Alterations in malondialdehyde concentration of jugular vein blood following transient brain ischemia. The effect of lactic acidosis.

Ischemia was induced for 10 min with a subsequent 60-min reperfusion and the changes of the malondialdehyde (MDA) concentration in the blood samples from the jugular vein were investigated in normo- and hyperglycemic dogs. Selective brain ischemia was evoked by the increase in cerebrospinal fluid (CSF) pressure. The experiments were carried out in 4 experimental groups. In sham operated animals (Group I) the blood MDA concentration did not change. The venous blood MDA content significantly elevated for 10 min after the start of reperfusion in normoglycemic animals (Group II). To study the effect of acidosis during ischemia and reperfusion on brain lipid peroxidation (LP) processes 1 and 2 g/kg glucose infusion was used in Groups III and IV. As an effect of ischemic lactic acidosis due to hyperglycemia the elevation of MDA concentration in the jugular vein blood was higher and it lasted longer than in the cases of normoglycemia. This finding supports the hypothesis that free radical reactions and LP processes play an important role in the enhanced brain damage caused by tissue acidosis.