Z Gastroenterol 2005; 43 - 158
DOI: 10.1055/s-2005-869805

Molecular biologocal relevances of metal element concentrations during hepatic ischaemia-reperfusion

L Váli 1, K Szentmihályi 2, G Taba 2, H Fébel 3, I Kocsis 1, J Fehér 1, A Blázovics 1
  • 12nd Dept of Medicine, Semmelweis Egyetem, Budapest
  • 2MTA KKKI
  • 3Institute Of Animal Husbandry and Fodder Research, Herceghalom

Introduction Ischaemia-reperfusion is considered as one of the main risk factors during operations on the liver. The presence of oxidative stress is well known in the literature. Our aim was to elucidate the connection between the alterations of metal element concentrations and the redox defensive system.

Methods Wistar rats were divided into control, sham operated (S), ischaemic and reperfusion (R) groups. Hepatic ischaemia was induced for 45 minutes, which was followed by 15 minutes of reperfusion. Metal concentrations of the liver were determined with ICP-OES. H-donating ability (HDA), reducing power (RP), TAS, GSHPx and SOD activity of the liver were detected by spectrofotometry.

Results HDA (36.07±2.03 vs. 32.08±1.32 inhibition%) and RP (0.682±0.017 vs. 0.502±0.050 mmolAS/ml) were decreased during reperfusion. GSHPx level of liver was significantly decreased (313.31±48.11 vs. 246.71±19.17 U/l), TAS and SOD showed the same tendency. The concentration of Zn decreased significantly (S: 11.809±1.231 vs. R: 8.743±0.243), as well as Mg (S: 82.97±8.08 vs. R: 63.92±2.51) and Fe (S: 80.12±34.18 vs. R: 49.18±11.40). There was significant rise in the content of Al (S: 3.536±0.687 vs. R: 3.536±0.687) and Ca (S: 35.50±1.13 vs. R: 59.83±25.07).

Discussion Molecular biological background: Free radicals and heavy metal elements induce the function of MTF-1 transcription factor, wich regulates the transcription of metallothionein genes. The loss in the concentration of Zn may be an explanation for the decreased SOD activity. This element is needed for the induction of NF-kB, as well. ATP production requires Mg, therefore the decreased Mg content may lead to the necrosis of the hepatocytes. The increased Ca content may lead to apoptosis through the release of cytochrome c. High Al level of the liver emphasises the low activity of metallothionein enzymes, which are responsible for the detoxification and elimination of heavy metal elements. We conclude, that more attention should be paid to the changes of the metal elements under pathologic circumstances.

Support: NKFP-1A/005/2004, 1B/047/2004.