Aleksandra Michalak

Effects of chronic exposure to lead, cadmium, and manganese mixtures on oxidative stress in rat liver and heart

Abstract The aim of this study was to assess the effects of chronic combined exposure to low, environmental doses of Cd, Pb, and Mn on oxidative stress in the liver and heart of rats and on their liver function parameters. Male Wistar rats were divided randomly into eight groups. For nine months controls were receiving drinking water alone, whereas the exposed groups were receiving drinking water with Pb (0.2 mg L-1), Cd (1 mg L-1), and Mn (2 mg L-1) alone or in combinations. Malondialdehyde (MDA) significantly increased in both heart and liver of the animals after combined exposure to metals. Heart MDA correlated with blood Cd, Pb, and Mn and liver MDA with blood Cd. Aspartate aminotransferase (AST) activity and bilirubin concentration also increased significantly in the animal group exposed to all three metals and correlated positively with blood Cd, Pb, and Mn. Our study has confirmed the synergistic effect of the Cd, Mn, and Pb combination on the increase in heart MDA. A similar synergy was observed for Pb+Mn in the increase of serum alanine aminotransferase (ALT) activity as an indicator of liver function. Cilj je ovog istraživanja bio ocijeniti učinke kronične izloženosti kombinaciji Cd, Pb i Mn u niskim dozama kakve su u okolišu na oksidativni stres u jetrima i srcu štakora te na pokazatelje jetrene funkcije. U tu smo svrhu mužjake Wistar štakora nasumce podijelili u osam skupina, od kojih je kontrolna pila čistu vodu, a izložene skupine vodu pomiješanu s olovom (0,2 mg L-1), kadmijem (1 mg L-1) i manganom (2 mg L-1), zasebno ili u kombinacijama. Koncentracija malondialdehida (MDA) značajno se povećala u oba organa životinja izloženih kombinacijama metala. Srčani MDA korelirao je s razinama kadmija, olova i mangana u krvi, a jetreni MDA s razinom kadmija u krvi. Aktivnost aspartat aminotransferaza (AST) i koncentracije bilirubina također su bile značajno povišene u skupini izloženoj svim trima metalima te su korelirale s razinama kadmija, olova i mangana u krvi. Rezultati istraživanja potvrdili su da zajedno ova tri metala djeluju na povećanje MDA u srcu. Slična je sinergija zamijećena i između olova i mangana s obzirom na povećanje razine alanin aminotransferaze (ALT) u serumu, koji je pokazatelj jetrene funkcije.

[The correlations between aging of the human body, oxidative stress and reduced efficiency of repair systems].

The article presents an current knowledge overview about the importance of oxidative stress and reduced efficiency of repair processes during the aging process of the human body. Oxidative damage to cellular macromolecules (proteins, lipids, nucleic acids), are formed under the influence of reactive oxygen species (ROS). They are the part of important mechanism which is responsible for the process of aging and the development of many diseases. The most important effects result from DNA damage, due to the mutations formation, which can lead to the development of tumors. However, a well-functioning repair systems (i.a. homologous recombination) remove the damage and prevent harmful changes in the cells. Lipid peroxidation products also cause oxidative modification of nucleic acids (and proteins). Proteins and fats also have repair systems, but much simpler than those responsible for the repair of nucleic acids. Unfortunately, with increasing age, they are more weakened, which contributes to increase numbers of cell damage, and consequently development of diseases specific to old age: cancer, neurodegenerative diseases or atherosclerosis.

Effects of chronic exposure to lead, cadmium, and manganese mixtures on oxidative stress in rat liver and heart / Utjecaj kronične istodobne izloženosti olovu, kadmiju i manganu na oksidativni stres u jetri i srcu štakora

Abstract The aim of this study was to assess the effects of chronic combined exposure to low, environmental doses of Cd, Pb, and Mn on oxidative stress in the liver and heart of rats and on their liver function parameters. Male Wistar rats were divided randomly into eight groups. For nine months controls were receiving drinking water alone, whereas the exposed groups were receiving drinking water with Pb (0.2 mg L-1), Cd (1 mg L-1), and Mn (2 mg L-1) alone or in combinations. Malondialdehyde (MDA) significantly increased in both heart and liver of the animals after combined exposure to metals. Heart MDA correlated with blood Cd, Pb, and Mn and liver MDA with blood Cd. Aspartate aminotransferase (AST) activity and bilirubin concentration also increased significantly in the animal group exposed to all three metals and correlated positively with blood Cd, Pb, and Mn. Our study has confirmed the synergistic effect of the Cd, Mn, and Pb combination on the increase in heart MDA. A similar synergy was observed for Pb+Mn in the increase of serum alanine aminotransferase (ALT) activity as an indicator of liver function. Cilj je ovog istraživanja bio ocijeniti učinke kronične izloženosti kombinaciji Cd, Pb i Mn u niskim dozama kakve su u okolišu na oksidativni stres u jetrima i srcu štakora te na pokazatelje jetrene funkcije. U tu smo svrhu mužjake Wistar štakora nasumce podijelili u osam skupina, od kojih je kontrolna pila čistu vodu, a izložene skupine vodu pomiješanu s olovom (0,2 mg L-1), kadmijem (1 mg L-1) i manganom (2 mg L-1), zasebno ili u kombinacijama. Koncentracija malondialdehida (MDA) značajno se povećala u oba organa životinja izloženih kombinacijama metala. Srčani MDA korelirao je s razinama kadmija, olova i mangana u krvi, a jetreni MDA s razinom kadmija u krvi. Aktivnost aspartat aminotransferaza (AST) i koncentracije bilirubina također su bile značajno povišene u skupini izloženoj svim trima metalima te su korelirale s razinama kadmija, olova i mangana u krvi. Rezultati istraživanja potvrdili su da zajedno ova tri metala djeluju na povećanje MDA u srcu. Slična je sinergija zamijećena i između olova i mangana s obzirom na povećanje razine alanin aminotransferaze (ALT) u serumu, koji je pokazatelj jetrene funkcije.

Utjecaj kronične istodobne izloženosti olovu, kadmiju i manganu na oksidativni stres u jetri i srcu štakora

Abstract The aim of this study was to assess the effects of chronic combined exposure to low, environmental doses of Cd, Pb, and Mn on oxidative stress in the liver and heart of rats and on their liver function parameters. Male Wistar rats were divided randomly into eight groups. For nine months controls were receiving drinking water alone, whereas the exposed groups were receiving drinking water with Pb (0.2 mg L-1), Cd (1 mg L-1), and Mn (2 mg L-1) alone or in combinations. Malondialdehyde (MDA) significantly increased in both heart and liver of the animals after combined exposure to metals. Heart MDA correlated with blood Cd, Pb, and Mn and liver MDA with blood Cd. Aspartate aminotransferase (AST) activity and bilirubin concentration also increased significantly in the animal group exposed to all three metals and correlated positively with blood Cd, Pb, and Mn. Our study has confirmed the synergistic effect of the Cd, Mn, and Pb combination on the increase in heart MDA. A similar synergy was observed for Pb+Mn in the increase of serum alanine aminotransferase (ALT) activity as an indicator of liver function. Cilj je ovog istraživanja bio ocijeniti učinke kronične izloženosti kombinaciji Cd, Pb i Mn u niskim dozama kakve su u okolišu na oksidativni stres u jetrima i srcu štakora te na pokazatelje jetrene funkcije. U tu smo svrhu mužjake Wistar štakora nasumce podijelili u osam skupina, od kojih je kontrolna pila čistu vodu, a izložene skupine vodu pomiješanu s olovom (0,2 mg L-1), kadmijem (1 mg L-1) i manganom (2 mg L-1), zasebno ili u kombinacijama. Koncentracija malondialdehida (MDA) značajno se povećala u oba organa životinja izloženih kombinacijama metala. Srčani MDA korelirao je s razinama kadmija, olova i mangana u krvi, a jetreni MDA s razinom kadmija u krvi. Aktivnost aspartat aminotransferaza (AST) i koncentracije bilirubina također su bile značajno povišene u skupini izloženoj svim trima metalima te su korelirale s razinama kadmija, olova i mangana u krvi. Rezultati istraživanja potvrdili su da zajedno ova tri metala djeluju na povećanje MDA u srcu. Slična je sinergija zamijećena i između olova i mangana s obzirom na povećanje razine alanin aminotransferaze (ALT) u serumu, koji je pokazatelj jetrene funkcije.