ERITROCITNI ANTIOKSIDATIVNI ENZIMI MALONDIALDEHID, LIPIDNA HIDROPEROKSIDAZA I SELENIUM U RADNIKA RUDNIKA ŽIVE
Prezelj M 1, Briski A 1, Krsnik M 1, Osredkar J 1, Horvat M 2, Kobal A 3.
1 University Medical Center Ljubljana, Institute of Clinical Chemistry and Biochemistry, Ljubljana, Slovenia;
2 Department of Environmental Sciences Jozef Stefan Institute Ljubljana, Slovenia;
3 Idrija Mercury Mine, Idrija, Slovenia

CILJ: Istraživana je uloga markera oksidativnog stresa: eritrocitnih antioksidativnih enzima u aktivnosti superoksid dismutaze (SOD), katalaze (CAT), glutathione peroksidaze (GPx), i seleniuma (Se), lipidne hidroperoksidaze (LOOH) i malondialdehida (MDA) u rudara nakon profesionalne, dugotrajne ekspozicije živi (Hg0).

ISPITANICI I METODE: Komparirane su vrijednosti u 54 rudara žive sa vrijednostima 58 ispitanika kontrolne grupe, koji nisu bili profesionalno, a ni u životnoj okolini izloženi Hg0. Ekspozicija Hg0 u rudara rangirana je od 7 to 31 godina, vremenski udružene vrijednosti Hg u urinu su varirale kroz ekspozicioni period od 794 to 11365 µgHg/L. Aktivnosti antioksidantnih enzima su determinirane u eritrocitima. SOD aktivnosti su bile ocijenjene enzimatskim kolorimetrijskim testovima GPx (RANDOX), and CAT aktivnosti (po metodi Aebi), izmjerene sa enzimatskim UV testom. Se koncentracije su određene u plazmi i urinu na Zeeman AAS (Varian, Australia) i koncentracije Hg su određivane AAS metodom hladne pare, koncentracije MDA u urinu su procjenjene kapilarnom zona elektroforezom, dok su koncentracije LOOH bile praćene u plazmi kolorimetrijskim testom (OXIS). Statistička obrada podataka urađena je upotrebom Mann-Whitney testa i linearne regresione analize.

REZULTATI: Otkrivene su signifikantno povećane vrijednosti CAT aktivnosti u grupi rudara, (p<0.0002)kao i urinarne Hg (P<0.002), Se (P<0.05), i koncentracije MDA (P<0,01), dok su koncentracije Se u plazmi bile signifikantno niže (P<0.005). Nije utvrđena statistički značajna razlika observiranih SOD activnosti i koncentracije LOOH u plazmi. GPx activnost bila je niža u grupi rudara nego u kontrolnoj grupi, ali razlike nisu bile signifikantne. Nivo Hg u urinu pozitivno je korelirao sa CAT activnostima i koncentracijom Se u urinu. Negativna korelacija otkrivena je između nivoa Se u urinu i aktivnosti GPx, kao i SOD i CAT aktivnosti.

ZAKLJUČAK: Prema rezultatima studije ekspozicija Hg0 u rudarskih radnika uzrokuje povećanu aktivnost CAT, Hg u urinu, Se and koncentracije MDA i pad nivoa Se u plazmi. Postojanje umjerenih količina tipova reaktivnog oksigena može biti rezultat akumulacije Hg u tijelu.


ERYTHROCYTE ANTIOXIDANT ENZYMES, MALONDIALDEHYDE, LIPID HYDROPEROXIDES AND SELENIUM IN MERCURY MINE WORKERS
Prezelj M 1, Briski A 1, Krsnik M 1, Osredkar J 1, Horvat M 2, Kobal A 3.
1 University Medical Center Ljubljana, Institute of Clinical Chemistry and Biochemistry, Ljubljana, Slovenia;
2 Department of Environmental Sciences Jozef Stefan Institute Ljubljana, Slovenia;
3 Idrija Mercury Mine, Idrija, Slovenia

AIM: The role of erythrocyte antioxidant enzyme activities superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and selenium (Se), lipid hydroperoxides (LOOH), malondialdehyde (MDA) as markers of oxidative stress in miners after long-term occupational exposure to the elemental mercury vapour (Hg0) were investigated.

SUBJECTS AND METHODS: Values of 54 mercury miners and 58 people, as control group with no occupational and environmental Hg0 exposure, were compared. The exposure to Hg0 of miners ranged from 7 to 31 years, the time integrated urine Hg from to whole exposure period varied in urine 794 to 11365 µgHg/L. The antioxidant enzyme activities were determined in erythrocytes. SOD activity was assessed by enzymatic colorimetric test GPx (RANDOX), and CAT activity (the method of Aebi) were measured by enzymatic UV test. Se concentration was determined in plasma and urine by the Zeeman AAS (Varian, Australia) and Hg concentration was measured in urine by cold vapour AAS, MDA concentration in urine was assessed by capillary zone electrophoresis, whereas LOOH concentration was evaluated in plasma by colorimetric test (OXIS). The dates assessed by using Mann-Whitney test and linear regression analysis.

RESULTS: There was a significant increase in the miner group in CAT activity (p<0.0002), urinary Hg (P<0.002), Se (P<0.05), and MDA concentration (P<0,01), whereas plasma Se concentration was significantly lower (P<0.005). No significant differences were observed in SOD activity and plasma LOOH concentration. GPx activity was lower in the miner group than in the control group but the difference was not significant. Urinary Hg levels were positively correlated with CAT activities and urinary Se concentrations. Negative correlation was found between urinary Se levels and GPx activities as well as SOD and CAT activities.

CONCLUSION: The results of the present study has shown that chronic exposure to Hg0 in the mine workers causes increased activity of CAT, urinary Hg, Se and MDA concentration and decreased plasma Se level. That is probably due to the formation of a moderate quantity of reactive oxygen species as a result of Hg accumulation in the body. .

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