The role of iron chelates on the selectivity of Fenton reagent in hydroxylation, N-demethylation, and sulfoxidation of cimetidine: A novel biomimetic model for the regioselectivity of cytochrome P-450

1988 ◽  
Vol 261 (1) ◽  
pp. 12-15 ◽  
Author(s):  
Shmuel Zbaida ◽  
Rami Kariv ◽  
Paula Fischer
Keyword(s):  
Iron Chelates ◽  
Fenton Reagent ◽  
Cytochrome P 450

scholarly journals Role of Cytochrome b5 in Hydroxylation by a Reconstituted Cytochrome P-450-containing System

1974 ◽  
Vol 249 (21) ◽  
pp. 6701-6709
Author(s):  
Anthony Y.H. Lu ◽  
Susan B. West ◽  
Mary Vore ◽  
Dene Ryan ◽  
Wayne Levin
Keyword(s):  
Cytochrome B5 ◽  
Cytochrome P 450

scholarly journals Decrease in hepatic cytochrome P-450 by cobalt. Evidence for a role of cobalt protoporphyrin

1982 ◽  
Vol 204 (1) ◽  
pp. 103-109 ◽  
Author(s):  
J F Sinclair ◽  
P R Sinclair ◽  
J F Healey ◽  
E L Smith ◽  
H L Bonkowsky
Keyword(s):  
Chick Embryo ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Cobalt Protoporphyrin ◽  
Cytochrome P 450 ◽  
Hepatic Cytochrome

Exposure of cultured chick-embryo hepatocytes to increasing concentrations of CoCl2 in the presence of allylisopropylacetamide results in formation of cobalt protoporphyrin, with a reciprocal decrease in haem and cytochrome P-450. Treatment of rats with CoCl2 (84 mumol/kg) and 5-aminolaevulinate (0.2 mmol/kg) also results in formation of cobalt protoporphyrin and a decrease in cytochrome P-450 in the liver. Hepatic microsomal fractions from rats treated with phenobarbital, CoCl2 and 5-aminolaevulinate were analysed by polyacrylamide gel electrophoresis. Cobalt protoporphyrin was associated mainly with proteins of 50000-53000 mol.wt. The results suggest that the formation of cobalt protoporphyrin occurred at the expense of the synthesis of haem, leading to a decrease in cytochrome P-450. Furthermore, the cobalt protoporphyrin that was formed may itself have been incorporated into apocytochrome P-450.

Role of PGI2 and epoxyeicosatrienoic acids in relaxation of bovine coronary arteries to arachidonic acid

1993 ◽  
Vol 264 (2) ◽  
pp. H327-H335 ◽  
Author(s):  
M. Rosolowsky ◽  
W. B. Campbell
Keyword(s):  
Arachidonic Acid ◽  
Coronary Arteries ◽  
Vascular Tone ◽  
Epoxyeicosatrienoic Acids ◽  
Lipoxygenase Inhibitor ◽  
Physiological Processes ◽  
Coronary Vascular Tone ◽  
Cytochrome P 450 ◽  
Endothelium Dependent Relaxation

Metabolites of arachidonic acid regulate several physiological processes, including vascular tone. The purpose of this study was to determine which metabolites of arachidonic acid are produced by bovine coronary arteries and which may regulate coronary vascular tone. Arachidonic acid induced a concentration-related, endothelium-dependent relaxation [one-half maximum effective concentration (EC50) of 2 x 10(-7) M and a maximal relaxation of 91 +/- 2% at 10(-5) M] of bovine coronary arteries that were contracted with U-46619, a thromboxane mimetic. The concentration of 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha), a metabolite of prostaglandin I2 (PGI2), increased from 82 +/- 6 to 328 +/- 24 pg/ml with arachidonic acid (10(-5) M). Treatment with the cyclooxygenase inhibitor indomethacin attenuated arachidonic acid-induced relaxations by approximately 50% and blocked the synthesis of 6-keto-PGF1 alpha. PGI2 caused a concentration-related relaxation (EC50 of 10(-8) M and a maximal relaxation of 125 +/- 11% at 10(-7) M). BW755C, a cyclooxygenase and lipoxygenase inhibitor, inhibited arachidonic acid-induced relaxation to the same extent as indomethacin. When vessels were treated with both indomethacin and BW755C, the inhibition of relaxation was the same as either inhibitor alone. SKF 525a, a cytochrome P-450 inhibitor, reduced arachidonic acid-induced relaxation by approximately 50%. When SKF 525a was given in combination with indomethacin, the relaxation by arachidonic acid was almost completely inhibited. SKF 525a inhibited the synthesis of epoxyeicosatrienoic acids (EETs).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Mushroom Biomass: Some Clinical Implications of β-Glucans and Enzymes

2016 ◽  
Vol 4 (Special-Issue-October) ◽  
pp. 37-47
Author(s):  
Ana Barros ◽  
Vitoria Bell ◽  
Jorge Ferrão ◽  
Vittorio Calabrese ◽  
Tito Fernandes
Keyword(s):  
Secondary Metabolites ◽  
Dietary Supplement ◽  
Biological Response ◽  
Cellular Growth ◽  
Health Promoting ◽  
The Rich ◽  
The Difference ◽  
Cytochrome P 450

Mushrooms have attracted market attention because they are a potential source of bioactive compounds able to perform several functions in organisms with benefits for the health of the consumer. Cultivation processes vary according a) industrial fermentation - in large vats to produce extracted form of mushrooms or b) closed cultivation system - individually grown in jars on an aseptic “substrate” with controlled lighting and irrigation to produce a biomass form of mushrooms. Biomass is the mycelium with primordia (young fruiting body - before the mushroom blooms) containing all the nutrients and active compounds, including β-glucans, enzymes and secondary metabolites. The classification of mushroom biomass varies according to the presentation; the biomass can be classified as a “food” if in powder form or, classified as a “dietary supplement” in tablet form. While tablet mushroom biomass is considered a dietary supplement, mushroom extracts are designated pharmaceutical compounds, pharmanutrients or nutraceuticals. Here we illustrate the difference between mushrooms in the biomass and extract forms, the similarities and differences on its content on enzymes, secondary metabolites and on β-glucans, as a soluble and fermentable fibre. Of particular note is the rich enzyme activity in the biomass form of mushrooms. Such activity includes enzymes that prevent oxidative stress (superoxide dismutase), enzymes that prevent cellular growth (protease, glucoamylase) and enzymes that promote detoxification (cytochrome P-450, peroxidase, glucose-2-oxidase). β-glucans have been proposed to act as “biological response modifiers” based on their effects on the immune system, and its role in the prevention and treatment of various metabolic syndrome-linked diseases. This review focuses also on some described health-promoting potential of mushroom biomass, all through immunomodulation. The role of intestinal microbiota is enhanced.

Cytochrome P-450 metabolites in endothelin-stimulated cardiac hormone secretion

2004 ◽  
Vol 286 (5) ◽  
pp. R888-R893 ◽  
Author(s):  
Sook Jeong Lee ◽  
Carol S. Landon ◽  
Stanley J. Nazian ◽  
John R. Dietz
Keyword(s):  
Protein Kinase ◽  
Inhibitory Action ◽  
Ventricular Myocytes ◽  
Hormone Secretion ◽  
Neonatal Rat ◽  
Kinase C ◽  
Neonatal Rat Ventricular Myocytes ◽  
Cytochrome P 450 ◽  
Kinase A

We examined the role of cytochrome P-450-arachidonate (CYP450-AA) metabolites in endothelin-1 (ET-1)-stimulated atrial natriuretic peptide (ANP) and pro-ANP-(1-30) secretion from the heart. 17-Octadecynoic acid (17-ODYA, 10-5 M) significantly inhibited ANP secretion stimulated by ET-1 (10-8 M) in the isolated perfused rat atria and inhibited pro-ANP-(1-30) secretion stimulated by ET-1 (10-8 M) or 20-hydroxyeicosatetraenoic acid in cultured neonatal rat ventricular myocytes (NRVM). In NRVM, 17-ODYA significantly ( P < 0.05) increased secretion of cAMP but had no significant effect on the secretion of cGMP from NRVM. Staurosporine, an inhibitor of protein kinase C, completely blocked the inhibitory action of 17-ODYA, whereas a protein kinase A inhibitor, H-89 (5 × 10-5 M), did not significantly attenuate the effects of 17-ODYA. The results show that the inhibitory action of 17-ODYA on ET-1-augmented ANP secretion is mediated through cAMP and suggest that CYP450-AA may play an important role in ET-1-induced cardiac hormone secretion.

The Role of Cytochrome P-450 in Microsomal Mixed Function Oxidation Reactions

1968 ◽  
pp. 142-195 ◽  
Author(s):  
R. W. Estabrook ◽  
A. Hildebrandt ◽  
H. Remmer ◽  
J. B. Schenkman ◽  
O. Rosenthal ◽  
...  
Keyword(s):  
Oxidation Reactions ◽  
Cytochrome P 450
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