Corpus ID: 16151916

On the nature of a transport alteration determining resistance to amethopterin in the L1210 leukemia.

@article{Sirotnak1968OnTN,
  title={On the nature of a transport alteration determining resistance to amethopterin in the L1210 leukemia.},
  author={Francis Michael Sirotnak and Satoshi Kurita and Dorris J. Hutchison},
  journal={Cancer research},
  year={1968},
  volume={28 1},
  pages={
          75-80
        }
}
The uptake of amethopterin-3H by L1210 leukemia cells appears to be mediated, probably, via an active transport mechanism. Uptake occurred against a concentration gradient, was temperature dependent, required a readily available source of energy, exhibited a pH optimum of 7.6 and conformed to Michaelis-Menten kinetics. The maximum intracellular concentration of unbound amethopterin-3H accumulated at equilibrium was 8-fold the external concentration. Both folate and H2-folate compete with… Expand
Comparative studies on the transport of aminopterin, methotrexate, and methasquin by the L1210 leukemia cell.
TLDR
All three drugs appear to be transported by the same mechanism, since competition for the same carrier component among the three drugs, as well as between them and the normal analogs, folate and folinate, was demonstrated with the expected quantitative relationships. Expand
Transport of Melphalan by Sensitive and Resistant Li 2 i 0 Cells 1
The in vitro transport of L-p-(di-2-Chloroethylamino)[14C]phe nylalanine by i.p. grown mouse L1210 leukemias has been studied in melphalan-sensitive and melphalan-resistant cell populations. As hasExpand
Evidence for a transport carrier of nitrogen mustard in nitrogen mustard-sensitive and -resistant L5178Y lymphoblasts.
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Carrier-mediated transport of the folic acid analogue, methotrexate, in the L1210 leukemia cell.
TLDR
It is indicated that methotrexate transport in the L1210 cell is carrier-mediated and uphill, and the implication of these findings with respect to the development of more effective folic acid antagonists is considered. Expand
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TLDR
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SITES OF ACTION OF AMETHOPTERIN: INTRINSIC AND ACQUIRED DRUG RESISTANCE *
TLDR
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The properties of the folate transport system in H35 hepatoma cells have been studied by measuring the transport of (+)-5-methyltetrahydrofolate. Using initial rates of uptake, it has beenExpand
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TLDR
A kinetic model is incorporated into the system which quantitatively accounts for the data on the basis of the hypothesis that influx and efflux take place via different carriers. Expand
Characterization of the methotrexate transport defect in a resistant L 1210 lymphoma cell line.
TLDR
Evidence suggests that the apparent influx in the former cell line may consist of MTX binding to the cell membrane together with a small degree ofMTX influx into the intracellular compartment. Expand
Drug response, dihydrofolate reductase, and cytogenetics of amethopterin-resistant Chinese hamster cells in vitro.
TLDR
The data suggest that increased levels of dihydrofolate reductase may be the primary determinant of response for some sublines whereas for others additional factors such as different enzyme form or altered transport may also influence sensitivity to drug. Expand
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