Effect of hemorrhagic shock duration on the activity of nuclear Ca2+/Mg(2+)-dependent DNA-endonucleases in canine cerebral cortex.

A direct correlation between the duration of arterial hypotension (40 mmHg) and the activity value of nuclear Ca2+/Mg(2+)-dependent DNA-endonucleases was revealed in dogs exposed to hemorrhagic shock. Thus, an increase in the activity of endonucleases was significant after 2 h of arterial hypotension. During that period there activity amounted to 4149 +/- 295 units/mg of protein instead of 2839 +/- 231 units/mg protein in the control (P < 0.

Ischemic brain edema as a complication of decompensated hypovolemic shock.

Four-hour arterial hypotension (decompensated phase) in dogs caused by acute blood loss, when the level of arterial pressure of 40 mmHg was maintained beginning from the 2nd and 3rd h by intra-arterial intermittent blood transfusion is an adequate model for reproducing a moderate ischemic edema of the brain. Pronounced hypoperfusion and considerable disturbances in blood fluidity testified to greater severity of hypoxic and hemorheological disturbances in the microvessles of the brain in decompensated animals than in their compensated counterparts. The formation of a brain edema is based on disturbed fluid circulation closely related to the structural pathology of the organelle membranes of the cells of the nervous and vascular tissues.