[Experimental studies on induced hypertension chemotherapy of intracerebral inoculated gliomas in rats].

Blood flow of transplanted intracerebral rat gliomas was measured before and after a constant I.V. infusion of angiotensin II-induced arterial hypertension using hydrogen clearance method. The brain tumor model was produced in syngeneic Wistar-King-Aptekman male rats by stereotaxic inoculation of ethylnitrosourea-induced glioma cells (KEG-1). Induced hypertension by angiotensin II infusion resulted in a significant increase in tumor blood flow compared with control levels (P less than 0.001). In addition, the therapeutic effect of administration of 3-[(4-amino-2-methyl-5-pyrimidinyl) ethyl] -1-(2-chloroethyl)-1-nitrosourea (ACNU) during angiotensin II-induced hypertension was evaluated. At 12 days after implantation, tumor-bearing rats were administrated angiotensin II as the mean blood pressure reached 150 mmHg, followed by ACNU injection, maintained the same blood pressure for 20 minutes. ACNU with induced hypertension group showed a median survival time of 27.0 days, which was significantly (P less than 0.02) longer than that of ACNU alone (22.0 days). It is therefore suggested that chemotherapy with angiotensin II-induced hypertension has a enhancing effect on chemotherapy for improving the drug delivery to tumor tissue by a increased tumor blood flow.