Alpha1-acid glycoprotein as a hepatocyte-specific mitosis-inhibiting protein in regenerating rat liver.
The humoral inhibitor, which may play a primary role in the regulatory mechanism of cell division in the regenerating rat liver, was investigated by isolating the active principle from the ethanol-precipitate (P-3 fraction) of normal rat plasma by isoelectric focusing, and determining the exact nature of the active principle by physicochemical analysis, and studying its localization in the liver by immunofluorescence method. The active principle was demonstrated to be alpha 1-acid glycoprotein by physicochemical analysis and by the immunohistological examination to be synthesized in the cytoplasm of the hepatocyte and excreted from it before its mitosis. These results show that the humoral inhibitor or the hepatocyte-specific mitosis-inhibiting protein is alpha 1-acid glycoprotein itself. Based on these findings, a new hypothesis concerning the regulatory mechanism of cell division in general is proposed.
D000818:Animals; D006023:Glycoproteins / Q000502:physiology*; D008099:Liver / Q000166:cytology; D008115:Liver Regeneration; D008297:Male; D008938:Mitosis; D009928:Organ Specificity; D051381:Rats
D006023:Glycoproteins