Open AccessEffect of Methotrexate On Cells In A Keratinized Epithelium With an Active Thymidine Salvage Pathway Assessed By Autoradiography *
Author(s) -
Møller Ulla,
Keiding Niels,
Larsen Jörgen Knud
Publication year - 1984
Publication title -
cell proliferation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.647
H-Index - 74
eISSN - 1365-2184
pISSN - 0960-7722
DOI - 10.1111/j.1365-2184.1984.tb00608.x
Subject(s) - cheek pouch , thymidine , dna synthesis , methotrexate , epithelium , flow cytometry , microbiology and biotechnology , biology , de novo synthesis , chemistry , hamster , biochemistry , dna , immunology , enzyme , genetics
In the partially synchronized cell system of the hamster cheek pouch epithelium, the inhibitory effect of a bolus injection of methotrexate (Mtx) (2 g/m 2 , injected at 1200 hr) was analysed by means of both autoradiography and flow cytometry (FCM) in a 21‐hr experiment. For autoradiography [ 3 H]TdR and [ 3 H]UdR were used as tracers for salvage and de nouo pathways of thymidylate (TMP) synthesis, respectively. For FCM no tracers were injected. the autoradiographic studies demonstrated an active TdR salvage pathway for DNA synthesis, not affected by the impaired de novo TMP synthesis. the blocked de novo TMP synthesis was partially released 7 hr after Mtx injection, but it had not totally recovered at the end of the experiment. the decrease in the fraction of S‐phase cells detected about 10 hr after Mtx injection by autoradiographic labelling with [ 3 H]TdR and by FCM was found to be caused by a decrease in the number of cells entering S phase. However, Mtx did not influence the salvage TMP synthesis rate of cells entering S phase.)