Total cell associated electrolyte homeostasis in rat spinal cord cells following apparently irreversible injury.
Michael Chanimov, Sylvia Berman, Vladislav Gofman, Yehoshua Weissgarten, Zhan Averbukh, Mathias Cohen, Alexander Vitin, Murat Bahar
Med Sci Monit 2006; 12(2): 63-67
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: Homeostasis, Electrolytes - metabolism, Calcium - metabolism, Animals, Intracellular Fluid - metabolism, Ion Transport, Magnesium - metabolism, Male, Potassium - metabolism, Rats, Rats, Sprague-Dawley, Sodium - metabolism, Spinal Cord Injuries - metabolism