Quantitative analysis of iron concentration and expression of ferroportin 1 in the cortex and hippocampus of rats induced by cerebral ischemia.

Iron overload induced by brain ischemia has been shown to be involved in neurodegenerative disease. Little is known about the relationship between brain ischemia and ferroportin 1 (FP1). The aims of this study are: (i) to determine whether iron accumulation in the brain is induced by cerebral hypoperfusion; and (ii) to test whether expression of FP1 is influenced by cerebral ischemia. The common carotid arteries (CCA) of rats were ligated bilaterally to induce cerebral ischemia, and the iron concentration of the cortex and hippocampus was measured by graphite furnace atomic absorption spectrometry. Iron was stained by Perl's method. The expression of FP1 mRNA and protein was shown by the reverse transcriptase polymerase chain reaction and immunohistochemical methods. The iron concentration in the cortex and hippocampus of ischemic rats had increased on day 7 (CCA7) and significantly on day 28 (CCA28) compared to control rats. More iron granules had been deposited in the cerebral cortex and hippocampus in rats with bilaterally ligated CCA on CCA7 and CCA28. In ischemic rats, FP1 expression in the cerebral cortex and hippocampus was decreased by CCA7 and this was more marked by CCA28 compared to control rats. We therefore concluded that iron deposition in the cerebral cortex and hippocampus of rats is induced by cerebral ischemia. Iron deposition may be attributed to the decrease in FP1 expression, and this inhibition of FP1 expression could be a major contributor to the formation of iron deposits in cerebral ischemia.