Creatine uptake kinetics in brain and skeletal muscle of GAMT deficient knockout mice
Meeuwissen E, Veltien A, Isbrandt D, Kan H, Heerschap A
Radboud University Nijmegen Medical Center
In guanidinoacetate methyltransferase deficiency (GAMT-/-) creatine (Cr) concentrations in skeletal muscle and brain are severely reduced. We performed a detailed study of the Cr increase during Cr supplementation in a knockout mouse model of this disorder using 1H-MRS. Our results show that in GAMT-/- mice, Cr concentrations in skeletal muscle and brain increase in the course of days. Cr concentrations increase faster in skeletal muscle compared to brain, however, this is only apparent in the first week of supplementation. Regulation and expression of the Cr transporter in skeletal muscle and the blood-brain-barrier likely play a role in the observed differences.