Abstract: Changes of phosphates related to energetic metabolism such as PCr, Pi, ATP in C57 mouse brain in hypoxia were observed noninvasively by ³¹P in vivo NMR method. When the content of oxygen was reduced to 5%, the concentrations of PCr, ATP decreased while Pi increased, pH of brain cell decreased to 6.83~6.93. Mice were reoxygenated when the ratio of peak heights of Pi to PCr were about 1.Those that the ratio of pi after and before reoxygenation were larger than 1 and pH in reoxygenation increased immediately, could be recovered, otherwise couldn't be recovered. The results showed that Pi and pH reflect the degree of brain damage in hypoxia.

Key words: NMR, ³¹P in vivo NMR, Energetic metabolism, Hypoxia