Right brain regions of anesthetized rats were loaded with [3,5,7-3H]methotrexate (3H]MTX) or with [14C]sucrose by infusing the tracers into the right carotid artery, after the blood-brain barrier had been opened by right carotid infusion of a hypertonic arabinose solution. During the 6 hr following the procedure, the [3H]MTX concentration in 7 right-sided brain regions, when normalized to the plasma concentration integral during tracer infusion, fell, with an average half-time of 4.8 hr as compared to less than 20 min for the initial rate of toss of [14C]sucrose. Right-left brain concentration differences 3 hr after treatment were statistically significant (p < 0.05) for [3H]MTX but not for [14C]sucrose. The results indicate that intracerebral [3H]MTX is lost more slowly than is intracerebral [14C]sucrose, possibly because [3H]MTX enters brain cells, whereas [14C]sucrose remains largely extracellular.
|Original language||English (US)|
|Number of pages||5|
|State||Published - Mar 1 1985|
ASJC Scopus subject areas
- Cancer Research