The Study Of Time Course Of Brains Metabolites In Hypoxic-ischemic Rats After Sacrifice

Hypoxic-ischemic encephalopathia is the second leading cause of mortality worldwide. It is estimated to be responsible for 9.5% of all deaths and 5.1 million of the 16.7million cardiovascular disease deaths. In China, hypoxic-ischemic encephalopathia is the leading cause of mortality and it is threating life of people worldwide. Hypoxic-ischemic encephalopathia, however, is most complicated process and its procedure occurs in brain will result in multineurodisfunction, including: failure of energy metabolitic produce, changes in multiactive compound in brain and serious sequelae. So it is necessary to reveal the pathological mechanism of hypoxic-ischemic encephalopathia and find effective approach for prevention and treatment.At present study we induced rat model to mimic the procedure of hyperacute hypoxic-ischemi encephalopathia to study the time courses of multimetabolic(Choline, NAA, P-Cr, Lac)dynamic changes in rat brains model of hyperacute global cerebral ischemia within 20 min.A total of 80 rats were randomized into five different groups, the normal (n=5), the hyperacute global cerebral ischemic groups (n=5). A rat model of acute global cerebral ischemia was induced by cutting the rat heads. The lactate concertrations were measured by lactate kit, the four brain metabolitics were measured by HPLC and 9.4T 1HMRS.In the normal group and the ischemic group, the time course of metabolites were revealed, significant differences in Lac, NAA and P-Cr concentration were found between two groups(P<0.05). The marked increase in Lac, and declined in P-Cr and NAA (P<0.05). However, Choline concentration was not significant change in all groups within 20 min after cerebral ischemia period(P>0.05). The earliest detection of lactate was at 20 seconds within the ischemic period, the lactate concentration elevated and peaked at 20s and declined with development of ischemia at 5min reached the ebb, after the ebb lactate began to rise. Methods were compaired between Lac kit and HPLC, the coefficient of correlation is r=0.814; and the methods between HPLC and 1H-MRS, the coefficient of correlation is r=0.900.In conclusion, the time courses of multimetabolites in ischemic rat brains were depict in early stage: abnormalities in acute stage of cerebral ischemia in rats could also be detected by 1H-MRS and another two methods. The study shows that 1H-MRS is a reliable and gave important information for evaluating hypoxic and ischemic pathologic procedure.