Wyniki wyszukiwania

1

A wound inducible cytochrome P450 from tomato

100%

Bartoszewski G., Mujer C. V., Smigocki A. C., Niemirowicz-Szczytt K.

Acta Physiologiae Plantarum

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2000

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tom 22

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nr 3

2

Tubular and vascular actions of cytochrome P450-arachidonate metabolites

100%

Carrol M. A., Balazy M., McGiff J. C.

Journal of Physiology and Pharmacology. Supplement

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1993

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tom 44

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nr 2

3

Central serous chorioretinopathy induced by drugs metabolized by cytochrome P450 3A4

88%

Morawski K., Klonowska A., Kubicka-Trzaska A., Woron J., Romanowska-Dixon B.

Journal of Physiology and Pharmacology

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2020

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tom 71

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nr 2

4

Expression of cytochrome CYP2B1-2 in nonpregnant, pregnant and fetal rats exposed to tobacco smoke

88%

Czekaj P., Wiaderkiewicz A., Florek E., Wiaderkiewicz R.

Acta Biochimica Polonica

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2000

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tom 47

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nr 4

Four-month-old female Wistar rats were exposed for 20 days to tobacco smoke obtained from non-filter cigarettes. During the exposure, concentration of tobacco smoke was monitored indirectly by measuring the CO level (1500 mg/m3 air). The efficacy of exposure was assessed by measuring urine nicotine and cotinine levels. Cigarette smoke did not change total cytochrome P450 and b5 protein levels in any of the organs studied, and most of these organs did not show any changes in the activity of reductases associated with these cytochromes. Following exposure to tobacco smoke, fetal rat liver expressed CYP2B1/2 protein; in newborns (day 1) both liver and lung showed CYP2B1/2 protein expression and very low pentoxyresorufin O-dealkylase activity. Western blot analysis of adult liver, lung, heart, but not of brain microsomes, showed that tobacco smoke induced CYP2B1/2 in both nonpregnant and pregnant rats, though its expression was lower in the livers and hearts of pregnant females. In the rat and human placenta, neither rat CYP2B1/2 nor human CYP2B6 showed basal or tobacco smoke-induced expression at the protein level. This study shows clearly that the expression of CYP2B1/2, which metabolizes nicotine and some drugs and activates carcinogens, is controlled in rats by age-, pregnancy-, and tissue-specific regulatory mechanisms.

5

Inhibition of CYP17 expression by adrenal androgenes and transforming growth factor-beta in adrenocortical cells

88%

Biernacka-Lukanty J. M., Lehmann T. P., Trzeciak W. H.

Acta Biochimica Polonica

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2004

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tom 51

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nr 4

Cytochrome P450c17, encoded by the CYP17 gene, is a component of the 17a-hy- droxylase/17,20-lyase enzyme complex essential for production of adrenal glucocorticoids and androgens as well as gonadal androgens. The expression of CYP17 in adrenocortical cells is stimulated by corticotropin (ACTH) via the signal transduction pathway involving cAMP and protein kinase A (PKA). Thus, in addition to glucocorticoids, ACTH stimulates formation of adrenal androgens, which are known to induce transforming growth factor 3 (TGF-3) secretion. TGF-3 in turn inhibits steroid hormone output by attenuating both basal and ACTH-dependent expression of CYP17. The present study revealed that treatment of bovine and human H295R adrenocortical cells with androgens resulted in a decrease in the basal level of CYP17 transcript and cortisol secretion, without affecting forskolin-stimulated levels. We also demonstrated that in H295R cells TGF-3 inhibited both basal and forskolin-stimulated accumulation of CYP17 mRNA. Determination of promoter activity, directing luciferase reporter gene expression in H295R cells transfected with deletion fragments of bovine CYP17 promoter, indicated that the -483 to -433 bp fragment of the promoter was necessary for the inhibitory action of TGF-3 on CYP17 expression. It is concluded that in bovine and human adrenocortical cells, androgens inhibit basal CYP17 expression probably at the transcriptional level and independently of the effect of TGF-3.

6

Effect of piperine, a major component of black pepper, on the pharmacokinetics of domperidone in rats

75%

Alhumayyd M. S., Bukhari I. A., Almotrefi A. A.

Journal of Physiology and Pharmacology

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2014

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tom 65

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nr 6

7

Effect of a monoclonal antibody against cytochrome P-450 on the metabolism of benzo(a)pyrene in C57B1/10 mouse liver microsomes

75%

Brauze D., Mikstacka R.

Bulletin of the Polish Academy of Sciences. Biological Sciences

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1989

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tom 37

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nr 10-12

8

Effects of adenosine receptor agonists and antagonists on cytochrome P450 extinction in the liver of rats in the course of acute pancreatitis

75%

Celinski K., Madro A., Czechowska G., Slomka M., Prozorow-Krol B., Biskup W., Malm A., Juda M., Wielosz M.

Medycyna Weterynaryjna

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2007

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tom 63

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nr 05

528-531

In the course of acute pancreatitis the liver is an organ that is especially exposed to damage. The presence of adenosine receptors was observed in the whole digestive system. The aim of the experiment was to define the correlation between the extinction of cytochrome P450 in the liver of rats and adenosine receptor agonists and antagonists in the course of necrotizing acute pancreatitis. The experiments were carried out on Wistar male rats weighing 250 g. Acute pancreatitis was induced injecting 5% sodium taurocholate to the biliary-pancreatic duct. Prior to the induction of acute pancreatitis the animals were injected intraperitoneally with selective agonists and antagonists: CGS 21680 (selective A2 agonist), 3 mg/kg, ZM 241385 (selective A2a antagonist), 3 mg/kg, DPCPX (A1 antagonist), 1 mg/kg, 1.3-Dipropyl-8-phenylxantine (selective A1 antagonist), 3 mg/kg, IB-MECA (A3 agonist), 0.75 mg/kg. The determinations were performed in hepatic microsomes obtained according to Guegenrichs method Cytochrome P450 extinction was determined by Matsubars technique. The results obtained reveal statistically significantly decreased cytochrome P450 extinction after sodium taurocholate administration. Decreased levels of extinction were also observed after combined administration of sodium taurocholate + Phenylxantine and sodium taurocholate + ZM. The level of IB-MECA remained unchanged in comparison to the controls. However DPCPX and CGS administration increased the extinction of cytochrome P450. The diverse influence of adenosine receptor agonists and antagonists used in the experiment on cytochrom P450 extinction seems to modify the course of the inflammatory process after using 5% sodium taurocholate.

9

Cytochrome P-450 metabolites in renal circulation and excretion - interaction with nitric oxide [NO] system

75%

Kompanowska-Jezierska E., Kuczeriszka M.

Journal of Physiology and Pharmacology. Supplement

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2008

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tom 59

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nr 9

137-149

10

Effects of ethanol and-or ethylene glycol on metabolic enzymes in rats

75%

Olszowy Z., Nowicka J., Plewka A., Plewka D., Nowaczyk G., Kaminski M.

Acta Poloniae Toxicologica

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2001

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tom 09

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nr 1

11

Estradiol and progesterone release from biodegradable copolymer: effect on activity of microsomal mixed function oxidase system in rat liver

75%

Plewka A., Kaminski M., Glogowska-Szelag J., Nowak M., Buntner B., Gorski J., Kajdaniuk D.

Polish Journal of Environmental Studies

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1996

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tom 05

|

nr 4

The cytochrome P-450 dependent monooxygenase system is responsible for metabolism of exo- and endogenous compounds. It is induced or inhibited by many factors, including hormones. The effects of hormones on this system depend on the dose, manner and route of administration. The aim of this study was to test a controlled long-acting system of estradiol-progesterone release from a biodegradable copolymer and to evaluate the influence of the copolymer alone, or the copolymer with estradiol or progesterone on the hepatic enzymatic system responsible for biotransformation of xenobiotics. We have shown that the copolymer slightly affects the activity of the cytrochrome P-450 - dependent mixed oxygenase system (MFO), but not the desaturase system. Estradiol and progesterone modified the MFO activity in a typical manner.

12

In vivo effect of diallyl sulfide and cimetidine on phenacetin metabolism and bioavailability in rat

75%

Szutowski M. M., Zalewska K., Jadczak M., Marek M.

Acta Biochimica Polonica

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2002

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tom 49

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nr 1

Numerous cytochrome P450 inhibitors have been described as effective modulators of cytochrome P450 isoforms activity in vitro. Their inhibitory efficiency may be considerably modified after in vivo application. The aim of this study was to examine the effect of oral administration of diallyl sulfide — a cytochrome P450 2E1 inhibitor and cimetidine — a cytochrome P450 2C6 and 2C11 inhibitor on rat serum concentration of phenacetin and its metabolite acetaminophen. Both inhibitors increased area under the curve (AUC0-4h) for phenacetin by 50%. Only cimetidine reduced AUC0-4 h for acetaminophen indicating inhibition of O-deethylation activity. Quinidine — a cytochrome P450 2D subfamily and P-glycoprotein inhibitor did not change significantly phenacetin bioavailability. These results suggest that diallyl sulfide inhibits the deacetylation pathway catalysed by arylamine N-acetyl transferase. Beside cytochrome P450 1A2 other cytochrome P450 isoforms (2A6 and/or 2C11) are involved in phenacetin O-deethylation in rat.

13

Pharmacokinetic implications of herb-drug interactions

75%

Szalek E., Grzeskowiak E., Kozielczyk J.

Herba Polonica

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2006

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tom 52

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nr 4

Numbers of patients who use easily available herbal medicines are growing rapidly. The drugs are often regarded to be a safe alternative when conventional therapies are not effective. Testing drug pharmacokinetics in vivo is of special importance. It is to be remembered that an interaction predicted theoretically and confirmed in vitro does not have to implicate a clinical importance. In the paper several important herb-drug interactions occurring in the pharmacokinetic phase are reported. Interactions occurring in the biotransformation phase are the most common and of particular importance, especially if cytochrome P450 (CYP) isozymes are involved. Determining changes in pharmacokinetics enables modifying doses of interfering drugs.

14

Effect of coal dusts containing heavy metals on structure, cellular enzymatic markers, and cytochrome P-450-dependent monooxygenase system in rat kidney

75%

Trzeciak H. I., Kaminski M., Plewka A., Malecki A., Pudelko A.

Polish Journal of Environmental Studies

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1996

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tom 05

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nr 2

We evaluated morphological changes, the activities of succinate dehydrogenase, lactate dehydrogenase, glucose-6-phosphatase, Mg2+ -dependent adenosine triphosphatase, and acid phosphatase, and the activity of the cytochrome P-450-dependent monooxygenase system in the kidneys of rats exposed to coal dusts containing either very low or high amounts of heavy metals. We showed that the coal dust with a very low content of heavy metals (VLCHM) did not produce any structural lesions, but increased significantly the activities of the enzymes. These changes probably reflected kidney adaptation to the unfavorable conditions caused by the metals. The interactions among them reduced the eventual nephrotoxic effect of their action. The coal dust with a high content of heavy metals (HCHM) damaged proximal convoluted tubules, straight tubules, and, to a lesser degree, distal convoluted tubules, especially those of long-looped nephrones. The levels and the activities of the assayed cytochromes decreased significantly in the kidneys of rats exposed to HCHM coal dust.

15

Effect of coal dusts containing heavy metals on the structure, cellular enzymatic markers, and cytochrome P-450-dependent monooxygenase system in rat kidneys

75%

Trzeciak H. I., Kaminski M., Plewka A., Malecki A., Pudelko A.

Polish Journal of Environmental Studies

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1995

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tom 04

|

nr 4

We evaluated morphological changes, the activities of succinate dehydrogenase, lactate dehydrogenase, glucoso-6-phosphatase, Mg2+-dependent adenosine triphosphatase, and acid phosphatase, and the activity of the cytochrome P-450-dependent monooxygenase system in rat kidneys exposed to coal dusts containing either low or high amounts of heavy metals. We showed that the coal dust with a very low content of heavy metals (VLCHM) did not produce any structural lesions, but significantly increased the activities of the enzymes. These changes probably reflected kidney adaptation to unfavorable conditions caused by the metals. The interactions among them reduced the eventual nephrotoxic effect of their action. The coal dust with high content of heavy metals (HCHM) damaged proximal convoluted tubules, straight tubules, and, to a lesser degree, distal convoluted tubules, especially those of long-looped nephrones. The levels and the activities of the assayed cytochromes decreased significantly in the kidneys of rats exposed to HCHM coal dust.

16

Toxicological and cytophysiological aspects of lanthanides action

75%

Palasz A., Czekaj P.

Acta Biochimica Polonica

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2000

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tom 47

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nr 4

Lanthanides, also called rare-earth elements, are an interesting group of 15 chemically active, mainly trivalent, f-electronic, silvery-white metals. In fact, lanthanides are not as rare as the name implies, except for promethium, a radioactive artificial element not found in nature. The mean concentrations of lanthanides in the earth's crust are comparable to those of life-important elements like iodine, cobalt and selenium. Many lanthanide compounds show particular magnetic, catalytic and optic properties, and that is why their technical applications are so extensive. Numerous industrial sources enable lanthanides to penetrate into the human body and therefore detailed toxicological studies of these metals are necessary. In the liver, gadolinium selectively inhibits secretion by Kupffer cells and it decreases cytochrome P450 activity in hepatocytes, thereby protecting liver cells against toxic products of xenobiotic biotransformation. Praseodymium ion (Pr3+) produces the same protective effect in liver tissue cultures. Cytophysiological effects of lanthanides appear to result from the similarity of their cationic radii to the size of Ca2+ ions. Trivalent lanthanide ions, especially La3+ and Gd3+, block different calcium channels in human and animal cells. Lanthanides can affect numerous enzymes: Dy3+ and La3+ block Ca2+-ATPase and Mg2+-ATPase, while Eu3+ and Tb3+ inhibit calcineurin. In neurons, lanthanide ions regulate the transport and release of synaptic transmitters and block some membrane receptors, e.g. GABA and glutamate receptors. It is likely that lanthanides significantly and uniquely affect biochemical pathways, thus altering physiological processes in the tissues of humans and animals.

17

Enzymatic redox reactions of the explosive 4,6-dinitrobenzofuroxan [DNBF]: implications for its toxic action

75%

Nemeikaite-Ceniene A., Sarlauskas J., Miseviciene L., Anusevicius Z., Maroziene A., Cenas N.

Acta Biochimica Polonica

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2004

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tom 51

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nr 4

With an aim to understand the toxicity mechanisms of the explosive 4,6-dinitro- benzofuroxan (DNBF), we studied its single-electron reduction by NADPH:cyto- chrome P450 reductase and ferredoxin: NADP reductase, and two- electron reduction by DT-diaphorase and Enterobacter cloacae nitroreductase. The enzymatic reactivities of DNBF and another explosive 2,4,6-trinitrotoluene (TNT) were similar, except for the much lower reactivity of DNBF towards nitroreductase. DNBF was less cytotoxic in FLK cells than TNT. However, their action shared the same mechanisms, oxidative stress and activation by DT-diaphorase. The lower cytotoxicity of DNBF may be explained by the negative electrostatic charge of its adduct with water which may impede cellular membrane penetration, and by the formation of its less reactive adducts with intracellular reduced glutathione.

18

Effect of pyrantel and dimethoate administration on rat liver cytochrome P450 system

75%

Wiaderkiewicz R., Zasadowski A., Czekaj P., Wiaderkiewicz A., Czajkowska B., Barski D., Palasz A.

Bulletin of the Veterinary Institute in Puławy

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2006

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tom 50

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nr 2

19

10-undecynoic acid, an inhibitor of cytochrome P450 4A1, inhibits ethanolamine-specific phospholipid base exchange reaction in rat liver microsomes

75%

Lenart J., Pikula S.

Acta Biochimica Polonica

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1999

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tom 46

|

nr 1

1,12-Dodecanedioic acid, the end-product of w-hydroxylation of lauric acid, stimulates in a concentration dependent manner, phosphatidylethanolamine synthesis via ethanolamine-specific phospholipid base exchange reaction in rat liver endoplasmic reticulum. On the other hand, administration to rats of 10-undecynoic acid, a specific inhibitor of w-hydroxylation reaction catalyzed by cytochrome P450 4A1, inhibits the ethanolamine-specific phospholipid base exchange activity by 30%. This is accompanied by a small but significant decrease in phosphatidylethanolamine content in the endoplasmic reticulum and inhibition of cytochrome P450 4A1. On the basis of these results it can be proposed that a functional relationship between cytochrome P450 4A1 and phosphatidylethanolamine synthesis exists in rat liver. Cytochrome P450 4A1 modulates the cellular level of lauric acid, an inhibitor of phospholipid synthesis. In turn, ethanolamine-specific phospholipid base exchange reaction provides molecular species of phospholipids, containing mainly long-chain polyunsaturated fatty acid moieties, required for the optimal activity of cytochrome P450 4A1.

20

Evidence for aromatase localization in cytoplasmic droplet of human immature ejaculated spermatozoa

75%

Rago V., Bilinska B., Palma A., Ando S., Carpino A.

Folia Histochemica et Cytobiologica

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2003

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tom 41

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nr 1

Ograniczanie wyników

A wound inducible cytochrome P450 from tomato