• 1 January 1982
    • journal article
    • research article
    • Vol. 66  (3) , 499-504
Abstract
The effects of 3 antifolates, methotrexate (MTX), triazinate (TZT), and a trimethoxyquinazoline derivative (TMQ), and of cytarabine (ara-C) on leukocyte-committed colony-forming cells from 3 spp. were compared using an assay allowing in vivo metabolism in an agar diffusion chamber. Dose-survival curves approximated plateaus and the level of the plateau was variable among species. Canine marrow colony-forming cells were less sensitive to MTX (.apprx. 90% survival) than those from mice or man (25-40% survival). Human marrow colony-forming cells were less sensitive (70% survival) to TZT than those from mice or dogs (25% survival). No interspecies differences were found for TMQ or ara-C. Mouse marrow in situ was less sensitive to i.v. MTX than mouse marrow in the chamber. No such difference was found for i.v. TMQ or ara-C. This comparison could not be made for i.p. TZT. [Myelosuppression is one of the major toxic effects of the antifolates.].