Posted by Jaynee on April 23, 2002, at 13:50:51
In reply to Re: iron and lack of response, posted by Jaynee on April 23, 2002, at 13:37:39
Another article for anyone interested.
The possible crucial role of iron accumulation combined with low
tryptophan, zinc and manganese in carcinogenesis.Johnson S.
Iron can react with citric acid, interfering with the Krebs cycle, hence with oxidative
phosphorylation. Free iron (Fe) can cause considerable oxidative damage both through Fenton
reactions and by activating xanthine oxidase, which produces both superoxide (O(2-)) and uric
acid (abundant in many cancers). It can also react with lactic acid, reducing its elimination and
increasing the acidity of the cytoplasm. Fe can also wreak havoc by reacting with tryptophan, the
least abundant and most delicate essential amino acid, which is necessary for the production of
serotonin and other substances required by the immune system to fight cancer. On the other
hand, in the presence of iron, the tryptophan metabolite quinolinate causes intense lipid
peroxidation. Similarly, several other carcinogenic metabolites of tryptophan are particularly
dangerous in the presence of Fe. Excess Fe may also interfere with manganese superoxide
dismutase and impair the initiation of apoptosis by the mitochondrion, rendering the cells
impervious to all the signals to undergo apoptosis from without and from within the cell.
Moreover, Fe may also play a crucial role on telomere repair, by activating telomerase.
Therefore, by inhibiting apoptosis and enhancing chromosome repair, Fe may bestow immortality
upon the cancer cell. Furthermore, Fe is one of the triggers for mitosis. Therefore, increased Fe
levels may be essential for the rapid growth characteristic of many malignancies. In turn, the rapid
growth further depletes resources from the healthy tissues, exacerbating the deficiencies of the
other elements and reducing the ability to fight the malignancy. Copyright 2001 Harcourt
Publishers Ltd.PMID: 11735307 [PubMed - indexed for MEDLINE]
poster:Jaynee
thread:103679
URL: http://www.dr-bob.org/babble/20020416/msgs/103913.html