Influence of age on the development of cadmium-induced vascular lesions in rat sensory ganglia.

It is known from previous investigations that parenteral administration of single large doses of cadmium salts causes hemorrhagic lesions in the sensory ganglia of adult rats, whereas the ganglia of immature rats remain unaffected. The present study was undertaken to determine more precisely the age at which vascular lesions occur in the sensory ganglia of rats. At the age of 10 days, thrombocytes accumulated and adhered to the endothelial cells in vessels of the trigeminal ganglion, and at the age of 12 days focal hemorrhages occurred in the vicinity of nerve cells. After the age of 12 days, ultrastructural changes in endothelial cells were present in the trigeminal ganglia, with condensation of the cytoplasm, nuclear pyknosis, and discontinuities of the endothelial lining. Intravascular thrombus formation was also observed. In the dorsal root ganglia, there were no hemorrhages before the age of 22 days. The vascular lesions were then similar to those in the trigeminal ganglia. The possible relation between the structure and permeability of endothelial cells and the development of hemorrhagic lesions is discussed.