Pial arterial pressure in cats following middle cerebral artery occlusion. II. Relationship to regional disturbance of energy metabolism.

Abstract

SUMMARY Focal cerebral ischemia was produced in 16 cats by occluding the left middle cerebral artery (MCA) for 120 min. Cortical blood flow and pial artery pressure were determined prior to vascular occlusion and after 15, 60 and 120 min. At the end of the experiments (after 120 min MCA occlusion) heads were frozen in situ with liquid nitrogen. Cooled brains were cut into 0.5 cm thick slices. From these slices twenty-micron sections passing through the territory of the MCA were prepared in a cryostat and used in the pictorial presentation of glucose and ATP. NADH-fluorescence was recorded from the tissue slice, immersed in liquid nitrogen. In addition, tissue samples were taken from regions of interest and used for quantitative determination of biochemical substrates.In all but two animals permanent MCA occlusion led to disturbances in the energy-producing metabolism, as indicated by reduction in glucose and ATP, and increase in lactate. The regions exhibiting bright NADH-fluorescence were much smaller than those in which ATP was absent. In 6 animals NADH-fluorescence was not increased but even decreased in areas with disturbed energy-producing metabolism. A close correlation was obtained after comparing cortical blood flow measured 15 min after MCA occlusion with the area of ATP-depletion at the end of the experiments. However, the size of ATP-depletion did not correlate with flow measured 60 or 120 min after MCA occlusion. It is concluded that in focal ischemia the size of an infarct depends on the reduction in flow occurring immediately after vascular occlusion and that reduction in the NAD/NADH pool may account for the disturbances of the energy-producing metabolism observed following temporary focal ischemia. Stroke Vol 15. No 4. 1984EXPERIMENTAL OCCLUSION of a major supply artery of the brain results in regional cerebral ischemia should blood flow be reduced below the threshold necessary for covering the nutritional demand of brain tissue. 1 " 7 The consequence is the breakdown of the energy-producing metabolism and the well-known concomitant changes in biochemical substrates: a drop in glucose and high-energy phosphates and an increase in lactate and NADH. It has been shown that following 30 min middle cerebral artery (MCA) occlusion in cats the tissue within the ischemic territory is depleted of glucose and ATP and exhibits bright NADH-fluorescence. 8 In the present study the MCA in cats was occluded for 120 min to study whether prolonged vascular occlusion influences the pattern of biochemical substrates. In addition, cortical blood flow and pial artery pressure were evaluated at different times. We found that the size of the ATP-depleted area, evaluated planimetrically on cross-sections of the brain, correlated closely with cortical blood flow following shortterm but not following prolonged occlusion. Furthermore, in several animals there was no increase whatsoever in NADH-fluorescence but rather a decrease within the ischemic territory. The general pathophysiological and hemodynamic findings have alre...

Hemodynamic and Metabolic Disturbances in Acute Cerebral Infarction

“…Since intracranial pressure is $10 mmHg and venous blood pressure is negligibly small, CPP at the capillary level is 10-20 mmHg (Date, Hossmann, & Shima, 1984;Paschen, Shima, & Hossmann, 1984;Shima, Hossmann, & Date, 1983). Mean arterial blood pressure (MABP) is 100 mmHg in the ascending aorta, 70 mmHg in the carotid arteries, 50 mmHg in the middle cerebral arteries, and 20-30 mmHg in the cerebral capillaries.…”

The pathophysiology of experimental brain edema

“…Rev. 12 (1989) Histology ATP Glucose L a c t a t e In stroke edema, in contrast to peritumorous edema, the primary reason for water uptake is the severe metabolic disorder [18,41]. In the center of the MCA territory, ATP and glucose decline, N A D H increases due to the disturbed brain tissue redox state, and pH becomes acid ( Figure 10).…”