Possible Interaction: Methotrexate and Thiamine Pyrophosphate

“Both the ability of the liposomes to circumvent the transport defect, and the inability of …-glyceroPE to do so, were anticipated on the basis of previous experiments which show that thiamine pyrophosphate could antagonize inhibition of mouse … L1210 cell proliferation by methotrexate and MTX-gamma-glyceroPE, … inhibition by liposomes.”

“The cytotoxicity of MTX-Cys-SS-αMM46 was not affected by thiamine pyrophosphate , an inhibitor of the active transport of MTX across the cell membrane, but was decreased significantly by ammonium chloride, a lysosomotropic amine.”

“ii) Methotrexate inhibits TPP influx. (”

“iii) TPP competitively inhibits methotrexate influx. (”

“ Thiamine pyrophosphate , an inhibitor of MTX transport, can prevent the cytotoxicity of the free MTX but not that of the anti-SSEA-1 conjugate.”

“However, MTX-DMPE I sensitized liposomes apparently enter target cells as a consequence of phagocytosis, and not via the ubiquitous methotrexate … use of thiamine pyrophosphate showed that this compound had no influence on inhibition of cell proliferation due to liposomes, whereas thiamine pyrophosphate … methotrexate and MTX-glyceroPE … these liposomes.”

“ Thiamine pyrophosphate , an inhibitor for MTX-transport, protects cells from the toxicity of MTX , but not of MTX-poly(lys).”

“Guthrie et al. (1956) have shown that another group of compounds, cocarboxylase , thiamine, and thiamine pyrimidine, will, however, prevent the inhibitory effect of amethopterin on B. subtilis.”