A technique for simultaneous sampling of cerebrospinal and brain extracellular fluid in unanaesthetized rabbits

The continuous sampling of cerebrospinal fluid (CSF) from unanaesthetized rabbits was combined with dialysis-perfusion of the hippocampus in order to simultaneously sample the extracellular fluid (ECF) and the CSF. Implantation of the CSF-drainage into the subarachnoid space caused a transient increase of blood cells and serum-derived proteins in the CSF. Essentially normal values were restored within 4 days. The subsequent implantation of a dialysis probe also induced an increase in CSF cells and proteins which returned to preoperative values within 2 days. The protein pattern of the ECF was dominated by proteins with isoelectric points of 4.4, 4.5, 4.6 and 5.0 and molecular weights of 14, 30 and 45 kDa. Bands with similar mobility were seen in CSF and serum, however at relatively lower concentrations, as compared to the total protein content.