Ultrastructural effects of Conray 60 and Pantopaque on ependyma and choroid plexus following intraventricular injections.

Electron microscope evaluation of choroid plexus and ependyma following single cerebral intraventricular injections of Conray 60 and Pantopaque was carried out on 35 rats and 4 dogs. The animals were sacrificed at periods ranging from 1 hour to 4 months. Conray was not detected with the light or electron microscope; however, Pantopaque was presumptively localized as electron-dense masses associated with lipid-like bodies at the ventricular interface of both choroidal and ependymal epithelium. Conray 60 injections consistently induced convulsions in rats. Histological studies demonstrated moderate cellular damage and multilayered proliferation of ependymal epithelium. Morphological damage following Pantopaque was more severe and widespread in both choroid plexus and ependyma suggesting that, of the two agents, Conray may have the greater clinical potential provided that the associated convulsions are controlled by appropriate measures.