Abstract
It is a well-known fact that damage to a cell induces activation of lysosomes. This phenomenon subsequently leads to “autofagy” and “heterofagy, ” which are typical functions of lysosomal enzymes. Some reports state that lysosomal enzymes are highly activated also during cellular division and multiplication. Furthermore, it has been verified that the enzymes retain by far a higher activity in malignant tumor cells. A recent report indicated that cyclic AMP supports morphologically cultured glial cells and glioma tissues toward their differentiation and further toward normalization.
Based on these reports, it was the object of this study to examine the effect of cyclic AMP on lysosomal enzyme activities during cellular multiplication. In the acute stage, within one week from injury infliction, β-glucuronidase and acid-phosphatase increased activities conspicuously and reached their respective peaks on the 5th day after injury. The glial cell, being induced by the high enzyme activity, showed active cellular division and multiplication starting from the 5th day on. Although elevation of activity was clearly observed at this stage, the enzyme activity showed little difference during the period of gliosis formation, when division and multiplication settled. Human glioma tissues retained a level of activity several times higher. Administration of dibutyryl cyclic AMP in situ produced significant inhibitory tendency on the enzyme activity, resulting in impediment of multiplication.
The rise in enzyme activity after cellular damage and along with cellular division were directly reflected in the cerebrospinal fluid, which might be utilized in diagnosing the extent of intracranial disorders, effectiveness of treatment and prognosis.
