Clinical studies on @entity5 and @entity1569 @entity1 have shown that plasma and urinary @entity1255 ( @entity5784 ) responds to @entity1499 ( @entity1500 ) therapy, indicating that Hcy in extracellular fluids may be an indicator of the antifolate effect. However, the clinical data indicate that the burden of proliferating cells, @entity137 and the @entity1501 status are also determinants of extracellular Hcy. To evaluate this further, we investigated the modulation of cellular Hcy egress by @entity1500 , rescue agents, cell proliferation and @entity137 . Nontransformed and chemically transformed fibroblasts and @entity19 @entity706 cells, which are characterized by different growth behavior and @entity1500 response, were used. The Hcy export rate was correlated positively with the proliferation rate in all cell types. @entity4181 or @entity7615 added to fibroblasts not exposed to @entity1500 reduced the Hcy export rate, whereas the export from the @entity706 cells was not affected. All cells types exposed to @entity1500 were rescued by @entity1014 + @entity3625 , and this allowed the assessment of Hcy export during @entity1500 exposure without interference from @entity137 . In the fibroblasts, @entity1500 with @entity1014 + @entity3625 rescue induced a marked increase in Hcy export, and the dose-response paralleled the @entity137 curves obtained for @entity1500 without rescue. Nontoxic concentrations of @entity1500 without rescue enhanced the Hcy export. When @entity1500 concentration was increased further, Hcy export was stimulated initially, and then declined rapidly as cell death ensued. @entity1500 did not enhance the Hcy export from the @entity706 cells and, in the absence of rescue, the Hcy export from these cells declined in proportion to inhibition of cell growth.(ABSTRACT TRUNCATED AT 250 WORDS)

Interaction between XXXX , "rescue" agents and cell proliferation as modulators of @entity1255 export from cells in culture.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity1501 :: ('MESH:D005492', 'Chemical') :: ['folate'] @entity4181 :: ('MESH:D002955', 'Chemical') :: ['5-Formyltetrahydrofolate'] @entity137 :: ('MESH:D064420', 'Disease') :: ['cytotoxicity'] @entity1569 :: ('MESH:D011565', 'Disease') :: ['psoriasis'] @entity706 :: ('MESH:D008223', 'Disease') :: ['lymphoma'] @entity1255 :: ('MESH:D006710', 'Chemical') :: ['homocysteine'] @entity5 :: ('MESH:D009369', 'Disease') :: ['cancer'] @entity19 :: ('10090', 'Species') :: ['murine'] @entity3625 :: ('MESH:D019271', 'Chemical') :: ['hypoxanthine'] @entity7615 :: ('MESH:C005984', 'Chemical') :: ['5-methyltetrahydrofolate'] @entity5784 :: ('CHEBI:17588', 'Chemical') :: ['Hcy'] @entity1500 :: ('CHEBI:44185', 'Chemical') :: ['MTX'] @entity1014 :: ('MESH:D013936', 'Chemical') :: ['thymidine'] @entity1499 :: ('MESH:D008727', 'Chemical') :: ['methotrexate']
@entity1499 :: (MESH:D008727,Chemical) :: ['methotrexate']
