Hypolipidaemic drugs induce peroxisomal proliferation in the liver and many induce the formation of the hepatic endoplasmic reticulum in general and the formation of cytochrome P-450 in particular. We have induced the formation of rat liver microsomal cytochrome P-450 by the administration of the hypolipidaemic drug clofibrate, isolated the endoplasmic reticulum, solubilized the cytochrome P-45...

Maximum concentrations of microsomal cytochrome P-450 are present in 3-4 day-old mung beans (Phaseolus aureus). On illumination of dark-grown seedlings, cytochrome P-450 and later cytochrome P-450 undergo a rapid decrease in concentration in vivo, with an apparent half-time of about 6 h. Conversely light-grown seedlings, transferred to darkness, show a slow accumulation of cytochrome P-450, dou...

Treatment of male rats with the anticancer drug cisplatin leads to feminization of the profile of cytochromes P-450 and other microsomal enzymes involved in steroid hormone and drug metabolism (G. A. Le Blanc, and D. J. Waxman, J. Biol. Chem., 263: 15732-15739, 1988). The present study uses the rat model to evaluate the differential effects of cisplatin treatment on liver microsomal enzymes bet...

The loss of cytochrome P-450 in cultured rat hepatocytes can be prevented by substituted pyridines, especially isonicotinamide, 3-hydroxypyridine and metyrapone. The effect of these compounds is independent of protein synthesis, suggesting that they maintain pre-existing cytochrome P-450. The efficiency of pyridines at maintaining cytochrome P-450 in hepatocyte culture is highly correlated with...

We have investigated the response of rat liver nuclear, nuclear envelope, and microsomal cytochrome P-450 (or P-448) to various treatments. Responses of these subcellular fractions to 3-methylcholanthrene pretreatment were generally similar. In endoplasmic reticulum preparations, we observed an increase in cytochrome P-450 content following phenobarbital pretreatment, which was reduced by subse...

Using a spectrophotometer connected to a microcomputer, the carbon monoxide difference spectrum of renal microsomal dithionite-reduced cytochrome P-450 was measured avoiding the effects of the contaminating mitochondrial cytochromes and hemoglobin by subtracting the CO difference spectrum of a succinate-treated microsomal suspension from that of a dithionite-treated one. By this method, we quan...

The administration of 3-methylcholanthrene to rats leads to changes in the enzyme systems of the liver which oxidize drugs. These changes have been related to changes in some of the spectral properties of microsomal cytochrome P-450. The altered cytochrome appearing after 3-methylcholanthrene treatment has been called P,-450,’ P-448, P-446, Pa450, and high-spin P-450 by different investigators....

Purified adrenocortical microsomal P-450~21 was incorporated into vesicle membranes composed of phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine a t a molar ratio of 5 3 : 1. Trypsinolysis of the incorporated P 4 5 0 ~ ~ ~ resulted in the formation of 30-, 2 5 , and 20-kDa fragments. Similar fragment formation was observed by trypsinolysis of bovine adrenocortical microsome...

A, androstenedione Arom, aromatase AMH, anti Müllerian hormone cAMP, adenosine 3': 5'cyclic monophosphate DHT, dihydrotestosterone E, estrogen E1, estrone E2, estradiol 17B ER, estrogen receptor FT, female-producing temperature 3B-HSD, 3B-hydroxysteroid dehydrogenase-5-ene-4-ene isomerase 17B-HSD, 17B-hydroxysteroid dehydrogenase hsp, heat-shock protein MT, male-producing temperature P 450 arom...

Inhibitory monoclonal antibodies (MAbs) were used to determine the contribution of epitope-specific cytochrome P-450 isozymes in rat liver microsomes to hydroxylation of the esophageal carcinogen methyl-n-amylnitrosamine. These P-450-catalyzed reactions form 2-, 3-, 4-, and 5-hydroxymethyl-n-amylnitrosamine, formaldehyde (demethylation), and pentaldehyde (depentylation). With uninduced microsom...