Cyclodextrin nephrosis in the rat.

The renal toxicity of the Schardinger dextrins, alpha and beta-cyclodextrin, is manifested as a series of alterations in the vacuolar organelles of the proximal convoluted tubule. These changes begin as an increase of apical vacuoles and the appearance of giant lysosomes. The giant lysosomes characteristic of cyclodextrin nephrosis are notable because of the prominent acicular microcrystals embedded in the lysosomal matrix. Giant vacuoles devoid of acid phosphatase reaction product are found in advanced lesions. The vacuolar apparatus shows advanced changes prior to manifestation of lesions in mitochondria and other organelles. These observations indicate a role of the vacuologenic apparatus in the nephrotic process. Intracellular concentration of toxin via the lysosomal pathway represents a perversion of the physiologic function of the proximal tubule which ultimately leads to cell death.