Anna Ida Fiaschi

Correlation between cardiac oxidative stress and myocardial pathology due to acute and chronic norepinephrine administration in rats

Background: To investigate the cardiotoxic role of reactive oxygen species (ROS) and of products derived from catecholamines auto‐oxidation, we studied: (1) the response of antioxidant cardiac cellular defence systems to oxidative stress induced by norepinephrine (NE) administration, (2) the effect of NE administration on cardiac β1‐adrenergic receptors by means of receptor binding assay, (3) the cellular morphological alterations related to the biologically cross‐talk between the NE administration and cytokines [tumor necrosis factor‐alpha (TNF‐α), monocyte chemotactic protein‐1 (MCP‐1), interleukins IL6, IL8, IL10]Methods and Results: A total of 195 male rats was used in the experiment. All animals underwent electrocardiogram (EKG) before being sacrificed. The results obtained show that NE administration influences the antioxidant cellular defence system significantly increasing glutathione peroxidase (GPx) activity, glutathione reductase (GR) and superoxide dismutase (SOD). The oxidized glutathione (GSH/GSSG) ratio significantly decreases and malondialdehyde (MDA) levels increase showing a state of lipoperoxidation of cardiac tissue. We describe a significant apoptotic process randomly sparse in the damaged myocardium and the effect of ROS on the NE‐mediated TNF‐α, MCP‐1, and IL6, IL8, IL10 production. Conclusions: Our results support the hypothesis that catecholamines may induce oxidative damage through reactive intermediates resulting from their auto‐oxidation, irrespective of their interaction with adrenergic receptors, thus representing an important factor in the pathogenesis of catecholamines‐induced cardiotoxicity. The rise of the cardioinhibitory cytokines may be interpreted as the adaptive response of jeopardized myocardium with respect to the cardiac dysfunction resulting from NE injection.

Intracoronary serotonin release after high-pressure coronary stenting

It is known that platelet-derived serotonin at the site of coronary angioplasty induces an increase in coronary tone and plays a role in vasoconstriction after balloon angioplasty. The goal of the present investigation was to compare local release of serotonin with changes in coronary tone after coronary stenting and coronary angioplasty. Twenty patients with significant stenosis (> or =50% diameter narrowing) of the left anterior descending coronary artery were referred to traditional coronary angioplasty (10 patients; group 1) or high-pressure coronary stenting (10 patients; group 2). An additional 16 patients with similar angiographic characteristics were referred to the coronary angioplasty group (8 patients; group 1a) or stenting group (8 patients; group 2a) after pretreatment with ketanserin. Serotonin plasma levels in coronary sinus and coronary cross-sectional area distal to the site of dilatation were measured before and after bath revascularization procedures. In groups 1 and 1a, plasma serotonin levels in coronary sinus increased from basal values of 3.2+/-0.8 and 3.2+/-0.5 ng/ml to 29.5+/-13 and 25.6+/-9 ng/ml after ballooning (p <0.001 vs baseline). In groups 2 and 2a, plasma serotonin levels in coronary sinus increased from basal values of 3.5+/-0.3 and 3.5+/-0.7 ng/ml to 114.6+/-34 and 113+/-29 ng/ml after stenting (p <0.001 vs baseline and vs postangioplasty values in groups 1 and 1a). Coronary cross-sectional area distal to the site of dilatation significantly decreased after angioplasty in group 1 (from 4.33+/-0.4 to 3.32+/-0.3 mm2; p <0.001), and after stenting in group 2 (from 4.27+/-0.3 to 2.86+/-0.2 mm2; p <0.001 vs baseline, and p <0.02 vs values after coronary angioplasty in group 1). Pretreatment with ketanserin significantly reduced distal coronary vasoconstriction after angioplasty and stenting. It is concluded that the higher local serotonin release after coronary stenting may explain the more marked coronary constriction observed after prosthesis deployment with respect to traditional coronary angioplasty. Ketanserin is able to significantly attenuate the increase in distal coronary tone induced by both revascularization procedures.

Markers of cardiac oxidative stress and altered morphology after intraperitoneal cocaine injection in a rat model

Abstract This study was designed to assess the parameters of myocardial oxidative stress and related cardiac morphological changes following intraperitoneal cocaine exposure in rats. The cardiac levels of reduced glutathione(GSH), oxidised glutathione(GSSG), ascorbic acid (AA), and the production of malondialdehyde (MDA) were measured, as well as the variations of activity in the enzyme systems involved in cell antioxidant defence, glutathione peroxidase (GSH-Px), glutathione reductase (GR) and superoxide dismutase (SOD). After chronic cocaine administration for 30 days GSH was significantly depleted in the heart from 30 min (P < 0.001) to 24 h (P < 0.001) after exposure, and GSSG was increased for a similar time (P < 0.05 at 30 min and P < 0.01 at 24 h). SOD increased during the first hour (P < 0.001), GR and GSH-Px both increased from 30 min to 24 h, and these increases were statistically significant (P < 0.01 and P < 0.001 at 30 min and P < 0.01 and P < 0.001 at 24 h, respectively). The AA levels increased after 1 h (P < 0.01), remaining significantly so for 24 h (P < 0.001) and MDA increased from 30 min to 24 h, all values being highly significant (P < 0.001). The body weight was significantly (P < 0.001) reduced in both cocaine groups (40 mg/kg × 30 days and 40 mg/kg × 10 days + 60 mg/kg × 20 days). The heart weight (P < 0.01) and its percentage of the body weight (P < 0.001) were significantly higher in these two groups than in the controls. Similarly, in the noradrenaline 4 mg/ kg × 30 days group, the body weight was significantly (P < 0.001) reduced and the heart weight (P < 0.01) and its percentage of body weight (P < 0.001) were significantly higher than in the controls. In comparing the cocaine and noradrenaline experiments, the frequency and extent of cardiac lesions obtained with 40 mg/kg × 10 days + 60 mg/kg × 20 days of cocaine were similar to those with 8 mg/kg of noradrenaline at 24 h. In this experimental model, cocaine administration compromised the antioxidant defence system of the heart associated with a significant increase of heart weight and the percentage of body weight.

Enzymatic–nonenzymatic cellular antioxidant defense systems response and immunohistochemical detection of MDMA, VMAT2, HSP70, and apoptosis as biomarkers for MDMA (Ecstasy) neurotoxicity

3,4‐Methylenedioxymethamphetamine (MDMA)‐induced neurotoxicity leads to the formation of quinone metabolities and hydroxyl radicals and then to the production of reactive oxygen species (ROS). We evaluated the effect of a single dose of MDMA (20 mg/kg, i.p.) on the enzymatic and nonenzymatic cellular antioxidant defense system in different areas of rat brain in the early hours (<6 hr) of the administration itself, and we identified the morphological expressions of neurotoxicity induced by MDMA on the vulnerable brain areas in the first 24 hr. The acute administration of MDMA produces a decrease of reduced and oxidized glutathione ratio, and antioxidant enzyme activities were significantly reduced after 3 hr and after 6 hr in frontal cortex. Ascorbic acid levels strongly increased in striatum, hippocampus, and frontal cortex after 3 and 6 hr. High levels of malonaldehyde with respect to control were measured in striatum after 3 and 6 hr and in hippocampus and frontal cortex after 6 hr. An immunohistochemical investigation on the frontal, thalamic, hypothalamic, and striatal areas was performed. A strong positive reaction to the antivesicular monoamine transporter 2 was observed in the frontal section, in the basal ganglia and thalamus. Cortical positivity, located in the most superficial layer was revealed only for heat shock protein 70 after 24 hr.

Chronic nandrolone administration promotes oxidative stress, induction of pro-inflammatory cytokine and TNF-α mediated apoptosis in the kidneys of CD1 treated mice

Nandrolone decanoate administration and strenuous exercise increase the extent of renal damage in response to renal toxic injury. We studied the role played by oxidative stress in the apoptotic response caused by nandrolone decanoate in the kidneys of strength-trained male CD1 mice. To measure cytosolic enzyme activity, glutathione peroxidase (GPx), glutathione reductase (GR) and malondialdehyde (MDA) were determined after nandrolone treatment. An immunohistochemical study and Western blot analysis were performed to evaluate cell apoptosis and to measure the effects of renal expression of inflammatory mediators (IL-1β, TNF-α) on the induction of apoptosis (HSP90, TUNEL). Dose-related oxidative damage in the kidneys of treated mice is shown by an increase in MDA levels and by a reduction of antioxidant enzyme GR and GPx activities, resulting in the kidneys reduced radical scavenging ability. Renal specimens of the treated group showed relevant glomeruli alterations and increased immunostaining and protein expressions, which manifested significant focal segmental glomerulosclerosis. The induction of proinflammatory cytokine expression levels was confirmed by Western blot analysis. Long-term administration of nandrolone promotes oxidative injury in the mouse kidneys. TNF-α mediated injury due to nandrolone in renal cells appears to play a role in the activation of both the intrinsic and extrinsic apoptosis pathways.

Diffuse axonal injury and oxidative stress: A comprehensive review

Traumatic brain injury (TBI) is one of the world’s leading causes of morbidity and mortality among young individuals. TBI applies powerful rotational and translational forces to the brain parenchyma, which results in a traumatic diffuse axonal injury (DAI) responsible for brain swelling and neuronal death. Following TBI, axonal degeneration has been identified as a progressive process that starts with disrupted axonal transport causing axonal swelling, followed by secondary axonal disconnection and Wallerian degeneration. These modifications in the axonal cytoskeleton interrupt the axoplasmic transport mechanisms, causing the gradual gathering of transport products so as to generate axonal swellings and modifications in neuronal homeostasis. Oxidative stress with consequent impairment of endogenous antioxidant defense mechanisms plays a significant role in the secondary events leading to neuronal death. Studies support the role of an altered axonal calcium homeostasis as a mechanism in the secondary damage of axon, and suggest that calcium channel blocker can alleviate the secondary damage, as well as other mechanisms implied in the secondary injury, and could be targeted as a candidate for therapeutic approaches. Reactive oxygen species (ROS)-mediated axonal degeneration is mainly caused by extracellular Ca2+. Increases in the defense mechanisms through the use of exogenous antioxidants may be neuroprotective, particularly if they are given within the neuroprotective time window. A promising potential therapeutic target for DAI is to directly address mitochondria-related injury or to modulate energetic axonal energy failure.

Weekly low-dose docetaxel in advanced non-small cell lung cancer previously treated with two chemotherapy regimens

BACKGROUND The role of salvage chemotherapy in advanced non-small cell lung cancer (NSCLC) is still controversial, but the recent development of a number of active antineoplastic agents has created new possibilities for disease management. The aim of this study was to evaluate the activity and safety of weekly docetaxel treatment in patients with advanced NSCLC previously treated with two chemotherapy regimens. PATIENTS AND METHODS The study involved 26 patients with histologically documented stage IIIB, IV or recurrent metastatic NSCLC previously treated with two non-taxane based-chemotherapy regimens. They all received docetaxel 25 mg/m(2)/week administered as a 1-h infusion in an outpatient setting with corticosteroid premedication. RESULTS Fourteen of the 26 patients (54%) had distant metastases and 12 (46%) chest-localised disease. Six patients (23%; confidence interval: 9.8-44.1%) showed a partial response, 8 (31%) stable disease, and 12 (46%) progressive disease. The median time to progression was 4 months (range 2-8), and the median survival was 7+ months (range 3-13+). There were no statistically significant differences between the global quality of life scores recorded at baseline and those recorded after subsequent cycles. The treatment was very well tolerated. CONCLUSION The results of this study suggest that weekly low-dose docetaxel is effective, well tolerated and maintains a relatively good quality of life in patients with advanced NSCLC previously exposed to two chemotherapy regimens.

Causes and Effects of Cellular Oxidative Stress as a Result of MDMA Abuse

3,4-methylenedioxymethamphetamine (MDMA, Ecstasy) is a substituted amphetamine with potent central nervous stimulant effects. Increasing evidence suggests that one way of MDMA-induced toxicity involves the production of reactive oxygen and reactive nitrogen species and a subsequent production of oxidative/nitrosative stress. The free radicals can originate from several molecular pathways (oxidative deamination of monoamine, metabolic pathways, cathecolamines autoxidation, and hyperthermia) and their harmful effect causing potential biological damage such as lipoperoxidation and cellular death. The role of oxidative stress in mediating MDMA toxicity is illustrated by decreases in the activity of the endogenous enzymatic and non enzymatic antioxidants observed in cells in vitro and in animals model. This review examines the available evidence for the involvement of oxidative stress in the mechanisms of MDMA-induced cellular damage with the aim to contribute to the understanding of the cellular and molecular mechanisms involved in MDMA toxicity.

Rapid and sensitive determination of piroxicam in rat plasma, muscle and skin by high-performance liquid chromatography

A rapid and precise high-performance liquid chromatographic method for the determination of piroxicam in a variety of biological samples has been developed. A reversed-phase column, isocratic elution and ultraviolet detection were employed. Calibration curves were reproducible and highly linear, with correlation coefficients typically averaging over 0.992. The detection limit of the assay was 100 ng/ml for all biological samples examined (at a signal-to-noise ratio of 3:1). Validation of the method demonstrated a good sensitivity, accuracy and precision. The method has been adopted for a pharmacokinetic study in rats.

L-2-OXOTHIAZOLIDINE-4-CARBOXYLIC ACID AND GLUTATHIONE IN HUMAN IMMUNODEFICIENCY VIRUS

Abstract The administration of L-2-oxothiazolidin-4-carboxylic acid (OTC) and glutathione (GSH) to modulate total GSH levels was examined in 24 men with human immunodeficiency virus (HIV) and 10 healthy HIV-seronegative control subjects. The mean blood GSH concentration in the control subjects was 1.65 ± 0.287 μmol/ml while that in the HIV-seropositive patients was 0.61 ± 0.248 μmol/ml. The oral administration of OTC 25 mg/kg and the intramuscular administration of GSH 800 mg/day in the HIV-seropositive subjects markedly increased the total GSH levels. These results suggest that a systemic decrease in GSH levels could be one of the factors involved in the immunodeficiency of HIV-seropositive patients.