Cerebral lysosomes. VI. The in vivo uptake of triton-WR-1339 by the lysosomes of the immature cerebral cortex and cerebellum.

A number of recent reviews on neural lysosomes6, 8-10 have stressed the difficulties intrinsic to the isolation of these organelles in pure form from homogenates of brain tissue. We believe that this is a direct reflection of the remarkable lysosomal heterogeneity 13 of brain, which, in turn, derives from the complex mosaic of functional specificities exhibited by this organ. In two recent publications, we described the preparation of partially purified lysosomal fractions from several neuroanatomical areas of the rat brain 16 and presented comparative data relating the in vitro stability of lysosomes isolated from immature and adult brain cortex, thalamus and hypothalamus toward certain ionic and osmotic factors 17. In this paper we describe the in vivo uptake of Triton-WR-1339 (ref. 20) by the lysosomes of the brain cortex and the cerebellum of the immature rat and the effects of this functional event on their centrifugal properties. A preliminary account of some of the findings has appeared 18.