(/sup 3/H)Methotrexate loss from the rat brain following enhanced uptake by osmotic opening of the blood-brain barrier

Journal Article · Fri Mar 01 00:00:00 EST 1985 · Cancer Res.; (United States)

OSTI ID:5612831

Ohata, M; Fredericks, W R; Neuwelt, E A; Sundaram, U; Rapoport, S I

Right brain regions of anesthetized rats were loaded with (3,5,7-/sup 3/H)methotrexate ((/sup 3/H)MTX) or with (/sup 14/C)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 (/sup 3/H)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 loss (/sup 14/C)sucrose. Right-left brain concentration differences 3 hr after treatment were statistically significant (p less than 0.05) for (/sup 3/H)MTX but not for (/sup 14/C)sucrose. The results indicate that intracerebral (/sup 3/H)MTX is lost more slowly than is intracerebral (/sup 14/C)sucrose, possibly because (/sup 3/H)MTX enters brain cells, whereas (/sup 14/C)sucrose remains largely extracellular.

• Research Organization: National Institute on Aging, Bethesda, MD
• OSTI ID: 5612831
• Journal Information: Cancer Res.; (United States), Vol. 45:3
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
METHOTREXATE
METABOLISM
TISSUE DISTRIBUTION
BLOOD-BRAIN BARRIER
BRAIN
CARBON 14 COMPOUNDS
RATS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANIMALS
ANTIMETABOLITES
BODY
CENTRAL NERVOUS SYSTEM
DISTRIBUTION
DRUGS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
NERVOUS SYSTEM
ORGANS
RODENTS
VERTEBRATES
550501* - Metabolism- Tracer Techniques