Tissue calcium levels in CaCl2-induced myelopathy

CaCl2-induced myelopathy was produced in rats by the application of a solution of CaCl2 to exposed leptomeninges of lumbosacral spinal cord. Equal lengths of remote cervical and lumbar cord were removed at intervals following Ca2+ application. The total Ca2+ in tissue from lumbar cord was significantly elevated over autologous cervical cord and homologous lumber controls after after 2 h. The maximum Ca2+ increase in lumbar cord was 3.9-fold that of homogolous control and was reached by 8 h post Ca2+ application. The time course for the elevation of Ca2+ as measured by atomic absorption spectrophotometry, resembles that found in spinal cord following direct physical trauma. These findings as well as similar changes in morphology and neural proteins from previous studies suggest that Ca2+ is involved in and may potentiate the degeneration of axons and myelin via Ca2+-activated neutral proteinases.