Decreased plasmatic spermidine and increased spermine in mild cognitive impairment and Alzheimer's disease patients

Abstract Background Current evidence suggests that upregulation of polyamines system plays a role both in cognitive deficit and synaptic loss observed in Alzheimer's disease (AD). Objective The aim of this study was to determine the plasmatic concentration of polyamines in mild cognitive impairment (MCI) and AD patients in comparison with healthy controls (HC). Methods Plasmatic polyamines were quantified using the AbsoluteIDQ® p180 and liquid chromatography coupled to tandem mass spectrometry (LC/MS-MS). Results The study group comprised 34 AD patients, 20 MCI and 25 HC. All individuals were followed for 4 years. During this period 8 amnestic MCI patients (40% of the MCI sample at baseline) converted to AD. Spermidine level was lower in both patient groups (AD; MCI) compared to HC (p = 0.007). Plasma levels of spermine were higher in the MCI group (p < 0.001), but decreased in the sub-sample of MCI patients who converted to AD (p = 0.043). No statistically significant differences were found in ornithine and putrescine levels (p = 0.056 and p = 0.126, respectively). Discussion Our results suggest dynamic changes in the expression of polyamines in the MCI-AD continuum.

Plasma 1,3-diaminopropane, putrescine and their conjugates in normal and schizophrenic subjects

The levels of free and conjugated 1, 3-diaminopropane and putrescine in human plasma of normal and schizophrenics, are determined by initial purification using cation exchange resin followed by paper chromatography and/or enzymatic analysis. 1, 3-Diaminopropane, putrescine and their conjugates are found in the plasma of schizophrenic patients in concentration higher than in the plasma of normal subjects. The difference between the diamine [free and conjugated] concentrations of normal and schizophrenic subjects were found to be statistically significant