THE PRESENCE OF A MANGANESE-RICH PARTICLE IN LYSOSOME OF RAT PANCREASDUE TO EXCESS MANGANESE TREATMENT

Manganese (Mn) accumulates at a higher level in the pancreas than in a ny other organs when excess Mn is administered to the rat. The present study is carried out to analyze the intracellular localization of Mn existed in the pancreatic cell of Mn-treated rats. Transmission electr on microscope and X-ray micro-analysis connected with a rapid freezing fixation technique showed that a large amount of Mn was localized in lysosomal particles of the pancreatic cell of Mn-treated rats. The Mn- rich particles disappeared when the element-administration was discont inued, showing that the accumulation of Mn is reversible. To confirm t hat Mn is in the lysosomes, a centrifugal subcellular-fractionation an d a neutron activation analysis were carried out. The result indicated that much Mn existed in the lysosomal fraction.