AVAILABLE evidence suggests that normal brain tissue will not survive a period of total, temporary ischemia exceeding five to seven minutes.1,2 The vulnerability of neoplasms arising from glial cells or other intracranial structures to temporary ischemia has not been extensively evaluated inasmuch as it has been difficult selectively to deprive tumor tissues of blood and then restore circulation at a precise moment. This study was conducted with an experimentally produced glioma in C3H mice which is readily accepted in subcutaneous transplantation by other animals of the strain.
Materials and Methods
This tumor, an ependymoma, was originally induced by intracerebral implantation of methylcholanthrene after the method of Zimmerman3 by Dr. Dogan Perese of the Roswell Park Institute, Buffalo, New York, who supplied it to this laboratory. It has grown well in subsequent transplantations with no significant change in its histologic picture. For transplantation, a suspension of tumor cells was