Unusual cytoplasmic bodies in Purkinje cells of the Gunn rats.

The fine structural changes of cerebellar Purkinje cells in Gunn rats were studied with electron microscope to clarify the neurotoxicity of bilirubin. The previous reports including mitochondrial change were confirmed. The new cytologic feature demonstrated in this study was the presence of two different types of unusual membranous cytoplasmic bodies (MCB). One type was the aggregation of rod-like structures which were enveloped in double membranes and contained homogeneous and electron-dense matrix. Another type was the whirled lamellar structure which appeared to be formed of the microtubules and its unit particles. These two different MCB may suggest the different neurotoxicity of bilirubin: the former may result from the accumulation product of bilirubin-lipid complex, the latter may reflect the abnormal process of the microtubular assembly induced by bilirubin.