Rapid metabolic failure in spontaneously hypertensive rats after middle cerebral artery ligation.

The metabolic characteristics of the penumbral region were examined in spontaneously hypertensive rats one hour after permanent middle cerebral artery occlusion. The effect of hyperglycemia on this region was examined by providing a glucose load prior to occlusion. The depressed concentrations of adenosine triphosphate and elevated levels of lactate in the penumbral region were similar to those found in the ischemic focus. The purported neuroprotective effect of hyperglycemia in the penumbral region was not reflected in an increased high-energy phosphate level in the penumbral region. The rapid deterioration of the metabolic status of this region in this strain of rat suggests that the increased consistency of infarction may come at the expense of the penumbral region, and thus this model may not be well suited for the study of metabolic changes and perhaps even therapeutic intervention.