The effect of occupational exposure on pro/antioxidant balance in the blood of non-smoking and smoking smelters with diabetes.

Arsenic, lead and cadmium, potent environmental toxicants have been reported to induce diabetes mellitus, but their potential biological mechanism(s) have not been much investigated. The present study was designed to correlate parameters of pro/antioxidant balance with occupational exposure on heavy metals and smoking in smelters with diabetes compared on control group. The results showed a significant increase in the concentration of arsenic, cadmium and lead in the blood and urine of smelters, while smoking caused a further increase in the concentration of these metals. Increasing γ-glutamyltransferase activity and lead concentration due to occupational exposure in copper foundry, tobacco smoke and co-existing diabetes were observed. Also these factors have synergistic effects on metallothionein and glutathione concentrations as well as glutathione dependent enzymes activities. Our data suggests that sub-chronic arsenic, lead and cadmium exposure induces diabetic condition which may be mediated due to increased oxidative stress in blood.

Serum lipid peroxides and total antioxidant status in postmenopausal women on hormone replacement therapy.

Estradiol (E2) has antioxidant properties. The role of progestins in antioxidant defense is still unknown. We have evaluated the influence of E2 and E2 plus medroxyprogesterone acetate (MPA) on serum lipid peroxide (LPO) levels, a marker of free radical reactions, and serum total antioxidant status (TAS) in postmenopausal women. Subjects consisted of 26 women with surgical menopause, before and after 4 months of estrogen replacement therapy (ERT; E2), and 54 women with natural menopause on hormone replacement therapy (HRT; E2 plus MPA). Forty premenopausal women served as a control group. Serum E2 was estimated by radioimmunoassay, follicle-stimulating hormone by IRMA methods, LPO and TAS by colorimetric methods. Before therapy, LPO levels in the postmenopausal women were significantly higher (p < 0.001) than in the control group. After both ERT and HRT, LPO decreased significantly and did not differ between both groups and the control group. TAS was significantly lower in postmenopausal women (p < 0.001) than in the control group before therapy. After both ERT and HRT, TAS increased significantly and did not differ between both groups and the control group. We conclude that oxidative stress is increased after menopause. ERT and HRT inhibit the generation of free radicals and raise antioxidant potential to the levels found in premenopausal women. MPA did not influence the antioxidant action of E2.

Serum lipid peroxide levels and erythrocyte glutathione peroxidase and superoxide dismutase activity in premenopausal and postmenopausal women.

Free radical reactions are involved in processes connected with aging. Estradiol acts as antioxidant and free radical scavenger, but the mechanism of this action remains unknown. Estradiol has a hydroxyphenolic structure and may donate hydrogen atoms to lipid peroxyradicals to terminate chain reactions. There are a few reports concerning the influence of estradiol on natural antioxidant enzyme activity, such as superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT). The aim of this study was to estimate the relationship between the levels of estradiol and lipid peroxide (LPO), a marker of membrane lipid peroxidation, and the correlation between estradiol and erythrocyte SOD and GSH-Px activity. The study included 13 premenopausal and 13 postmenopausal healthy women. Serum levels of estradiol, follicle-stimulating hormone (FSH) and LPO, and erythrocyte SOD and GSH-Px activity were estimated in all subjects. Premenopausal women revealed significantly higher estradiol levels and lower LPO concentrations, as well as significantly higher GSH-Px activity than the postmenopausal group. SOD activity did not differ between the two groups. There was a negative correlation between serum estradiol and LPO levels as well as a positive correlation between estradiol and GSH-Px activity. These results support the hypothesis that estradiol exerts its antioxidant action not only through its chemical structure but probably also through its influence on natural cellular antioxidant enzyme activity.

[Vanadium: threat and hope]. / Wanad--zagrozenia i nadzieje.

Vanadium is an element classified in the group of heavy metals, very common in the natural environment and widely used in industry. It is mainly used in the production of nonferrous alloys, most resistant carbon steel, as well as in chemical, glass, paint and varnish, ceramic, and photographic industries. In the atmosphere, two second of vanadium originates from anthropogenic sources, sea-born aerosols and volcanic eruptions. Municipal waste is the major source of vanadium in surface water. It is one of the components of live organisms and participates in many biochemical processes essential for their proper functioning, but in higher concentrations it may induce acute or chronic intoxication that damage biological structures and disorder biochemical systems. The mechanism of vanadium toxic effect has not as yet been elucidated, however, it is already known that this mechanism is rooted among others in vanadium properties able to hinder a number of enzymatic systems. For vanadium the most "critical" systems are respiratory, urinary and hemopoietic. Vanadium salts may also be genotoxic and harmful at different phases of reproduction and development. Numerous studies of a possible use of vanadium in treatment of certain diseases, e.g., diabetes, have been carried out. Some findings on a potential antineoplastic or contraceptive effect of vanadium compounds have recently been reported. To sum up, there are numerous hazards associated with the wide industrial use of vanadium, nevertheless, the number of findings highlighting its nutritive and therapeutic properties is growing.

[Urinary trehalase activity as an indicator of renal dysfunction in lead smelters]. / Stezenie trehalazy w moczu jako wskaznik dysfunkcji nerek osób zawodowo narazonych na dzialanie olowiu.

Epidemiological and experimental studies have demonstrated that lead and cadmium are responsible for renal dysfunction. Urinary trehalase is known as a good marker of proximal tubular renal brush border destruction in the population environmentally exposed to cadmium. The aim of this study was to determine the impact of occupational exposure to lead on the renal function and urinary trehalase activity. The study was carried out in 68 workers, aged 46 +/- 6 years, employed in a copper foundry. Blood lead, cadmium, copper and manganese concentrations were measured by atomic absorption spectrophotometry. Urinary trehalase activity was determined by the method of Nakano and Itoh. Trehalase activity was increased in copper smelters as compared to controls. There also was a positive linear correlation between blood lead level and urinary trehalase activity (r = 0.44; p < 0.05). Negative correlations between blood lead and copper concentrations (r = -0.30; p < 0.05) and between serum copper and trehalase level (r = 0.68; p < 0.001) were found. The results show that urinary trehalase activity could be a good indicator of the renal brush border dysfunction in copper smelters. This marker could be useful in the early diagnosis of nephrotoxic effect of lead.

[The influence of cadmium on the circulatory system]. / Wplyw kadmu na uklad krazenia.

This review describes the effect of cadmium on the heart, blood vessels and different levels of the endocrine system of the organism, which are of essential importance to the circulatory system function. The results of the experimental studies on animals, on isolated blood vessels in vitro and on people professionally or environmentally exposed to cadmium were presented.