Microdialysis of galanin in rat spinal cord: in vitro and in vivo studies.

The release of the neuropeptide galanin was measured with microdialysis in the dorsal horn of the rat spinal cord. Recovery of unlabeled galanin-like immunoreactivity (GAL-LI) in vitro was measured with radioimmunoassay (RIA) and was found to be 1.4-1.5%. In vivo galanin level was close to the detection level of the RIA under basal conditions. The peptide was released in the dorsal horn during electrical stimulation of the sciatic nerve. The nerve was stimulated for 30 min at a stimulus strength that activated A- and C-fibers. Thus, release of galanin in the spinal cord of the rat is possible to measure with the microdialysis technique.