This study investigated the effects of the intracarotid infusion of etoposide in combination with angiotensin II (AT II)-induced hypertension on the blood-brain barrier (BBB) and brain tissue in rats. Eighty rats were divided into five groups: Group 1, intravenous infusion of AT II to increase arterial blood pressure; Group 2, intracarotid infusion of etoposide at 22.5 mg/m2 for 10 minutes; Group 3, intracarotid infusion of etoposide at 75.0 mg/m2 for 10 minutes; Group 4, intracarotid infusion of etoposide at 75.0 mg/m2 for 20 minutes; Group 5, intracarotid infusion of etoposide at 75.0 mg/m2 for 10 minutes with AT II-induced hypertension. Evans blue staining of the brain was used as a monitor of BBB disruption. Mean arterial blood pressure over the experimental period in Group 1 increased from 86.3 +/- 1.3 mmHg (mean +/- SEM) to 139.0 +/- 2.4 mmHg, and Group 5 from 85.9 +/- 1.8 mmHg to 137.3 +/- 2.4 mmHg. None of the animals in Group 1 and 2 showed any obvious neurological change, while all the animals in Group 3, 4 and 5 exhibited diminished activity as their sole neurological change throughout the course of the experiment. Slight evidence of BBB disruption was seen in only 25% of the animals in Group 1. Significant BBB disruption was found in the animals in Group 2, 3, 4 and 5. No histological change was observed in any animal in Group 1 and 2.(ABSTRACT TRUNCATED AT 250 WORDS)