Recovery of brain microcirculation during ischemia

Blood pressure in the circle of Willis in rats decreased to about 40 mmHg after ligation of both carotid arteries. Developing ischemia was accompanied by massive adhesion of leukocytes to the walls of brain venules and the smallest veins. Blood pressure in the vessels of the circle of Willis decreased to 16-20 mmHg 2 h after ligation. The number of adhesion events increased sharply. Leukocyte aggregates formed in these vessels, resulting in complete occlusion of the vessels and death of the animals. These processes were found to be reversible. Introduction of 4-4.5 ml of the plasma replacement polyglucin directly into the vessels of the circle of Willis "washed away" the leukocyte aggregates and some of the adhered leukocytes, with restoration of circulation in venules and the smallest veins by 10-15 min.