[Chemotherapy for experimental subarachnoid dissemination model of brain tumor]

Chemotherapy was applied for experimental subarachnoid dissemination model of brain tumor which was established in male Wister-SPF (SLC) rats inoculated intracisternally with 2 X 10(5) C6 rat glioma cells. Nontreated animals died about 24 days after inoculation. Autopsy findings of the animals showed localized or multifocal invasion of the tumor on leptomeninges in cisterna magna, and partially infiltration into the parenchyma of the cerebellum and medulla oblongata. Three days after inoculation, the tumor deposition and proliferation already occurred. Several tumor cell layers were found in the subarachnoid space over the cerebellomedullary surface. Tumor bearing animals were at first treated by single agent. These are ACNU administered intraperitoneally, methotrexate administered intracisternally, and OK-432 administered intraperitoneally. In the next stage, combination of these drugs was applied. ACNU, 3 mg/kg i. p., on Day 3, was effective in elongation of median survival time by 23.6%, statistically significant (P less than 0.02). Methotrexate, 0.25 mg/kg i.th., on Day 3, was also effective in elongation of median survival time by 8.4%, statistically significant (P less than 0.05). OK-432, 0.1 KE/kg i. p., daily, 14 times, from Day 3 to Day 16, was ineffective in elongation of median survival time. Combination of ACNU, methotrexate and OK-432, in the same schedule as described above, produced the longest median survival time of 42.4%, statistically significant (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)