Changes of Lactate Concentration in Ischemic Rat Brain after Sacrifice

The purpose of this study was to explore the time course of cerebral lactate concentration in ischemic rat brain after sacrifice, in which area the morphology signal was still normal in the early phase. Ischemic rat model was used in this study. Eighty rats were fasted overnight before sacrifice and divided into 16 groups randomly. Lactate concentration was measured by using LD kit. Results showed that lactate reached the highest level rapidly during 20sec to 40 seconds and the mean peak value was 4.06 mmol/100g wet weight at the 20sec point. After 40 seconds, lactate declined gradually and then kept in high level after 3 minutes. The experiment indicated that lactate was observed as the main substrate and indicator of ischemia in early phase of the ischemic rat brain. Twenty-second may be the time threshold of the ischemia neurons to start using lactate as energy resource.