Neuropeptides seem to play an important role when the central nervous system is challenged. In order to obtain better insights into the central peptidergic effects, it is essential to monitor their concentration in the brain. Quantification of neuropeptides in dialysates is challenging due to their low extracellular concentrations (low pM range), their low microdialysis efficiencies, the need for acceptable temporal resolution, the small sample volumes, the complexity of the matrix and the tendency of peptides to stick to glass and polymeric materials. The quantification of neuropeptides in dialysates therefore necessitates the use of optimized, sensitive nanoUPLC–MS/MS methods. For this purpose, the effect of superchargers is assessed on peptide signals. In addition, microdialysis parameters need to be optimized to achieve maximal peptide recovery. This project focuses on the peptides of the neuromedin group, more specific neuromedin U.
In addition to nanoUPLC-MS/MS, we examine the in vitro stability of synthetic peptides in human plasma via HPLC-UV in a collaboration with Department of Organic Chemistry of the VUB.