The effects of cadmium chloride on organotypic cultures of rat sensory ganglia

Abstract Organized cultures of rat dorsal root ganglia were subjected to 4 × 10 −4 M cadmium chloride for periods of time ranging between 1 and 21 days. Light microscopic studies carried out on semi-thin sections revealed dark masses which were stained with PAS in the periphery of neuronal perikarya. These deposits increased in size with increasing exposure to Cd ++ . At the ultrastructural level, these regions corresponded to large aggregates of glycogen. The accumulated polysaccharide was not surrounded by a membrane, but was quite clearly demarcated from the rest of the cytoplasm. Numerous nerve cells contained unifocal deposits of compact whorls of 100–120 A filaments. Filamentous spheroids often became so voluminous as to fill the entire diameters of neuronal perikarya. This process resulted in a shift of the pyrenophore toward an eccentric position. In other nerve cells, sizeable lipid drops, measuring 2 μ in diameter, were found. In their vicinity, numerous profiles of altered mitochondria occurred, which often contained exceptionally large matrix granules. In spindle-shaped distensions of unmyelinated axons, a variety of degenerating mitochondria and myelin figures were located. Other axis cylinders contained glycogen particles randomly distributed, or increased filaments in a predominantly longitudinal orientation. From the present study it is obvious that Cd ions are capable of inducing pathological changes in peripheral nervous tissue directly, apart from damaging the endothelium of blood vessels.