Electron microscopic study of ATPase activity in human brain tumors

Abstract

✓ Ultrastructural localization of ATPase was demonstrated in 15 human brain tumors; ATPase activity in the tumor cell was outside the cell membrane and appeared in varying degrees according to the type of tumor. Nonglial tumors such as meningiomas and chromophobe pituitary adenomas showed more intense enzyme activity than gliomas; malignant tumors such as medulloblastoma and glioblastoma multiforme showed low activity. Blood vessels in the tumor showed poor ATPase activity in both endothelium and basement membrane; the lack of ATPase in the vascular wall may contribute to the breakdown of the blood-brain barrier.