Changes in Myelin and Axonal Proteins in CaCl 2 -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.

Key Words:

Calcium–Ca²⁺-activated neutral proteinase–Ca²⁺-induced myelopathy–Neurofilament proteins–Myelin proteins.