Fine structure of contrasting choroid plexus lesions caused by tertiary amines or cyclophosphamide.

Hydropic alterations of the fine structure of the choroid plexus epithelium following administration of three different tertiary amines to rats were compared with alterations produced by cyclophosphamide and with normal choroid plexus. Single doses of 2,7-bis(2-diethylamino)-ethoxy)-4-methyl-1,8-naphthyridine HCl or 2,6-di-(omega-dimethyl aminoethoxy)-pyridine produced dramatic accumulations of membrane-limited vacuoles. Multiple doses of 2,7-bis-(diethylaminoethoxy)fluoren-9-one HCl (tilorone) produced accumulations of dense cytoplasmic bodies in choroid epithelial cells in addition to the hydropic vacuoles. Differential responses to these agents suggested functional specialization or temporal variation in function among adjacent choroidal cells. Despite the occurrence of pronounced plasma exudation in the plexitis following cyclophosphamide treatment, there was no hydropic vacuolization.