Catalase-positive particles (“microperoxisomes”) from rat preputial gland and bovine adrenal cortex

Catalase activity was detected histochemically within membrane-bound cell organelles in epithelial cells of rat preputial gland and bovine adrenal cortex. These particles are oval to worm-like in rat preputial gland, 0.08 – 0.15 μm thick and up to 1.0 μm long. In bovine adrenal cortex the shape of catalase-positive particles is rather spherical (diameter 0.1 to 0.3 μm). Particles of both organs lack crystalline or dense cores.Biochemical examination of cell fractions prepared from tissue homogenates by differential centrifugation revealed the presence of two typical peroxisomal oxidases, viz. α-hydroxy acid and -amino acid oxidase, with maximal relative specific activities in the ‘microsomal’ fraction (preputial gland) and in the ‘lysosomal’ fraction (adrenal cortex), respectively. Urate oxidase is absent in both tissues.The concomitant occurrence of catalase and hydrogen peroxide producing oxidases in the particles described characterizes them as true peroxisomal systems (‘microperoxisomes’).