[Stereotaxic vascular morphology in experimental gliomas and its relationship with normal vascularization in the developmental stage].

Three-dimensional vascular architecture of the experimental gliomas produced in adult nude mice by intracerebral inoculation of rat glioma C-6 cells (Benda et al., 1968) was studied through a scanning electron-microscope using the vascular casting method (Yoshida & Ikuta, 1981), and compared with that of developing rat cerebellums. It was observed that smoothly running blood vessels of identical diameter in the surrounding non-neoplastic nervous tissue were connected with extremely dilated and tortuous ones at the border of the neoplasm. In addition to the increased number of these branches, the vascular architecture in the glioma demonstrated characteristic nodular protrusions, or small ring-like anastomoses. Within the lumina, septum-like formations were formed. On the other hand, it was found that surprisingly similar vascular features were observed in the subarachnoid space of the developing external granular cell layer from birth until approximately 2 day after birth in the rat cerebellum. Then, after 4 days from birth, these features disappeared and resulted in numerous small vascular proliferations. The present study strongly suggests that the newly formed vessels in the gliomas are definitely "abnormal" compared with the vessels of normal adult animals, but that the process of vascularization in the glioma is based on the way of vascularization noticed in normal developing fetal and newborn brains.