Open AccessEFFECT OF AN INHIBITING FACTOR ISOLATED FROM RAT LIVER ON DNA POLYMERASES IN REGENERATING RAT LIVER
Author(s) -
Pietu G.,
Munsch N.,
Mousset S.,
Frayssinet C.
Publication year - 1979
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.1365-2184.1979.tb00122.x
Subject(s) - dna polymerase , dna synthesis , in vivo , polymerase , dna , thymidine , microbiology and biotechnology , biology , enzyme , in vitro , hepatectomy , biochemistry , chemistry , medicine , genetics , surgery , resection
We partially purified an inhibitory factor (LIF), isolated from 105,000 g supernatant of a saline adult rat liver homogenate. LIF stopped in vitro cell multiplication by blocking the G 1 —S transition, and reduced in vivo [ 3 H]thymidine incorporation into liver DNA in two‐thirds hepatectomized rats. This reduction in DNA synthesis was observed at 24 hr after hepatectomy, even when the LIF was injected before the beginning of the S phase, 10 hr after hepatectomy, i.e. when DNA polymerase activity had not yet increased. Under these experimental conditions, LIF in vivo treatment prevented α DNA polymerase activity from increasing after partial hepatectomy, so that enzyme activity at 24 hr in LIF‐treated rats decreased compared to the controls. No direct inhibitory effect of LIF on α DNA polymerase was detected. LIF did not affect β DNA polymerase. These results suggest that LIF plays a part in controlling liver growth.