Abstract

Background: Current glioma grading schemes are limited by subjective histological criteria. Imidazoline I₂ receptors are principally expressed on glial cells.

Objective: To investigate the feasibility of using the measurement of imidazoline I₂ receptor expression to differentiate glial tumours from other types of brain tumours and for grading the different gliomas.

Methods: The specific binding of [³H]idazoxan to imidazoline I₂ receptors was measured in homogenates from human gliomas of different grades.

Results: The density of imidazoline I₂ receptors was significantly greater in the three types of malignant glial tumours than in postmortem control brain or non-glial tumours. The increase in density correlated with the malignancy grade of the gliomas. No significant differences in affinity values were observed.

Conclusion: These results suggest that the density of imidazoline I₂ receptors may be a useful radioligand parameter for the differentiation of glial tumours from other types of brain tumours and for grading the different gliomas.