Glucuronidation and sulfation of p-nitrophenol in isolated rat hepatocyte subpopulations. Effects of phenobarbital and 3-methylcholanthrene pretreatment.
Parenchymal cells, isolated from untreated (control), phenobarbital(PB)-or 3-methylcholanthrene(3-MC)-treated rats, were separated into four subpopulations according to cell density, and glucuronidation and sulfation of p-nitrophenol (PNP) in the hepatocyte subpopulations were investigated. PB enhanced the glucuronidation almost 2-fold but not the sulfation, while 3-MC enhanced both glucuronidation (3-fold) and sulfation (2-fold) in the original cell suspensions. Some gradation trends were found in the conjugation activities among the hepatocyte subpopulations: In the control experiment, the extent of glucuronidation in four subpopulations was virtually the same but sulfation in high-density hepatocytes was slightly higher than in low-density ones. Both glucuronidation and sulfation were higher in low-density hepatocytes from PB-treated rats, though the gradation was very modest. Glucuronidation and sulfation tended to be slightly higher in middle-density hepatocytes in the 3-MC experiment. However, no definite correlation in conjugation activities vs. cell density, like those seen in cytochrome P-450s vs. cell density in the hepatocytes isolated from PB-treated rats, were found in the subpopulations from control or inducer-treated rats. Simultaneous studies on acetylation of p-aminobenzoic acid (PABA) revealed that the activities in the subpopulations were virtually the same and the inducers had little influence on the activity.
D010129:4-Aminobenzoic Acid / Q000378:metabolism; D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis; D005965:Glucuronates / Q000378:metabolism*; D066298:In Vitro Techniques; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D008748:Methylcholanthrene / Q000494:pharmacology*; D009578:Nitrobenzenes / Q000378:metabolism; D009596:Nitrophenols / Q000378:metabolism*; D010634:Phenobarbital / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013431:Sulfates / Q000378:metabolism*
D005965:Glucuronates; D009578:Nitrobenzenes; D009596:Nitrophenols; D013431:Sulfates; C023379:4-nitrophenyl sulfate; D008748:Methylcholanthrene; D003577:Cytochrome P-450 Enzyme System; D010129:4-Aminobenzoic Acid; C024836:4-nitrophenol; D010634:Phenobarbital