Nuclear bodies produced in astrocytes by tilorone.

Large, eosinophilic, nonglycogenic nuclear inclusions were produced in the central nervous system by the drug tilorone. At the light microscope level, the inclusions occurred predominantly in astrocytes. Ultrastructurally, they were identical to the nuclear bodies described in many cell types under many conditions. The bodies were produced by tilorone in small numbers in the median eminence, a part of the hypothalamus that lacks a blood-brain barrier. They were produced in only 2 or 3 days in large numbers adjacent to zones of thermal or traumatic necrosis or in areas of inflammation. These facts, and the distribution of affected astrocytes, indicated that permeability factors and cerebrospinal fluid flow were involved in the development of the nuclear bodies. The large size and large number of nuclear bodies produced by tilorone should facilitate studies of this poorly understood nuclear organelle.