Lysosomes are the main component of an intracellular digestive system which has
been recognized in a wide variety of cells, both in plants and animals. They were first
discovered in rat livers, by do Duve et al. (1955), through biochemical studies that
revealed the existence of a distinct group of cytoplasmic particles, surrounded by a
membrane, and containing acid hydrolases.
Lysosomes are important in cellular pathology because they are almost invariably
involved in the response of the organism to the challenging agents and because the
lysosomal reaction often becomes an important contributing pathogenic factor as well as
a component of the symptomatology.
Lysosomes may also mediate tissue damage by releasing their enzymes directly into
the cell sap or surrounding tissues. Such an effect was observed following the addition
of excess vitamin A to fetal bone rudiments in organ culture(Fell and Thomas, 1960;
Thomas et al., 1960; Dingle, 1963).
The exact mechanism of the effect of excess vitamin A on the membranes of
lysosomes is still controversial. The mechanism of intracytoplasmic release of lysosomal
hydrolases facilitated by the action of vitamin A is thought to be either rupture of the
lysosomal membrane(Dingle and Fell, 1961 ; Weissmann et al., 1963; do Duve, 1963;
Roels et al., 1969), or leakage across the lysosomal membrane (Schin and Cleven, 1965;
Trump et al., 1965; Weissmann, 1965; Comolli, 1967; Friedman et al., 1969).
The purpose of the present study is to determine the effect of excess vitamin A to
the lysosomal membrane and the stabilize effect of cortisone.
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