Purification of a liver DNA-synthesis promoter from plasma of partially hepatectomized rats.
A protein was isolated from plasma of partially (70%) hepatectomized rats that, injected in mice, increases the uptake of [3H]thymidine by liver DNA by 200-300% over that by injected control saline. The purification procedure consists essentially of three chromatography steps, employing Sephadex G-75, DEAE-cellulose and hydroxyapatite. The hepatic promoter (HP) preparation shows a single band in SDS/polyacrylamide (15%)-gel electrophoresis (silver stained), with an Mr of 64 000; its activity is suppressed by trypsin or pepsin and is unaffected by deoxyribonuclease or ribonuclease. On injection into mice (150 ng/mouse), it increases the mitotic index of the liver. It shows organ-specificity, acting on liver but not on spleen, kidney, lung or brain. In primary liver cultures, it produces an increase in uptake of [3H]thymidine into DNA in the range 1-10 ng/ml. In this system in vitro, it increases the uptake of 22Na+ immediately after addition.
D000818:Animals; D001798:Blood Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D002469:Cell Separation; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004247:DNA / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D006498:Hepatectomy; D066298:In Vitro Techniques; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D051381:Rats; D011919:Rats, Inbred Strains
D001798:Blood Proteins; D004247:DNA