Liposomes as Carriers <i>in vivo</i> for Methotrexate

Abstract

In differential activation, advantage is taken of the different sensitivity of the various organelles towards digitonin which is added in uitro to liver homogenates (HuybrechtsGodin & Jacques, 1974). The method can be applied to the localization of exogenous material without parallel treatment by ancillary lysosomotropic compounds. Table 2 illustrates the digitonin-induced release of latent marker enzymes characterizing several cytoplasmic organelles or substructures, and of two drugs utilized in applied lysosomology : horse-radish peroxidase and suramin. The totality of the intracellular drug could be found within cytoplasmic vacuoles representing either lysosomes, or vesicles deriving from the plasma membrane (heterophagosomes?) or both types of structures, in a tissue whose molecular and cellular dynamics cannot possibly have been altered by the ancillary lysosomotropic compounds required for the centrifugation technique. In addition, these results allow us to discard the hypotheses that, in our experimental conditions, a measurable proportion of any of the two drugs might have concentrated within Golgi structures, the lumen of endoplasmic reticulum or the interstitial compartments of mitochondria. Huybrechts-Godin, G. &Jacques, P. J. (1974) Arch. Int. Physiol. Biochim. in the press Jacques, P. J. (1968) Epuration plasmatique de protiines dtrangt?res, leur capture et leur destinie Jacques, P. J. (1972) in Uptake of Informative Molecules by Living Cells (Ledoux, L., ed.), Jacques, P. J. (1973) in International Aspects of Drug Evaluation and Usage (Jouhar, A. J. & Jacques, P. J. (1974) in Methodological Developments in Biochemistry (Reid, E., ed.), vol. 4, dam l'appareil vacuolaire du foie, Librairie Universitaire, Louvain pp. 277-294, North-Holland, Amsterdam Grayson, M. F., eds.), pp. 347-352, Churchill-Livingstone, London pp. 415-420, Longman, London