5'-Nucleotidase activity in human astrocytomas.

Human astrocytomas contain 5'-nucleotidase as shown using histochemical, cytochemical and biochemical techniques. 5'-Nucleotidase activity was revealed by electron microscopy to be associated with the outer surface of the plasma membrane of astrocytoma cells. The results confirm and extend previous reports of the localisation of 5'-nucleotidase in normal astrocytes in situ. Biochemical assay of 5'-nucleotidase activity in 35 tumours showed it to be clearly higher in malignant (anaplastic astrocytomas and glioblastomas) than in benign astrocytomas.