title: Phenobarbital stimulation of cytochrome P-450 and aminopyrine N-demethylase in hyperplastic liver nodules during LD-ethionine carcinogenesis.
abstract: Microsomes isolated from hyperplastic liver nodules and hepatomas, induced by DL-ethionine, exhibited a reduced cytochrome P-450 content and aminopyrine N-demethylase activity when compared to the organelles of control and surrounding non-nodular liver. Phenobarbital administration to rats caused an increase of microsomal protein, cytochrome P-450 and aminopyrine N-demethylase in all tissue tested. In the hepatoma the rise of cytochrome P-450 and aminopyrine N-demethylase/g of tissue was very low and it is compensated by a slight increase of microsomal protein. In hyperplastic nodules as well as in control and surrounding livers, cytochrome P-450 and aminopyrine N-demethylase increased more than microsomal protein. However, the phenobarbital-induced stimulation was significantly lower in hyperplastic nodules than in control and surrounding livers.
mesh_terms: D000633:Aminopyrine N-Demethylase / Q000378:metabolism*; D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D005001:Ethionine; D006965:Hyperplasia / Q000378:metabolism; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000378:metabolism*; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D009363:Neoplasm Proteins / Q000378:metabolism; D010634:Phenobarbital / Q000494:pharmacology*; D011230:Precancerous Conditions / Q000139:chemically induced / Q000378:metabolism*; D051381:Rats
chemical_list: D009363:Neoplasm Proteins; D003577:Cytochrome P-450 Enzyme System; D000633:Aminopyrine N-Demethylase; D005001:Ethionine; D010634:Phenobarbital