Induction of cytochrome P450 by phenobarbital in rat liver visualized by monoclonal antibody immunoelectron microscopy in situ.
A panel of murine monoclonal antibodies was produced against phenobarbital-inducible cytochrome P450-PB of rat liver in order to establish specific immunological tools for studying the induction process in situ by immunoelectron microscopy and in vitro by a novel ELISA. Antibody 573/64 was found to be useful for both approaches. The immunolabeling procedure with protein A-colloidal gold applied to Lowicryl K4M-embedded rat liver revealed the rough ER as the primary site of cytochrome P450-PB induction. This organelle showed the highest labeling density 12 h after administration of phenobarbital while after maximal enzyme induction at day 5 the labeling density was highest in the smooth ER. Maximal increase in cytochrome P450-PB was 21-fold by morphometric analysis and 15-fold by ELISA. In addition, the enzyme apparently does neither recycle through the Golgi apparatus nor is it degraded in lysosomes when maximally induced.
Marti
U
U
Department of Pharmacology, University of Basel, Switzerland.
Hauri
H P
HP
Meyer
U A
UA
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis*; D004591:Electrophoresis, Polyacrylamide Gel; D004790:Enzyme Induction / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay; D015151:Immunoblotting; D008099:Liver / Q000201:enzymology* / Q000648:ultrastructure; D008297:Male; D016253:Microscopy, Immunoelectron / Q000379:methods; D010634:Phenobarbital / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D000911:Antibodies, Monoclonal; D003577:Cytochrome P-450 Enzyme System; D010634:Phenobarbital