IN-VIVO P-31 MAGNETIC-RESONANCE SPECTROSCOPY AND MORPHOMETRIC ANALYSIS OF THE PERFUSED VASCULAR ARCHITECTURE OF HUMAN GLIOMA XENOGRAFTS IN NUDE-MICE

The relationship between the bioenergetic status of human glioma xenog rafts in nude mice and morphometric parameters of the perfused vascula r architecture was studied using P-31 magnetic resonance spectroscopy (MRS), fluorescence microscopy and two-dimensional digital image analy sis. Two tumour lines with a different vascular architecture were used for this study. Intervascular distances and non-perfused area fractio ns varied greatly between tumours of the same line and tumours of diff erent lines. The inorganic phosphate-nucleoside triphosphate (P-i/NTP) ratio increased rapidly as mean intervascular distances increased fro m 100 mu m to 300 mu m. Two morphometric parameters - the percentage o f intervascular distances larger than 200 mu m (ivd(200)) and the non- perfused area fraction at a distance larger than 100 mu m from a neare st perfused vessel (area(100)), - were deduced from these experiments and related to the P-i/NTP ratio of the whole tumour. It is assumed th at an aerobic to anaerobic transition influences the bioenergetic stat us, i.e. the P-i/NTP ratio increased linearly with the percentage of i vd(200) and the area(100).