N-terminally extended tachykinins in human cerebrospinal fluid.

With HPLC-RIA methods we were unable to demonstrate SP and NKA in measurable amounts in human CSF. Instead N-terminally extended forms of these peptides were found to be present and could be quantitated. The finding that these forms of tachykinins can be released from nervous tissue might suggest that their levels in CSF can be used as markers of the activity in central SP and NKA neurons.