Daniel Guo Quae Chong1, Jean-Marc Nuoffer2, Peter Vermathen1, Johannes Slotboom3, Chris Boesch1, Roland Kreis1
1Department of Clinical Research, University of Bern, Bern, Switzerland; 2Metabolic Unit, Inselspital, Bern, Switzerland; 3Neuroradiology, Inselspital, Bern, Switzerland
Histidine transport across the blood brain barrier (BBB) is investigated using 1H-MRS. Volunteers consume a single high dose of His causing blood His levels to peak at 30 times normal in 1-3 hours. Brain His levels peak ~4 hours after blood His. Blood His shows individual absorption and disposal rates for different subjects, while brain His suggest saturation of His influx across the BBB. Blood His and brain His appear to be linked in each subject. Evaluation of the time series of spectra was performed by simultaneous fitting with prior knowledge constraints.