Enzymatic Conversion of [1-13C]pyruvate to [1-13C]lactate in Glioma Rat Model Evaluated by 11.7T NMR Correlated with DCE-MRI at 3T.

Jin Seo¹, Hyun Jin Park¹, Youn-Ki Nam², Young Han Lee¹, Ho-Taek Song¹, Jin-Suck Suh¹

Among the various metabolites involved in the glucose metabolism of the tumor, pyruvate and lactate are the highlighted metabolites in the up-regulated glucose metabolism of malignant neoplasm. The purpose of this study is to determine the enzymatic conversion of [1-13C]pyruvate to [1-13C]lactate with exclusion of magnetization transfer effect from the hyperpolarized ¹³C. Enzymatic conversion ratio of [1-13C]lactate/pyruvate in glioma and normal brain were evaluated ex-vivo by using 11.7T NMR. DCE-MRI elucidated the vascular permeability characteristics of highly metabolic glioma. In-vitro cellular LDH assay of C6 glioma cells proved enzyme activity. The conversion ratio and quantitative DEC-MRI parameter K_ep were correlated.