Enolase isoenzyme distribution in the human brain and its tumours

Abstract

Using the immunoperoxidase PAP method we have studied the cellular distribution of α, β and γ enolase subtypes in normal human adult brain and in human brain neoplasms. γ enolase is found only in viable neurones throughout the brain. α enolase is demonstrable in astrocytes, ependymal cells, capillary endothelial cells, Schwann cells and arachnoidal endothelial cells but oligodendrocytes appear to have low levels of this isoenzyme. β enolase is not demonstrable in normal brain tissues. Of the primary cerebral neoplasm studied only medullo-blastomas and neuroblastomas did not contain demonstrable enolase. Astrocytomas, ependymomas, oligodendrocytomas, meningiomas and acoustic neuromas all contained varying quantities of α enolase. No cerebral tumours contained β or γ enolase. Tumour and adjacent brain tissue with histological evidence of ischaemia and necrosis showed loss of cellular enolase.