[Cell to cell transfer of dense bodies induced by intracisternal infusion of leupeptin in rat cerebellum--quantitative and ultrastructural studies].

ABSTRACT

Previous studies have demonstrated that rats treated with a proteinase inhibitor, leupeptin (Leu), show an accumulation of lipofuscin (Lf)-like dense bodies in the neurons. The present study examines the quantitative and ultrastructural changes in the Lf-like dense bodies of Purkinje (P) cells and Bergmann (B) glia over 20 days following a 4-day regimen of Leu administration by intracisternal infusion. Toluidine blue staining revealed considerable Lf-like granules in both types of cells 1 day after Leu infusion. However, these granules had almost disappeared by 20 days after infusion. Quantitative analysis revealed a decrease in the amount of accumulated Lf-like granules in P cells whereas the granules in B glia increased 10 days after Leu infusion. Electron microscopic examination revealed the presence of Lf-like dense bodies on the plasma membranes of both the P cells and B glia. The present results suggest that Leu-induced dense bodies in P cells are transferred to B glia, indicating a possible route for the removal of Lf.