Related Experiment Video
Updated: Aug 12, 2026

Partial Lobular Hepatectomy: A Surgical Model for Morphologic Liver Regeneration
Published on: May 31, 2018
The repression and derepression of hepatic tyrosine aminotransferase by carcinogens
Abstract:
Like hydrocortisone, a single carcinogenic dose of dimethylnitrosamine (50 mg/kg) initiates the induction cycle for hepatic tyrosine aminotransferase in adrenalectomized rats. However, following this initial induction in the presence of dimethylnitrosamine, the enzyme becomes refractory to reinduction by known inducers. The administration of thioacetamide to either adrenalectomized or intact rats leads to an immediate and progressive loss of inducibility by hydrocortisone, dibutyrylcyclic AMP or dimethylnitrosamine. Although the thioacetamide-induced repression was not reversed even up to 10 weekds after the cessation of treatment, it was reversed after the induction of liver regeneration. Both the carcinogen-mediated induction and repression of tyrosine aminotransferase appears to occur by mechanisms which do not involve the corticosteroid-binding proteins which normally mediate the induction by glucocorticoids.
More Related Videos
11:36Induction of Drug-Induced, Autoimmune Hepatitis in BALB/c Mice for the Study of Its Pathogenic Mechanisms
Published on: May 29, 2020
09:32Drug-Induced Senescence in Liver Cells Promotes M2 Macrophage Polarization: Implications for Tyrosine Kinase Inhibitor-Associated Hepatotoxicity
Published on: October 17, 2025
Related Concept Videos
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Mutagenicity and Carcinogenicity
Phase II Reactions: Acetylation Reactions
The substrates for acetylation are typically drugs or their metabolites with an amino, sulfonamide, or hydrazine functional group. Acetylation can occur at several points in the drug molecule, including primary, secondary, and...
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Bioactivation and Tissue Toxicity