Sequential changes in cerebrovascular reserve capacity in three-vessel occlusion rats.

To understand the pathophysiology of hemodynamic compromise, we evaluated the cerebrovascular reserve capacity of a cerebral hemisphere in rats with 3-vessel occlusion (3VO). The bilateral vertebral and left common carotid arteries were occluded in Wistar rats. Sequential changes in local cerebral blood flow (LCBF) and local cerebral plasma volume (LCPV) were measured by [14C]iodoantipyrine and [14C]dextran autoradiography, respectively. There was no significant difference in LCBF between 3VO and control rats at rest. After acetazolamide administration, however, an increase of LCBF in the left hemisphere was less significant compared to that in the right side in the 3VO rats. The left and right ratio was 0.67 +/- 0.15 (P < 0.05) in the parietal cortex and 0.70 +/- 0.10 (P < 0.01) in the caudate nucleus. This asymmetrical response to acetazolamide administration gradually corrected by 7 days after 3VO. A significant increase of the LCPV in the ischemic side was observed between day 0 and the 5th day. The 3VO rat is a useful model for studies on the pathophysiology of a hemodynamically compromised state.