The uptake of tritiated methotrexate by an experimental glioma.

the interstitial space and much less in tumor cells. At 10 min, the high interstitial uptake persisted, but in addition most neoplastic cells had become labeled. The tumor showed very little remaining interstitial radioactivity but very high cellular uptake 60 min after injection. In the brain at all times after injection, there was very little extravascular uptake. These studies show that this glial tumor rapidly accumulated MTX-3H from the bloodstream. Initially,