Background: We investigated total electrolyte homeostasis in spinal cordcells of rats subjected to irreversible spinal cord trauma. Material/Methods: Forty-two rats underwenttotal transection of spinal cord (Group 1); chemical neurolysis by 10% lidocaine overdose (Group 2);sham "injury" (Group 3). Spinal cords were isolated 24 h, 72h or 7 days following injury. Total cellularCa, Mg, Na and K were measured in the spinal cord thoracic or lumbar parts using an atomic absorptionspectrometer. Results: Group 1: A significant Ca, Mg, Na, and K efflux was observed in thoracic and lumbarparts 24 h following transection. By 72h, a significant re-entrance of Ca was evident. By 168 h, an influxof all electrolytes was demonstrable, sometimes reaching concentrations above the pre-trauma levels.Group 2: Following 24 h, Na, K, Ca, and Mg concentrations dropped significantly both in thoracic andlumbar parts. By 72 h, the electrolyte re-entrance was evident in the thoracic, but not the lumbar part.By 168 h, Na, K, Ca, and Mg influx was observed both in thoracic and lumbar parts, the concentrationapproaching pre-trauma levels. Group 3: No changes in electrolyte content were observed in spinal cordsof sham-operated animals. Conclusions: Following massive, apparently irreversible injury of the spinalcord, some restorative processes do take place at the cellular level. Subsequent supernormal accumulationof intracellular electrolytes, especially Ca, might eventually contribute to a secondary injury. Shouldthis be the case, pharmacotherapeutic intervention might prove beneficial.

Keywords: Calcium - metabolism, Electrolytes - metabolism, Intracellular Fluid - metabolism, Ion Transport, Magnesium - metabolism, Potassium - metabolism, Sodium - metabolism, Spinal Cord Injuries - metabolism