Document Detail

Antifolate transport in L1210 leukemia cells. Kinetic evidence for the non-identity of carriers for influx and efflux.
MedLine Citation:
PMID:  974145     Owner:  NLM     Status:  MEDLINE    
The kinetics of methotrexate transport in L1210 cells are described. Data derived from the measurmenets of initial influx, the complete time-course of uptake, intracellular steady-state level and unidirectional efflux were found to be consistent with a simple empirical equation containing three constants. Properties of the system include the following: (1) saturability of initial influx: (2) approach to steady state during uptake is exponential; (3) the half-time for drug uptake is independent of external concentration and equal to half-time for efflux; and (4) transport is concentrative at low external concentrations, whereas the reverse is true at high external concentrations. These observations are incorporated into a kinetic model which quantitatively accounts for the data on the basis of the hypothesis that influx and efflux take place via different carriers.
M Dembo; F M Sirotnak
Related Documents :
1675955 - Influence of external k+ on potassium efflux in isolated chicken enterocytes.
2488755 - Effect of inhibitors of slow calcium current on resting calcium efflux from cat papilla...
874875 - Effects of cardiac aglycones on the sodium efflux in barnacle muscle fibres.
9255405 - Beta-adrenergic-induced calcium efflux in rat parotid gland. is mitochondrial na+/ca2+ ...
1677045 - Beneficial effects of yohimbine on posthypoxic recovery of cardiac function and myocard...
12877905 - Diethylstilbestrol and tetrahydrochrysenes are calcium channel blockers in human platel...
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Biochimica et biophysica acta     Volume:  448     ISSN:  0006-3002     ISO Abbreviation:  Biochim. Biophys. Acta     Publication Date:  1976 Oct 
Date Detail:
Created Date:  1976-12-23     Completed Date:  1976-12-23     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0217513     Medline TA:  Biochim Biophys Acta     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  505-16     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Biological Transport, Active
Leukemia L1210 / metabolism*
Methotrexate / metabolism*
Mice, Inbred Strains
Models, Biological
Reg. No./Substance:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Characteristics of changes in the intracellular potential associated with transport of neutral, diba...
Next Document:  Membrane transport properties of bovine articular cartilage.