[The effect of etoposide on influx and efflux of cytosine arabinoside in P388 murine leukemic cells].
We studied the effects of etoposide on the influx, intracellular accumulation and efflux of ara-C in P388 leukemic cells. Etoposide inhibited the active influx of ara-C in a dose dependent manner, and the inhibition was reversible. Etoposide also affected the intracellular accumulation of ara-C, though its inhibitory effect for the intracellular accumulation was weaker than that for the influx of ara-C. It was also shown that etoposide inhibited the active efflux of ara-C. Furthermore, etoposide inhibited the active transport of ara-C bidirectionally but the insensitive route of etoposide existed especially at high concentration of ara-C. The effect of inhibition of the transport of ara-C on the accumulation of ara-C was more significant at lower concentration of ara-C. Judging from the drug concentrations used in this study, an interaction between etoposide and ara-C could occur in the clinical treatment.
Ooi
K
K
Department of Pharmacy, Social Insurance Hazu Hospital, Yokkaichi, Japan.
Ohkubo
T
T
Kuwabara
H
H
Higashigawa
M
M
Sakurai
M
M
D000818:Animals; D003561:Cytarabine / Q000378:metabolism*; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D005047:Etoposide / Q000494:pharmacology*; D007941:Leukemia P388 / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D014407:Tumor Cells, Cultured
D003561:Cytarabine; D005047:Etoposide