Polyol content of cerebrospinal fluid in brain-tumor patients

In order to investigate whether cerebrospinal fluid (CSF) polyols are consumed by brain tissue, the concentration of seven polyols in the CSF and the serum of 30 patients with intracranial tumor and 17 control individuals was measured by gas chromatography. The mean polyol content in the control samples showed that the fructose, inositol, and glucitol levels were significantly greater in CSF than in serum. A comparison of the lumbar CSF from control subjects and 11 patients with malignant tumors exposed to the CSF showed the fructose and inositol levels to be significantly lower (54% and 45%, respectively) and the glucose content to be slightly higher (110%) in the tumor cases. These differences were markedly greater in the ventricular than in the lumbar CSF and greater in patients with tumors exposed to the CSF space than in those with tumors buried in the brain tissue. In ventricular CSF obtained from seven patients with malignant brain tumors before and after radio- and/or chemotherapy, significant increases in fructose (34%) and glucitol (48%) levels were found, but the other polyols did not change significantly. In culture, the human glioblastoma cell growth rate was higher in the medium containing fructose and glucose than in that containing glucose alone. A notable amount of fructose and glucose was consumed by cultured glioblastoma cells. The roles of polyols contained in CSF and the effects of fructose on the growth of cultured glioblastoma cells are discussed in light of these findings and of previous reports.