Changes in myelin and axonal proteins in CaCl2-induced myelopathy in rat spinal cord.

Calcium-induced myelopathy was produced in rats by dripping 1.0 ml of a 10% solution of CaCl2 at pH 7.4 upon exposed spinal cord. Changes in spinal cord proteins were examined following application of calcium. Analysis of proteins by SDS-PAGE revealed progressive losses of neurofilament, microtubular, and glial filament proteins over a period of 8 hours to 5 days. Large losses of myelin proteins were also evident. The protein alterations observed correlate well with ultrastructural changes and resemble those previously found with physical trauma. These observations indicate that Ca2+ plays a pivotal role, possibly by activating proteinase(s), in the degeneration of axons and myelin sheath in both Ca2+-induced myelopathy and spinal cord injury.