CAT and Parkinson disease: Some authors described decreased activities of the antioxidant enzymes glutathione-peroxidase (GPx) [37,38], total superoxide-dismutase (SOD) [39], Mn-SOD [40], Cu,Zn-SOD [41], and catalase [37], in the substantia nigra of PD patients; while Mn-SOD activity in the cortex of PD patients has been found increased [35,42].