Calcium-induced degeneration of the cytoskeleton in monkey and human peripheral nerves

Biopsy specimens of human and monkey peripheral nerves, when incubated in calcium containing media, showed a loss of neurofilaments and microtubules with replacement by granular debris. Cytoskeletal structures remained intact when incubated in calcium-free media. Disruption of neurofilaments and microtubules in calcium containing media was inhibited by the thiol protease inhibitor, leupeptin. Similar incubations of excised Pacinian corpuscles revealed evidence of early terminal axon degeneration in the presence of calcium. These data substantiate the hypothesis that neural cytoskeletal degradation in primates and in man is calcium-mediated.