Whole blood glutathione peroxidase and erythrocyte superoxide dismutase activities, serum trace elements (Se, Cu, Zn) and cardiovascular risk factors in subjects from the city of Ponta Delgada, Island of San Miguel, The Azores Archipelago, Portugal.

Activities of whole blood glutathione peroxidase (GSH-Px) and erythrocyte superoxide dismutase (SOD) and serum levels of selenium (Se), copper (Cu) and zinc (Zn) were measured in 118 apparently healthy subjects aged 20-60 years from the city of Ponta Delgada, Island of San Miguel, The Azores Archipelago, Portugal. Data were analysed by age/gender, lipid profile and blood pressure as cardiovascular risk factors searching for their relevance when assessing reference values for antioxidant biomarkers. GSH-Px was in the same range, but SOD was significantly lower than in other Portuguese populations. Neither activity differed with gender. GSH-Px activity increased with age, namely in normolipidemic men versus the hyperlipidemic group in which a decrease was observed. This suggests a progressive impairment of GSH-Px with age caused by an enhanced production of oxidant species in hyperlipidemia. GSH-Px was 30% lower in male hypertensives versus normotensives. SOD activity did not relate to age or blood pressure but was 17% higher in the hyperlipidemic men versus the normolipidemic group, suggesting a better antioxidant protection by SOD than by GSH-Px in hyperlipidemia and hypertension. Se was higher in men versus women, particularly in the older subjects, and partly related to hyperlipidemia. Zn levels showed a similar dependency on gender, not related to age or lipid profile. Cu levels were much higher in women than in men in all age or lipid profile classes and decreased in hyperlipidemia. They were lowered with age in both genders, particularly in normolipidemic women. The present research therefore suggests that hyperlipidemia and hypertension do affect antioxidant status and should be considered when assessing antioxidant biomarkers in blood.

An assessment of time-dependent effects of lead exposure in algerian mice (Mus spretus) using different methodological approaches.

Time-dependent effects of lead (Pb) toxicity were studied in Algerian mice (Mus spretus) treated with Pb acetate via drinking water (1 g Pb acetate/L) for different periods of exposure (15, 45, and 90 d). End points included the determination of hepatic Pb concentration and the assessment of some morphophysiological, biochemical and cytogenetical parameters. A control group receiving distilled water was also monitored for comparative purposes. Hepatic Pb accumulation increased with the time of exposure and was significantly higher in treated mice when compared to controls. In association with significant body mass loss in Pb-exposed mice, for 15 and 45 d, a significant increase in the relative spleen mass was observed after 45 d of intoxication. Pb-exposed mice also showed significant decreases in red blood cells, hematocrit, and mean corpuscular hemoglobin. On the contrary, changes in plasma transferases (aspartate aminotransferase and alanine aminotransferase) and hepatic superoxide dismutase activities did not reach statistical significance. A significant increase in the frequency of micronucleated polychromatic bone marrow erythrocytes was also found in the 90-d-exposed mice, compared to nontreated mice and the other exposed groups. Exposure to Pb acetate resulted also in a slight time-dependent decrease of the polychromatic-normochromatic ratio. These results support the concept that a long-term chronic exposure to Pb induced alterations upon some morphophysiological and genetic parameters in Algerian mice.

Trace element status (Se, Cu, Zn) in healthy Portuguese subjects of Lisbon population: a reference study.

Serum levels of selenium, copper, and zinc were systematically determined in healthy subjects of the Lisbon population. The sample consisted of 183 blood donors of both genders who were divided into two age groups: 20-44 and 45-70 yr of age; relationships with gender, age, the lipid profile, and tobacco consumption were investigated. In the female group, the intake of oral contraceptives and pregnancy were considered for the youngest women, and hormonal replacement therapy (HRT) was taken into account for the oldest ones. Serum concentrations of these elements were in the same range as those found for populations of other European countries. Differences between genders were observed for the three elements studied, with serum selenium and zinc concentrations higher in men and copper levels higher in women. Age-dependent differences were found for selenium: The oldest subjects (regardless gender) presented the highest concentrations of selenium in serum as further demonstrated by the positive correlation with age. In both pregnant and contraceptive-using women, copper was greatly increased, confirming the influence of estrogen status and/or oral contraceptive intake on increased serum copper levels. However, in postmenopausal women, HRT did not significantly affect serum copper levels. Selenium, copper, and zinc status were not different between normolipidemic and hyperlipidemic subjects for the same gender and age range, but selenium levels tended to increase with hyperlipidemia when considering the whole group of subjects. With respect to the lifestyle, higher serum zinc levels were found in tobacco-consuming men. Albumin serum levels were similar for all considered subgroups, except for the pregnant women, for whom a decrease in this parameter was observed. The present study allowed one to obtain reference values for this healthy group of population, which will serve for a comparative study with groups having pathological conditions, such as cardiovascular disease.

Systemic markers of the redox balance in chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is highly prevalent and its pathogenesis is still not completely clarified. Clinically stable patients (n=21) and healthy subjects (n=24) were studied for blood markers of oxidative injury and antioxidant status. The plasma concentration of protein carbonyls was significantly increased in COPD patients, both ex-smokers (0.76 +/- 0.28 nmol mg(-1)) and smokers (0.99 +/- 020 nmol mg(-1)) versus controls (0.49 +/- 0.14 nmol mg(-1)) . The concentration of total thiols was slightly enhanced in plasma of the COPD patients (ex-smokers 492 +/- 23 micromol 1(-1) and smokers 505 +/- 36 micromol 1(-1) versus controls 450 +/- 67 micromol 1(-1); p < 0.05). The activity of the antioxidant enzyme superoxide dismutase was increased in erythrocytes (activity in U g(-1) haemoglobin; ex-smokers 4460 +/- 763 and smokers 4114+/- 1060 versus 3015 +/- 851 in controls; p > 0.01), while glutathione peroxidase activity was decreased in total blood (activity in U g(-1) haemoglobin: ex-smokers 27 +/- 9 and smokers 23 +/- 9 versus 47 +/- 25; p < 0.01). Lower levels of selenium in plasma were also found for COPD patients (concentration in mg 1(-1): ex-smokers 0.030 +/- 0.019 and smokers 0.032 +/- 0.024 versus 0.058 +/- 0.023 in controls; p < 0.01), being more evident in those with very low levels of arterial oxygen pressure. In addition, the levels of potassium and rubidium were increased in blood cells of the patient group. All these changes might reflect oxidant damage and an altered electrolytic homeostasis, and can be interpreted as markers of COPD rather than as indicators of smoking habits.

Hepatic elemental contents and antioxidant enzyme activities in Algerian mice (Mus spretus) inhabiting a mine area in central Portugal.

In this study the effects of heavy metals (manganese, iron, copper, zinc) and selenium exposure on the hepatic activity of antioxidant enzymes, superoxide dismutase (SOD) and glutathione S-transferases (GST), were appraised on a seasonal basis in Algerian mice (Mus spretus) inhabiting an active copper mine area. A reference population of the same species was considered for comparative purposes. Different patterns of seasonal variation were found in both populations for the manganese, iron and selenium hepatic concentrations and SOD activity. When the two populations were compared, iron and selenium concentrations were enhanced in mice from the polluted area. In addition, SOD activity was significantly decreased in summer in exposed mice, but no other significant changes in SOD and GST activities between sites throughout the year were recorded. However, when seasonal data within each group of mice were pooled, significant differences were found between sites for the average concentrations of manganese, iron and selenium, which are higher in the polluted site. In addition, significant differences were obtained for the average values of SOD and of GST activities, due to simultaneously higher GST values and slightly lower SOD values in the polluted site. The population from the reference site was more homogeneous for all parameters measured than the population from the polluted area. These results, in particular the higher variability in data collected from mice exposed to heavy metals and selenium, combined with the negative associations between biochemical markers and heavy metals, may suggest, despite the good adaptability of the mice to their habitat, biochemical stress due to diminished environmental quality.

Comparison of whole-blood glutathione peroxidase activity, levels of serum selenium, and lipid peroxidation in subjects from the fishing and rural communities of "Rabo de Peixe" village, San Miguel Island, the Azores' Archipelago, Portugal.

The activity of glutathione peroxidase (GSH-Px), serum selenium (Se), and thiobarbituric acid reactive substances (TBARS) were measured in the whole blood of 148 healthy adults aged 20-60 yr from the fishing and rural communities of "Rabo de Peixe," The Azores, Portugal. The subjects did not live in the same household and had different socioeconomic profiles and dietary habits. The serum lipid profile and selected life habits were also considered in this study. No significant differences in the activity of GSH-Px were found in the interpopulation or intrapopulation analyses, classified by age or lipid profile. An age-dependent GSH-Px increase was noted in the younger male (M) subgroups (20-39 yr). The Se levels were higher in fishers (f) of both genders (M, F) than in subjects living in the rural (r) environment: 110+/-25 microg/L (f, M), 89+/-20 microg/L (f, F), 88+/-22 microg/L (r, M) and 80+/-17 microg/L (r, F). In the fishers, but not in the rural population, Se was higher in the males, but it did not show significant variation with age. The levels of TBARS were lower in the f than in the r male group. The Se level was lower and TBARS higher in the hyperlipemic women in the f group, compared to the corresponding controls. Our results suggest that the fishers (mainly men) show a better antioxidant status than that of their rural counterparts, due to differences in dietary habits between the study populations and between genders.

Response of antioxidant enzymes in freshwater fish populations (Leuciscus alburnoides complex) to inorganic pollutants exposure.

Evidence is accumulating indicating the importance of antioxidant enzyme activity measurements in eco-toxicological studies, as they may constitute markers for exposure to a large variety of pollutants. Variation of antioxidant enzymes, superoxide dismutase (SOD) and glutathione S-transferases (GST) and the effect of heavy metals and selenium exposure on these enzymes were investigated in the livers of Iberian endemic minnows (Leuciscus alburnoides complex) captured in a copper (Cu) mining area. Higher hepatic levels of copper and selenium were always observed in fish captured at the polluted site relative to the reference area population, reflecting the environmental monitoring results. A seasonal fluctuation in zinc and selenium levels for both populations was also observed which could be related to gonad maturation. The activity of SOD did not show significant regional alterations, but a seasonal variation occurred presumably associated with the Leuciscus life cycle. The GST activity was higher in the fish population from the polluted area (except in spring) and GST variability was associated with selenium and copper levels when both regions were compared. The increased GST activity was probably a metabolic adaptation to the continuous exposure to higher levels of those elements.

Trace element status (Se, Cu, Zn) and serum lipid profile in Portuguese subjects of San Miguel Island from Azores'archipelago.

Data on selenium, copper and zinc in serum of Portuguese inhabitants of the city of Ponta Delgada-Azores Archipelago are reported for the first time. The subjects are of both sexes, aged 20 to 60 years, and non-abusers of alcohol, tobacco or drugs. Serum concentrations of these elements are in the same range than those found for populations of Lisbon and of some other European countries. Differences between sexes are observed, with serum selenium and zinc levels being higher in males than in females, and the copper levels being higher in females as compared to males. These results can be explained by the hormonal status and/or oral contraceptive steroids intake, particularly for copper. Concerning lipid profile, the majority of individuals have serum lipid parameters within the normal range. In addition, no difference in trace element levels between normo and hyperlipidemic individuals is observed and no conclusive results about the relationship of all evaluated parameters to alcohol, tobacco and drug consumption are observed, in agreement with data obtained in the population of Lisbon.

Selenium and lipid parameters in plasma of Portuguese subjects.

To obtain further insight into the role of selenium in the development of atherosclerosis, plasma selenium and lipid parameters were determined in 126 Portuguese subjects living in the region of Lisbon, 60 women and 66 men, 20-60 years old, divided up in to three groups according to their plasma lipid profile: Group I consisted of normolipidemic subjects having plasma triglycerides and total cholesterol < 200mg/dL; Group II was composed of hypercholesteremic subjects with total cholesterol > 200mg/dL and plasma triglycerides < 200mg/dL; Group III was composed of hypercholesteremic and hypertriglyceremic subjects having total cholesterol and plasma triglycerides > 200mg/dL. Respective values for mean plasma selenium (+/- SD) in the groups were: 93 +/- 18 micrograms/L, 90 +/- 17 micrograms/L and 96 +/- 18 micrograms/L. A weak significant difference in plasma selenium between women and men was, however, observed in Group I (87 +/- 20 micrograms/L vs. 100 +/- 11 micrograms/L, p < 0.05). Regression analysis showed no significant relationship between plasma selenium and lipid parameters, except in the most hyperlipidemic women of Group III, where a weak correlation between plasma selenium and the HDL-cholesterol/total cholesterol ratio (r = 0.80, p < 0.05) was observed. The present study suggests that the relationship between selenium and HDL-cholesterol has to be further examined, taking into account nutritional, metabolic and genetic factors.