TY - JOUR T1 - Studies Relating to the Mode of Action of Methotrexate JF - Molecular Pharmacology JO - Mol Pharmacol SP - 303 LP - 317 VL - 5 IS - 4 AU - J. BORSA AU - G. F. WHITMORE Y1 - 1969/07/01 UR - http://molpharm.aspetjournals.org/content/5/4/303.abstract N2 - The methotrexate-induced inhibition of thymidylate and of purine synthesis has been studied in L-cells in tissue culture under conditions which permitted the separation of the two types of inhibition. Data are presented which suggest that under the conditions employed methotrexate may have sites of action in addition to its inhibition of folate and dihydrofolate reductase. These findings are discussed in relation to the strengths and weaknesses of the noe-site-of-action hypothesis. ACKNOWLEDGMENTS We thank Drs. W. R. Bruce and J. E. Till for helpful discussions. ER -