1982 Volume 136 Issue 2 Pages 219-229
TAKADA, G., ONODERA, H. and TADA, K. Delivery of Fungal β-Galactosidase to Rat Brain by Means of Liposomes. Tohoku J. exp. Med., 1982, 136 (2), 219-229-A significant increase in β-galactosidase activity was observed in the brain of rats 1hr after an intravenous injection of liposomes containing β-galactosidase purified from Aspergillus oryzae. The increased activity was proved to have features of the fungal enzyme by differentiating it from rat's native β-galactosidase in both heat stability and immunochemical studies. Blood content of rat brain tissue under the experimental conditions employed was estimated as 0.83% (v/w) from an infusion experiment of 131I-labeled human serum albumin. The net uptake of fungal β-galactosidase by rat brain was calculated as equal to 10μg protein of the fungal enzyme or 0.31% of the injected dose/g tissue, which gave rise to 4.4-fold net increase in enzyme activity above control levels. The experiments clearly demonstrated that liposome-entrapped fungal enzyme was allowed to penetrate the blood-brain barrier and to gain access to rat brain, suggesting liposomes as an effective carrier for exogenous enzyme delivering to the central nervous system of patient with inherited lysosomal storage diseases.
