HILIC-MS Rat Brain Analysis, A New Approach for the Study of Ischemic Attack.

Clinicians often rely on selected small molecular compounds from body fluids for the detection, screening or monitoring of numerous life-threatening diseases. Among others, important monoamines - biogenic amines (BAs) - and their metabolites serve as sensitive biomarkers to study the progression or even early detection of on-going brain pathologies or tumors of neuroendocrine origins. Undertaking the task to optimize a reliable method for the simultaneous analysis of the most relevant BAs in biological matrices is of utmost importance for scientists. Hydrophilic interaction liquid chromatography (HILIC) with mass spectrometry (MS) detection provides a specific and sensitive technique for the separation and assessment of several neurotransmitter concentrations in body fluids (blood, urine, tissues). The present study was focused on the optimization of a straightforward, sensitive and reliable method for the simultaneous analysis of the ten most important BAs and their acidic metabolites from homogenates of rat brain tissues by use of HILIC-MS. Here, we present the optimized experimental workflow in terms of sample preparation, buffer compositions, HILIC and MS settings and data analysis. The presented method is reliable, straightforward and sensitive. Our method permits the unbiased, qualitative and quantitative determination of several BAs and their metabolites simultaneously. The optimized method was applied to the analysis of rat brain tissue samples from healthy hemispheres or those with induced transient ischemic attack (TIA). The undertaken pilot study demonstrated that the proposed approach could be applied to reveal the perturbation in neurotransmitters concentration after TIA in rat brains.