The activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase in human cerebrospinal fluid

A method for the determination of cyclic nucleotide phosphatase (CNP) activity in cerebrospinal fluid is presented. In normal CSF the activity of CNP is very low. Comparing CSF from patients with multiple sclerosis to control CSF no significant difference is found, although a small proportion of MS patients has an elevated has an elevated CNP activity in their CSF. It is postulated that similar to other substances the CNP activity in CSF probably does not derive from the central nervous system.