However, the DA catabolism process, reflected by the percentage of (DOPAC + HVA)/DA in the striatum of the PD rats, was accelerated by rasagiline but not by LLDT-8 administration (Fig. 4B), indicating that the mechanism of the dopaminergic neuroprotective effect of LLDT-8 in the PD model is very different from that of the MAO-B inhibitor, rasagiline. The gene discussed is MAOB; the disease is Parkinson disease.