Newly developed drug delivery system in cancer chemotherapy using direct electric current

To improve the antitumor effect of chemotherapy on a target organ, we exper imentally investigated pharmacokinetic alteration of methotrexate (MTX) ind uced by an electric current in rats to ascertain whether the local concentr ation of MTX could be enhanced while reducing the concentration in blood. S ix male Wistar rats had platinum electrodes introduced into both kidneys. T hree rats were subjected to direct current (3.5 V, 50 muA) for 3 hours, whi le another three control rats received no current. While providing the curr ent to the treated group, all of the rats were intravenously injected with MTX at a dose of 1 mg/kg. The MTX concentration in urine (excreted from eac h ureter) and serum was measured by fluorescence polarization immunoassay. Cumulative MIX renal excretion rate was significantly higher in the cathode than anode side in the treated group (p < 0.01). Serum MTX concentration a t 0 to 5 min was significantly reduced in the treated group (p < 0.03). The first part of the area under the curve (i.e., alpha curve) was markedly in creased in the treated group versus controls (p = 0.05). Electric therapy u sing a slight direct current could gather anionized MTX to the cathode, whi le reducing MTX concentration in the serum of experimental rats.