Mg Tozzi-Ciancarelli

Urinary nitric oxide metabolites and lipid peroxidation by‐products in migraine

Enhanced endothelium nitric oxide (NO) and superoxide anion release may cause migraine through related cerebral blood flow changes. Thirty subjects suffering from migraine with and without aura and 20 healthy controls were investigated. Urine samples collected for 24 h during and after the migraine attack, and during the headache-free period, were assayed for urinary NO stable metabolites (NOx) and thiobarbituric acid reactive substances (TBARS). During the headache-free period urinary NOx and TBARS levels were higher in migraine sufferers than in controls (NOx 0.77 ± 0.14 vs. 0.28 ± 0.15 mmol/mmol creatinine, P < 0.05; TBARS 0.40 ± 0.19 vs. 0.26 ± 0.13 μmol/mol creatinine, P < 0.05). Also, NOx excretion was higher during the headache-free period than during or after the migraine attack (P < 0.05). Urinary TBARS were increased during the attack with respect to the headache-free period (P < 0.05). No differences were observed in the same parameters between sufferers of migraine with and without aura. Urinary NOx and TBARS might be promising as markers of their systemic levels to evaluate the increased vulnerability to oxidative stress in migraine sufferers.

Influence of acute exercise on human platelet responsiveness: possible involvement of exercise-induced oxidative stress

Abstract. The aim of this study was to evaluate in sedentary male subjects the effects of an acute bout of strenuous and moderate exercise on ex vivo platelet responsiveness and its possible relationship with exercise-associated modifications of oxidant-antioxidant status. An increased ADP- and collagen-evoked platelet aggregation associated with modified membrane fluidity and ion homeostasis was observed after exhaustive exercise. After moderate exercise, we found a decrease of platelet aggregation evoked by low concentrations of agonists. Strenuous exercise, but not moderate exertion, resulted in the enhanced accumulation of secondary products of lipid peroxidation, decreased total antioxidant capacity, including a diminished superoxide dismutase activity, and increased susceptibility of low-density lipoprotein (LDL) to in vitro oxidation. Acute elevation of plasma nitrite/nitrate (NOX) content was observed following each single session of physical test, whilst the platelet NOX content was decreased after strenuous exercise and increased after moderate exercise. Findings of the present study suggest that oxidative stress induced by acute strenuous exercise may interfere with platelet responsiveness most likely by promoting oxidized LDL-mediated platelet activation and by decreasing plasma and platelet-derived nitric oxide (NO) bioactivity. Moreover, our results further suggest that platelet responsiveness following an acute moderate physical stressor may depend on the efficiency of plasma and intraplatelet NO to desensitize platelets to agonist stimulation.

Possible involvement of plasma antioxidant defences in training-associated decrease of platelet responsiveness in humans

The aim of this study was to evaluate in sedentary individuals the effects of a 20-week exercise training program on ex vivo platelet responsiveness and the possible involvement of plasma antioxidant defences in relation to the mechanisms controlling platelet sensitivity. A statistically significant decrease in ADP- and collagen-evoked platelet aggregation was observed after physical training together with an increase in plasma total antioxidant capacity (TEAC), superoxide dismutase activity, and high-density lipoprotein cholesterol (HDL-C) concentration. Additionally, a rise in lag time for in vitro low-density lipoprotein (LDL) oxidation as well as a decreased plasma level of secondary products of lipid peroxidation were observed after training, and the values for lag time were significantly correlated with TEAC and HDL-C. Nitrate/nitrite (NOx) content both in plasma and in platelet cytosol was significantly enhanced at the end of the training period and a significant positive correlation was found between plasma and intraplatelet NOx values. Furthermore, intraplatelet NOx content was positively correlated with HDL-C levels. The findings of the current study suggest that the improvement of antioxidant defences induced by moderate regular exercise may be involved in desensitising blood platelets most likely through the inhibition of LDL oxidation and the simultaneous enhancement of plasma and intraplatelet NOx bioavailability and HDL-C level.

Helicobacter pylori infection and migraine.

The study is aimed to ascertain whether the Helicobacter pylori (Hp) infection is responsible for the vulnerability to oxidative stress observed in migraineurs. Hp sero-logical positivity was assessed by ELISA evaluation of specific IgA and IgG antibodies in 30 subjects (11 males and 19 females) suffering from migraine without aura during the headache-free period. The Hp infection was detected in 16.7% of migraineurs. Plasma accumulation of peroxidative substances (TBA-RS), an index of systemic oxidative status, was increased in migraineurs without Hp infection with respect to controls (P< 0.001), while no significant differences of TBA-RS were found in migraineurs with or without Hp infection. Unmodified values of plasma nitrite/nitrate concentrations, expression of systemic nitric oxide (NO), were obtained in migraineurs in comparison to controls indicating that Hp infection does not modify the plasma oxidative status and the systemic NO bioavailability of migraineurs. In conclusion, our results do not support any specific correlation between Hp infection and migraine.

Relationship between biofeedback and oxidative stress in patients with chronic migraine

Chronic migraine (1.5.1) is burdened with headache-related disability. During noxious stimulation, changes of cerebral blood flow enhance the release of oxygen free radicals that react with nitric oxide (NO). We investigated the role of biofeedback in limiting migraine disability by influencing oxidative stress. Peroxides, NO and superoxide dismutase (SOD) were analysed in 20 female subjects with chronic migraine and in 20 female healthy controls before and after biofeedback sessions. NOx levels (23.7 ± 4.2 vs. 34.9 ± 4.6 μM; P < 0.05) and SOD activity (6.5 ± 1.0 vs. 8.0 ± 0.7 U/ml; P < 0.05) were lower in migraine sufferers before treatment than in healthy controls, whereas peroxide levels (145.8 ± 40.3 vs. 78.0 ± 20.0 μM; P < 0.05) were higher in migraine sufferers before treatment than in healthy controls. In migraine sufferers NOx levels (23.7 ± 4.2 vs. 31.3 ± 7.1 μM; P < 0.05) and SOD activity (6.5 ± 1.0 vs. 7.9 ± 0.9 U/ml; P < 0.05) were lower before than after treatment, whereas peroxide levels (145.8 ± 40.3 vs. 82.4 ± 21.1 μM; P < 0.05) were higher before than after treatment. SOD serum activity correlated positively with NOx serum levels and negatively with peroxide serum levels in healthy controls and in chronic migraine sufferers before and after biofeedback. The mean Migraine Disability Assessment Score before biofeedback sessions was higher than after treatment (36.9 ± 13.9 vs. 18.8 ± 10.4; P < 0.001). The effectiveness of biofeedback in limiting chronic migraine may be related to muscular relaxation associated with decreased oxidative stress accompanied by psychological well-being.

Flunarizine Effects on Oxidative Stress in Migraine Patients

Prophylactic activity of flunarizine in migraine is attributed to its antioxidant properties and to the relief of cerebral vasospasm in which nitric oxide (NO) is involved. We investigated the antimigraine activity of flunarizine and its influence on NO and oxidative marker bioavailability in 25 subjects suffering from migraine without aura and in 25 healthy controls. Urinary samples collected before and after treatment with flunarizine (5 mg orally per day for 6 months) were assayed for NO stable metabolites (NOx) and thiobarbituric acid reactive substances (TBARS). Urinary levels of NOx and TBARS were higher in migraine sufferers before treatment than in healthy controls. No differences were observed in NOx levels in migraine sufferers, before and after flunarizine treatment; urinary TBARS levels were decreased after flunarizine treatment (P < 0.05) and remained persistently higher than in healthy controls (P < 0.05). Our results suggest that flunarizine did not prevent NO-mediated vasodilatation, while it proved effective in limiting the oxidative reactions occurring in migraine sufferers.

Age-dependent changes in human erythrocyte properties

The focus of this paper is mainly directed on the role that the structural and functional perturbations of the erythrocyte membranes could have in the incidence of abnormal microcirculation which occur with the elderly. Rheological parameters of whole blood and the activity of some enzymes involved in erythrocyte metabolism and permeability are studied

Hemorheological parameters and body weight loss in obese children

(Received 30.7.1993; accepted 7.12.1993) Hemorheological parameters were analyzed on 50 simple type obese children after 12 months of an adequate diet and physical training. According to the changes of body weight, the subjects were divided into three groups. The hyperviscosity condition disappeared in obese children with a real weight loss, while it remained in the groups of subjects with persistent overweight and with increased weight. A decrease of erythrocyte membrane lipid peroxidation, expressed as malondialdehyde (MDA) , was observed only in the children with a real weight loss, suggesting that the persistent trend toward lipid peroxidation may be considered a significant risk factor for atherosclerosis.

Pregnancy-Induced Hypertension: Evidence for Altered Functional Features of Platelets

Objective: Among the pathogenetic factors of pregnancy-induced hypertension (PIH), oxidative damage seems to play a pivotal role. The aim of this study is to investigate if the oxidative status in patients with PIH could induce the altered platelet reactivity responsible for the abnormal uteroplacental microcirculation.Methods: Twenty pregnant women with PIH were admitted to our study. The presence of a mild hypertensive disorder was defined on the basis of blood pressure, proteinuria, and serum uric acid levels. Fifteen normotensive pregnant women and 15 nonpregnant women represented the control groups. The serum lipemic profile, including apoproteins, was measured to confirm that all subjects were normolipemic and, consequently, to avoid the influence of these parameters on platelet reactivity. Malondialdehyde (MDA), as an index of lipid peroxidation and cyclooxygenase pathway activation, was determined in plasma and in unstimulated and thrombin-stimulated platelets. Measurements of platelet membrane mi...