PERIPHERAL BENZODIAZEPINE RECEPTORS AND GLUCOSE-METABOLISM IN HUMAN GLIOMAS

Peripheral benzodiazepine receptors (PER) are increased in gliomas and augmented glucose metabolism is seen in malignant brain tumors. We investigated the relationship between PER density (B-max) and glucose utilization rate (GUR) in 17 patients with cerebral gliomas of different grades. PER B-max was assessed by [H-3]PK-11195 in vitro binding in surgical specimens and GUR was measured by Positron Emission Tomography with [F-18]2-Fluorodeoxyglucose before the surgery. In untreated tumors there was a positive correlation between PER B-max and GUR (2(r) = 0.84). This correlation was not observed in patients who had been treated with radiation and/or chemotherapy prior to surgery (r(2) = 0.13). In addition, in untreated patients, the increase in PER density and GUR appeared to be related to the degree of malignancy.