The role of iron in Parkinson's disease monkeys assessed by susceptibility weighted imaging and inductively coupled plasma mass spectrometry

Mounting evidences indicated that elevated iron levels in the substantia nigra (SN) have been concerned as the underlying mechanisms of neurodegenerative diseases, including Parkinson's disease (PD). The present study used the 1-Methyl-4-phenyl-1, 2, 3, 6 -tetrahydropyridine (MPTP)-treated cynomolgus monkeys for PD to evaluate the usability of SWI for assessing iron deposition in the cerebral nuclei of PD. The results showed that susceptibility-weighted imaging (SWI) phase values of the ipsilateral (MPTP-lesion side) SN of MPTP-treated monkeys were lower than those in the contralateral SN of MPTP-treated monkeys and the same side of Control monkeys, suggesting that iron deposition were elevated in the affected side SN of MPTP-treated monkeys. Whereas MPTP has not effects on the SWI phase values in other detected brain regions of monkeys, including red nucleus (RN), putamen (PUT) and caudate nucleus (CA). Furthermore, ICP-MS results showed that MPTP increased the iron levels in MPTP injection side, but no in the ipsilateral striatum. Additionally, MPTP treatment did not affect the calcium and manganese levels in the detected brain regions of monkeys. However, Pearson correlation analysis results indicated that there were not relationship between SWI phase values in MPTP-lesion side of SN with the behavioral score, tyrosine hydroxylase (TH)-positive cells number and iron levels in the MPTP-lesion side of midbrain. Taken together, the results confirm the involvement of SN iron accumulations in the MPTP-treated monkey models for PD, and indirectly verify the usability of SWI for the measurement of iron deposition in the cerebral nuclei of PD.