Treatment with conduritol-β-
epoxide (CBE) in preclinical species is expected to be a powerful approach to generate animal models of
Gaucher disease (GD) and
Parkinson's disease associated with heterozygous mutations in
Glucocerebrosidase (GBA-PD). However, it is not fully elucidated how quantitatively the change in
glucosylsphingosine (
GlcSph) levels in cerebrospinal fluid (CSF) correlates with that in the brain, which is expected to be clinically informative. Herein, we aimed to investigate the correlation with successfully quantified
GlcSph in monkey CSF by developing highly sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. The
GlcSph in normal monkey CSF was 0.635 ± 0.177 pg/mL at baseline and increased by CBE treatment at 3 mg/kg daily for five days up to a moderate level, comparable to that in GD patients. The balance between
GlcSph and
galactosylsphingosine (GalSph) in the CSF matched that in the brain rather than plasma. In addition,
GlcSph in the CSF was increased, accompanied by that in the brain at a dose of 3 mg/kg daily. These results indicate that
GlcSph in the CSF is worth evaluating for concentration changes in the brain. Thus, this model can be useful for evaluating GBA-related diseases such as GD and GBA-PD.