO4= and Cl- salts. These results indicate that the changes in the lipid peroxidation of the red cell ghosts and their Ca-ATPase activity are a result of changes to the cell membranes.

Term placental villous fragments from normotensive pregnant women were incubated under hypoxia in order to induce lipid peroxidation of the placental plasma membranes and, consequently, to increase their release of lipid peroxide products into the incubation medium. The homogenates of the villous fragments were assayed for plasma membrane Ca-ATPase (PMCA) activity and TBARS. The incubation medium, after placental hypoxia, was used to incubate intact red blood cells (RBCs) from normotensive pregnant women. Similarly, intact RBCs from normotensive pregnant women were incubated with deproteinized blood plasma from normotensive pregnant women and women with preeclampsia. In all the cases, red cell ghosts were prepared from the incubated cells and assayed for PMCA and TBARS. The incubation of placental villous fragments under hypoxia led to an increase in the TBARS and a significant reduction in the PMCA activity of their homogenates, as compared to those of villous fragments incubated under normoxia. The exposure of intact RBCs from normotensive pregnant women either to the incubation medium of placental hypoxia or to deproteinized blood plasma from women with preeclampsia, caused a rise of the TBARS and a diminution of PMCA activity of the red cell ghosts. Inside-out vesicles were also prepared from intact RBCs incubated with the medium where the placental hypoxia was carried out. These vesicles were assayed for active calcium transport. Pretreatment of RBCs with the incubation medium of placental hypoxia led to a lower active calcium transport as compared to that of inside-out vesicles from RBCs without any preincubation. These results are in agreement with the idea that the RBCs can be peroxidized when passing through a highly oxidized medium, such as the placental intervillous space from women with preeclampsia. The peroxidized RBCs would contribute then to the propagation of lipid peroxidation from the placenta to nearby and far away tissues.

Background: The Ca-ATPase activity of the plasma membranes of several tissues of preeclamptic pregnant women is significantly reduced when compared with the values of normotensive pregnant women. This has been explained considering the raise in the level of lipid peroxidation of the plasma membranes with preeclampsia. In this work we studied the effect of lipid peroxidation of syncytiotrophoblast basal (fetal facing) plasma membranes from normotensive pregnant women, on their level of Ca-ATPase activity., Methods: The syncytiotrophoblast basal (fetal facing) plasma membranes from normotensive pregnant women were isolated and irradiated with ultraviolet (UV) light (254 nm). The membranes were then assayed for Ca-ATPase activity and lipid peroxidation by TBARS., Results: The UV irradiation raises the level of lipid peroxidation of the membranes, producing a concomitant inhibition of their Ca-ATPase activity. Presence of the antioxidant butylated hydroxytoluene during the UV irradiation of the membranes prevents increase in their level of lipid peroxidation and hence the inhibition of their Ca-ATPase activity., Conclusion: These results give a strong support to the hypothesis that the lowered Ca-ATPase activity already described for plasma membranes of several tissues of preeclamptic women is the consequence of the increased level of lipid peroxidation shown by these membranes., (Copyright (c) 2006 S. Karger AG, Basel.)

The effect of the treatment with magnesium sulfate (MgSO(4)) on Ca-ATPase activity and level of lipid peroxidation of red blood cells from preeclamptic pregnant women was examined because it is known that these parameters are affected with preeclampsia. Red cell ghosts from 11 normotensive and 11 preeclamptic pregnant women, before and after treatment with MgSO(4), were assayed for Ca-ATPase activity and level of lipid peroxidation, determined as TBARS or conjugated dienes. It was found that the Ca-ATPase activity is significantly lower and the level of lipid peroxidation is significantly higher in the preeclamptic women with no treatment, as compared to normotensive pregnant women. Both parameters return to normal values after the MgSO(4) therapy. These results can be mimicked by in vitro preincubation with MgSO(4) of intact red blood cells from preeclamptic pregnant women, without any treatment. Our data indicate that MgSO(4) treatment of preeclamptic pregnant women modifies both the Ca-ATPase activity and the level of lipid peroxidation of their red blood cell membranes, reaching values similar to those of normotensive pregnant women. The diminution of the level of lipid peroxidation by MgSO(4), can account for the increase in Ca-ATPase activity.

We previously reported that in preeclampsia Ca-ATPase activity diminishes about 50% in red blood cells, myometrium and syncitiotrophoblast plasma membranes. In this work, we measured the active Ca++ uptake by inside-out vesicles of human red blood cells from preeclamptic and normotensive pregnant women. Active calcium uptake by the vesicles was diminished by 49+/-3% in the preeclamptic women as compared to the gestational controls ( 8.06 +/- 0.11 nmol Ca++/mg protein min, gestational controls; 4.08 +/- 0.1 nmol Ca++/mg protein min, preeclamptics). This lowered calcium uptake correlates well with the lowered Ca-ATPase activity found in the red blood cells ghosts of the preeclamptic women (17.05 +/- 0.96 nmol Pi/mg protein min, gestational controls; 8.85 +/- 0.45 nmol Pi/mg protein min, preeclamptics). The reduced calcium uptake and Ca-ATPase activity of the red cell membranes both appear to be associated with a high level of lipid peroxidation. Thus there is a diminution in the active transport of calcium in the red blood cells of preeclamptic women. If this also occurs in other cell types of the preclamptic women, it could result in an increase in their cytosolic calcium concentration which might be responsible, in part, for some of the symptoms of this disease.

Objective: We determined the calcium activated adenosine triphosphatase (Ca-ATPase) activity and level of lipid peroxidation thiobarbituric acid-reactive substances (TBARS) of red blood cell ghosts in the antepartum and postpartum of normotensive and preeclamptic pregnant women., Methods: Samples of venous blood were obtained by venipuncture of nulliparous normotensive and preeclamptic pregnant women antepartum and two, four, six, and 20 weeks postpartum. The red blood cell ghosts were prepared and assayed for Ca-ATPase activity and TBARS., Main Outcome Measure(s): We expected to find a return to normal values of both Ca-ATPase activity and TBARS level of the red blood cell ghosts, modified in the preeclamptic pregnant women, during their puerperium., Results: The Ca-ATPase activity of red cell ghosts from preeclamptic women, antepartum, is lower than that of normotensive pregnant women. The ATPase activity returns to normal values during the first six weeks of postpartum. The level of TBARS of red cell ghosts from preeclamptic women follows a pattern that is inversely proportional to the one of the Ca-ATPase activity., Conclusions: Preeclampsia produces a significant diminution of the Ca-ATPase activity and an increase in the levels of TBARS in the erythrocytes. As soon as all the symptoms of preeclampsia disappear in the postpartum, both Ca-ATPase activity and TBARS return to normal values.

Objective: We evaluated the effect of lipid peroxidation on the calcium adenosine triphosphatase activity of red blood cell ghosts from normotensive pregnant women and compared it with the adenosine triphosphatase activity and lipid peroxidation in preeclampsia., Study Design: Ten nulliparous normotensive and 10 nulliparous preeclamptic pregnant women (38 to 39 weeks of gestation) were used as blood donors. Preeclampsia was diagnosed on the basis of blood pressure (>140/90 mm Hg) and proteinuria (>0.5 gm of urinary protein per day). Red blood cell ghosts were prepared for both groups and used for calcium adenosine triphosphatase activity and lipid peroxidation determinations. Control ghosts (normotensive) were irradiated with ultraviolet light for different lengths of time., Results: Calcium adenosine triphosphatase activity of red blood cell ghosts from normotensive women is sensitive to lipid peroxidation. The lipid peroxidation of red blood cell ghosts from preeclamptic women is higher than that from normotensive women., Conclusion: The diminution of the calcium adenosine triphosphatase activity with preeclampsia could be explained by the sensitivity of this adenosine triphosphatase to lipid peroxidation.

In the present paper we summarize the theoretical aspects of the process of lipid peroxidation of the plasma membranes from cells of animal tissues. Also, we review the activity of plasma membrane ATPases, i.e., The Na,K-, Na- and Ca-ATPases, and how this modulation could play a role in some diseases.

The present work evaluates the effect of lipid peroxidation on the ouabain-insensitive Na-ATPase of basolateral plasma membranes from rat kidney proximal tubular cells as an indirect way to study the lipid dependence of this enzyme. An inverse relationship between lipid peroxidation and Na-ATPase activity was found. This effect was due neither to a change in the optimal Km of the system for Na+ nor for the substrate Mg:ATP, nor the optimal pH value of the medium. The optimal temperature value, however, was shifted toward a higher value. There was also an increase of the apparent energy of activation in the region of temperatures above the transition point (20 degrees C) with increase in lipid peroxidation. Peroxidized membranes incubated with phosphatidylcholine from soybean restored their Na-ATPase activity. On the other hand, the Na-ATPase activity was sensitive to oleoly lysophosphatidylcholine. These results suggest that lipid peroxidation might be affecting the Na-ATPase activity through either an increase of peroxidized phospholipids, which might change the membrane fluidity of the lipid microenvironment of the ATPase molecules, or through a direct effect of lysophospholipids released during the lipid peroxidation.

Objective: To evaluate the osmotic fragility of red blood cells and the level of lipid peroxidation, the Ca(2+)-ATPase activity of red cell ghosts and placental homogenates from salt-loaded pregnant rats.Methods: Salt-loaded pregnant rats received 1.8% NaCl solution ad libitum as a beverage for seven days, starting on 15th day of pregnancy. Then, it was evaluated the level of lipid peroxidation and the Ca(2+)-ATPase activity of placental homogenates and red blood cell ghosts from control and experimental rats. Furthermore, the osmotic fragility of the red blood cells was evaluated by measuring the lysis of these cells when incubated with a NaCl solution with different osmolarities.Results: It was found that placental homogenates and red blood cell ghosts from experimental pregnant rats showed an increased level of lipid peroxidation and a lowered Ca(2+)-ATPase activity, as compared to control pregnant rats. They also presented an increased osmotic fragility of their red blood cells.Conclusions: Salt-loaded pregnant rats showed, similar to preeclamptic women, an increased level of lipid peroxidation and a lowered Ca(2+)-ATPase activity in placental and red blood cells membranes, as well as an increased osmotic fragility of the red blood cells. [ABSTRACT FROM AUTHOR]

C11‐BODIPY581/591 is a fluorescent probe that has been successfully used to evaluate lipid peroxidation in different species, but it has not been completely studied in the dog. Thus, the aim of the present study was to assess lipid peroxidation of dog spermatozoa using C11‐BODIPY581/591 and compare different positive controls of the technique. Twenty‐four ejaculates were collected from 8 adult male dogs. Routine seminal characteristics were evaluated in raw semen. Lipid peroxidation evaluation was performed as described in other species. Samples were divided in three aliquots, exposed to UV radiation, incubated with hydrogen peroxide or left without treatment (control). Lipid peroxidation was significantly greater only in UV‐exposed samples than in the control ones (91 ± 6% vs. 8.3 ± 3.5%, p ˂.01). In conclusion, C11‐BODIPY581/591 is useful to evaluate lipid peroxidation of dog spermatozoa and UV radiation is a good promoter of membrane oxidation, so irradiated samples can be used as a positive control of this technique. [ABSTRACT FROM AUTHOR]

Inflammation in the male genitourinary tract has been associated with the release of pro-inflammatory cytokines such as interferon-gamma (IFN-γ) and elevated reactive oxygen species, which affects spermatozoa capacitation, motility, and the acrosome reaction, along with functions regulated by the concentration of cytoplasmic Ca2+ ([Ca2+]cyto). Though Ca2+ signaling is of particular significance in sperm, the effect of IFN-γ intracellular calcium on these cells is still unknown. The present study evaluated the effect of IFN-γ on the [Ca2+]cyto and Ca2+ permeability on human sperm. A cell suspension loaded with fura-2 was incubated with or without IFN-γ (from 0 to 2000 pg/ml) for 0, 30, 60, and 120 minutes, and the [Ca2+]cyto was measured. The permeability to Ca2+ was evaluated by the change of the intracellular concentration following an extracellular Ca2+ pulse. IFN-γ at low concentrations (≤500 pg/ml) did not affect the [Ca2+]cyto and Ca2+ permeability of sperm. At a high concentration (2000 pg/ml), IFN-γ did not alter the [Ca2+]cyto, but significantly decreased the magnitude and velocity of Ca2+ entry into the cell. This effect was dependent on incubation time and IFN-γ concentration. This alteration induced by IFN-γ was prevented by the simultaneous incubation of sperm with the antioxidant butylhydroxytoluene (BHT). In conclusion, in vitro, IFN-γ modifies Ca2+ sperm membrane permeability, probably via lipid peroxidation. IFN-γ in high concentration, as observed in inflammation/infection, can affect [Ca2+]cyto regulation and alter sperm fertilizing capacity. [ABSTRACT FROM AUTHOR]

Problem Inflammation and genital infections promote the increase in leukocytes, pro-inflammatory cytokines, and oxygen reactive species, impairing sperm functions such as motility, capacitation, and acrosome reaction. All these functions are primarily regulated by cytoplasmic concentration of Ca2+ ([ Ca2+]cyto). This study evaluated the effect of tumor necrosis factor ( TNF)-α on the [ Ca2+]cyto and its regulation in human sperm. Method of study Sperm loaded with fura-2 were incubated with or without TNF- α (0-500 pg/mL) from 0 to 120 min. After incubation, the basal [ Ca2+]cyto and membrane permeability to Ca2+ were evaluated by spectrofluorometry, before and after Ca2+ addition to the extracellular medium. Results Without TNF-α, the addition of Ca2+ promotes an transitory increase in [ Ca2+]cyto in the spermatozoa, that returns in a few minutes to a basal level, indicating calcium regulation activation. TNF-α decreases the Ca2+ permeation and increases the basal level of [ Ca2+]cyto after a Ca2+ pulse ( P < 0.04); affecting calcium regulation in a way that is time and concentration dependent. TNF-α effect was partially prevented by the addition of an antioxidant (butylated hydroxytoluene) ( P < 0.03). Conclusion Tumor necrosis factor-α decreases membrane permeability to Ca2+ and affects Ca2+ regulation in sperm cells in vitro, probably via lipid peroxidation, which may explain the decrease in sperm fertilizing capacity during inflammatory and infectious processes. [ABSTRACT FROM AUTHOR]

Intrauterine ischemia-reperfusion (I/R) injury in fetus occurs with multifactorial pathogenesis and results with multiorgan injury including skin. Magnesium has widespread use in obstetric practice. Inn addition to magnesium's tocolytic and neuroprotective properties, it also has free radical reducing effects. The aim of the present study was to demonstrate whether magnesium sulfate could have protective effect on fetal rat skin in intrauterine ischemia-reperfusion (I/R) injury. Fetal skin ischemia was induced by clamping the utero-ovarian arteries bilaterally for 30 min, and reperfusion was achieved by removing the clamps for 60 min in 19-day pregnant rats. Magnesium Sulfate (MgSO) was given to pregnant rats 20 min before I/R injury at the dose of 600 mg/kg in magnesium treatment group. No ischemia reperfusion was applied to control and sham-operated groups. Lipid peroxidation from the skin tissues was determined as thiobarbituric acid reactive substances (TBARS). Myeloperoxidase (MPO) activity was determined for neutrophil activation. The results showed that the levels of TBARS and MPO increased significantly in the fetal rat skin after I/R injury compared to control group. Levels of TBARS and MPO were significantly lower than those of I/R group in Magnesium-treated group. In conclusion, intrauterine ischemia-reperfusion may produce considerable fetal skin injury. Increased TBARS and MPO activity can be inhibited by magnesium treatment. This suggests that magnesium treatment may have protective effect on fetal rat skin in intrauterine I/R injury. [ABSTRACT FROM AUTHOR]

The reaction products derived from lipid peroxidation, as well as superoxide dismutase and catalase enzyme activities were measured in tissues of catfish (Clarias gariepinus) exposed to oil in water dispersions of 0%, 0.5%, 1.0% and 1.5% for 0, 7, 14, 21 and 28 days. Lipid peroxidation significantly (P<0.05) increased in various tissues relative to control values after 14, 21, and 28 days of exposure to 1.0% and 1.5% oil in water dispersions. Catalase and superoxide dismutase activities decreased after 7 days of exposure but significantly (P<0.05) increased after 14, 21 and 28 days of exposure to 1.0% and 1.5% oil in water dispersions. The elevated levels of lipid peroxidation, superoxide dismutase and catalase activities in all tissues examined inC. gariepinuscould be a reflection of oxidative stress on the fish. These observations seem to implicate that petroleum hydrocarbons act as a mediator in free radical generation. The increase in catalase and superoxide dismutase activities in these tissues could be an adaptive response to protect the fish from petroleum-hydrocarbon-induced free radical toxicity. [ABSTRACT FROM AUTHOR]

Object. The aim of this study was to evaluate the lipid and protein oxidation and antioxidant function in preeclampsia patients and in normotensive pregnant women, as well as, to assess an association with the severity of the disease. Method. The study was carried out in 30 patients with mild preeclampsia, 30 with severe preeclampsia, and in 50 normotensive pregnant women during the third trimester of pregnancy. Lipid peroxides in serum, placental and decidual tissues and serum protein carbonyls and some of the antioxidants were measured by spectrophotometric methods. One-way analysis of variance, chi-square test and Pearson correlation test were used for the statistical analyses. Logistic regression procedures were used to calculate odds ratios (OR). Results. Lipid peroxides in serum, placenta and decidua basalis and protein carbonyls in serum were significantly increased, and vitamin E and total carotene levels in serum were significantly decreased especially in women with severe preeclampsia compared with mild preeclampsia and controls. A significant correlation was detected between diastolic blood pressure and lipid peroxides in serum, placental and decidual tissues and serum protein carbonyls. Furthermore, there was significant correlation between antioxidant vitamins and lipid and protein oxidation products in severe preeclamptic patients. Also, logistic regression analysis showed that changes in serum, placental and decidual lipid peroxides and serum protein carbonyls, vitamin E and total carotene concentrations were significantly associated with preeclampsia. Conclusion. Our findings suggest that lipid and protein oxidation may be an important factor in the pathogenesis of preeclampsia. Since antioxidant vitamins are significantly decreased in both severe and mild preeclamptic pregnants, early supplementation with antioxidants may be beneficial in preeclamptic patients. [ABSTRACT FROM AUTHOR]