GPT and Parkinson disease: In PD patients there are reports of decreased CSF post-proline cleaving enzyme (Hagihara and Nagatsu, 1987), increased dipeptidyl-aminopeptidase II (Hagihara et al., 1987), normal dipeptidyl-aminopeptidase IV (Hagihara et al., 1987), and normal glutamic oxaloacetic transaminase (GOT) (Steen and Thomas, 1962; Weiss et al., 1975; Qureshi et al., 1995) and glutamic pyruvic transaminase (GPT) (Weiss et al., 1975) levels.