The effect of hypervolemic hemodilution or hypervolemic hemodilution with dopamine-induced hypertension on cerebral blood flow (CBF) was investigated during 1.2 MAC isoflurane anesthesia in rats (n = 24) subjected to middle cerebral artery occlusion (MCAO). Prior to MCAO each animal was randomized to one of the following groups: 1) control, mean arterial pressure (89 +/- 10 mmHg [mean +/- SD]), blood volume, and hematocrit (46 +/- 1) were not manipulated; 2) hypervolemic hemodilution (HH), 30 min before MCAO, 5% albumin was administered to reduce the hematocrit to 29-32%; or 3) hypervolemic hemodilution/dopamine hypertension (HH/Dop), hemodilution was accomplished and dopamine (10 micrograms.kg-1.min-1) was infused during the ischemic period to achieve a mean arterial pressure of 111 +/- 10 mmHg (mean +/- SD). Ten minutes after occlusion of the left middle cerebral artery, CBF was determined using 14C-iodoantipyrine. Five coronal brain sections were analyzed to determine the area within each brain section with CBF ranges of 0-15 ml.100 g-1.min-1 and 15-23 ml.100 g-1.min-1. The area of 0-15 ml.100 g-1.min-1 CBF was less in both the HH and HH/Dop groups compared with control (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)