Increased cerebrospinal fluid concentrations of C- but not N-terminal cholecystokinin fragments in multiple sclerosis

The sulfated N-terminus and the carboxyamidated C-terminus of cholecystokinin octapeptide (CCK-8) were radioimmunoassayed in cerebrospinal fluid from 19 patients with multiple sclerosis (MS) and 17 control subjects. While the N-terminal immunoreactivity was normal in all phases of MS, the concentration of C-terminal CCK immunoreactivity was significantly increased from 3.7 +/- 0.3 to 7.9 +/- 1.0 pmol/l (mean +/- S.E.M.) in both progressive and stable phases. The results indicate that C-terminal forms of CCK are released at an increased rate or that increased amounts of CCK-8 are released together with enhanced aminopeptidase activity in MS.