POSTISCHEMIC REPERFUSION CAUSES A MASSIVE CALCIUM OVERLOAD IN THE MYELINATED SPINAL-CORD FIBERS

The visualization of Ca binding in the myelinated axons of lumbosacral segments of rabbit was done at the electron microscopic level using t he spinal cord ischemia model. To assess the calcium accumulation, the binding agent pyroantimonate was used. Nonsignificant Ca2+ binding wa s found in the myelinated axons after 40 min of ischemia followed imme diately by perfusion fixation. A high concentration of calcium pyroant imonate deposits, seen as electron dense particles, was detected in th e myelin interlamellar clefts and axoplasm. The paranodal region was t he most affected site.