Comparison of acute hepatocellular proliferating cell nuclear antigen labeling indices and growth fractions, p34cdc2 kinases, and serum enzymes in carbon tetrachloride-treated rats.
We evaluated various biomarkers associated with cell proliferation immediately following insult with the classic hepatotoxicant carbon tetrachloride (CCl4). Rats were administered a single necrogenic dose of CCl4 and euthanized at either t = 4, 8, 12, 16, or 24 hr postdose. Parameters evaluated included the following: immunohistochemical detection of hepatocellular proliferating cell nuclear antigen labeling indices (PCNA-LIs; percentage of cells in S phase) and growth fractions (PCNA-GFs; percentage of cells in the cell cycle); PCNA and the cyclin-dependent kinase p34cdc2 (CDK) protein in S-9 fractions by Western blot and enzyme-linked immunosorbent assay (ELISA); and liver-related serum enzymes. An increase in PCNA-GF was observed at t = 4 hr, concomitant with elevations in CDK and PCNA protein (Western blot). PCNA-LIs were increased by t = 24 hr, as were CDK and PCNA by ELISA. Sorbitol dehydrogenase was the most sensitive enzyme, with increases observed at t = 4 hr. Our results indicate that PCNA-GF, CDK, and PCNA levels reflect hepatocellular regeneration as early as 4 hr following CCl4 insult. We conclude that these assays are early and sensitive indicators of acute hepatotoxicity that may be advantageous to evaluate in the early stages of exploratory studies.
Monticello
T M
TM
Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, New Jersey 08543, USA.
Barton
D
D
Ma
X
X
Babish
J G
JG
Durham
S K
SK
D000410:Alanine Transaminase / Q000097:blood*; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood*; D016203:CDC2 Protein Kinase / Q000187:drug effects*; D002251:Carbon Tetrachloride; D018844:Cyclin-Dependent Kinases / Q000187:drug effects; D007150:Immunohistochemistry; D008099:Liver / Q000737:chemistry* / Q000201:enzymology / Q000276:immunology; D008297:Male; D008940:Mitotic Index / Q000187:drug effects*; D018809:Proliferating Cell Nuclear Antigen / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016196:S Phase / Q000187:drug effects*
D018809:Proliferating Cell Nuclear Antigen; D002251:Carbon Tetrachloride; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D016203:CDC2 Protein Kinase; D018844:Cyclin-Dependent Kinases