Micro Autoradiographic Study on the Tissue Localization of Liposomeentrapped or Unentrapped ³H-β-Galactosidase Injected into Rats

Abstract

The localization of intravenously injected liposome-entrapped or unentrapped ³H-β-galactosidase in various tissues of rats was studied by microautoradiography. The appearance of microautoradiographic silver grains, that is, the uptake of the ³H-enzyme was observed in all of the tissues studied, such as the liver, kidneys, spleen, lungs, heart, muscle and brain from both groups of rats. The most active organ in taking up both forms of the ³H-enzyme was the liver, where Kupffer cells were supposed to be most responsivle for it. The uptake of both forms of the enzyme was also observed in the brain, which indicate that the administered enzyme could pass through the blood-brain barrier. Moreover, the uptake of the ³H-enzyme in the brain was revealed to be greater in the gray matter than in the white matter. The possibility of the enzyme replacement therapy towards the lysosomal storage diseases involving the central nervous system was suggested.