Translocation of epidermal growth factor to the hepatocyte nucleus during rat liver regeneration
To determine the fate of exogenous epidermal growth factor (EGF) in regenerating liver, /sup 125/I-labeled EGF was injected into rat portal veins at various times after 70% hepatectomy. Epidermal growth factor was taken up by the liver remnant at all time points studied (0, 4, 8, 16, and 36 h), but at 8 h after hepatectomy a large quantity was retained by the liver and EGF degradation products appearing in the bile decreased markedly. Electron microscopic autoradiography of the regenerating livers 1 h after injection of /sup 125/I-EGF demonstrated that 27% of the grains were associated with hepatocyte nuclei compared to 0.5% in sham-operated controls. There was also a concomitant decrease in grains associated with the lysosomal compartment. Nuclei isolated from regenerating livers exposed to /sup 125/I-EGF also demonstrated a three-fold increase in radioactivity compared to nuclei from control livers. Nearly 70% of nuclear radioactivity was precipitable with a specific antibody to EGF, and a small fraction appeared to be part of a high molecular weight complex. These data support the hypothesis that during the pre-S phase of liver regeneration, EGF is translocated to the nucleus rather than to lysosomes, and may participate in the initiation of deoxyribonucleic acid synthesis or alteration of gene expression.
- Research Organization:
- Veterans Administration Medical Center, San Francisco, CA
- OSTI ID:
- 6618852
- Journal Information:
- Gastroenterology; (United States), Journal Name: Gastroenterology; (United States)
- Country of Publication:
- United States
- Language:
- English
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LIVER
BIOLOGICAL REGENERATION
PEPTIDE HORMONES
BIOCHEMICAL REACTION KINETICS
AUTORADIOGRAPHY
BILE
BIOLOGICAL PATHWAYS
CELL NUCLEI
DNA REPLICATION
GENETICS
HEPATECTOMY
IODINE 125
RATS
ANIMALS
BETA DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BIOLOGICAL RECOVERY
BIOLOGY
BODY
BODY FLUIDS
CELL CONSTITUENTS
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
ELECTRON CAPTURE RADIOISOTOPES
GLANDS
HORMONES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
KINETICS
MAMMALS
MATERIALS
MEDICINE
NUCLEI
NUCLEIC ACID REPLICATION
ODD-EVEN NUCLEI
ORGANS
RADIOISOTOPES
REACTION KINETICS
RECOVERY
RODENTS
SURGERY
VERTEBRATES
550301* - Cytology- Tracer Techniques