To examine the effect of selective microwave hyperthermia on the transport of MTX (methotrexate) across blood-brain barrier. MTX is a prescribed antifolate in cancer chemotherapy for a variety of neoplasms. MTX concentration in brain tissue with or without microwave hyperthermia was compared. Animals received MTX immediatelay, 15, or 45 min following microwave hyperthermia treatment.
Modulation type: CW
Exposure duration: continuous for 20 min
|Exposure duration||continuous for 20 min|
No parameters are specified for this exposure.
The average uptake at the posterior left hemisphere was 2.25 +/- 0.43, 10.40 +/- 2.59, and 17.23 +/- 1.13 µg of MTX per gram of brain tissue for 50, 100, and 200 mg/kg doses, respectively. Brains of rats injected 45 min after exposure were free of MTX. Rats euthanized 15 min post-irradiation had an average midbrain MTX concentration of 2.5 +/- 0.46 µg of tissue. These data indicate that MTX uptake is significantly increased in brains subjected to noninvasive microwave hyperthermia treatment. Furthermore, the increase is reversible within 45 min post-exposure.