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Kemmelmeier FS, Bracht A. Effects of the nonsteroidal anti-inflammatory drug mefenamic acid on energy metabolism in the perfused rat liver. Biochem Pharmacol 1989; 38:823-30. [PMID: 2930582 DOI: 10.1016/0006-2952(89)90237-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The action of mefenamic acid, a nonsteroidal anti-inflammatory drug, on energy metabolism in the isolated perfused rat liver was investigated. Mefenamic acid in the range between 0.1 and 1.0 mM was infused to livers from well-fed rats and from 24-hr fasted rats. The former were perfused with substrate-free Krebs/Henseleit-bicarbonate buffer, allowing the measurement of glycogenolysis and glycolysis from endogenous glycogen. The livers from 24-hr fasted rats, on the other hand, were perfused with Krebs/Henseleit-bicarbonate buffer containing fructose, thus allowing the measurement of fructolysis and glucose synthesis. Oxygen consumption was measured in both cases. When present in the range between 0.1 and 0.5 mM, mefenamic acid increased glycolysis, oxygen uptake, glycogenolysis and fructolysis. Higher concentrations, depending on the perfusion conditions, were inhibitory. Glucose production from exogenous fructose, on the other hand, was inhibited at low mefenamic acid concentrations. In general terms, the effects of mefenamic acid on energy metabolism seemed to be the primary consequence of its uncoupling action on the respiratory chain. This conclusion is supported mainly by the opposite effects on glucose synthesis (inhibition) and oxygen consumption (activation). The intracellular concentration of mefenamic acid is much higher than the extracellular one, a phenomenon which may represent binding to intracellular membrane or proteins.
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Affiliation(s)
- F S Kemmelmeier
- Laboratory of Liver Metabolism, University of Maringa, Brazil
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Affiliation(s)
- G D Sweeney
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
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Bornheim LM, Kotake AN, Correia MA. Differential haemin-mediated restoration of cytochrome P-450 N-demethylases after inactivation by allylisopropylacetamide. Biochem J 1985; 227:277-86. [PMID: 3994685 PMCID: PMC1144837 DOI: 10.1042/bj2270277] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Administration of allylisopropylacetamide (AIA) to phenobarbital-pretreated rats results in the destruction of several phenobarbital-inducible cytochrome P-450 isoenzymes and a correspondingly marked loss of benzphetamine N-demethylase and ethylmorphine N-demethylase activities. Accordingly, the ion-exchange h.p.l.c. or DEAE-cellulose-chromatographic profile of solubilized microsomal preparations from such rats revealed a marked decrease in the cytochrome P-450 content of several eluted fractions compared with that of microsomes from corresponding non-AIA-treated controls. Incubation of liver homogenates from such rats with haemin restores not only cytochrome P-450 content from 35 to 62% of original values, but also benzphetamine N-demethylase and ethylmorphine N-demethylase activities, from 23 to 67%, and from 12 to 36% of original values respectively. Moreover, the chromatographic profiles of microsomes prepared from such homogenates indicated increases of cytochrome P-450 content only in some fractions. Reconstitution of mixed-function oxidase activity of cytochrome P-450 by addition of NADPH: cytochrome P-450 reductase to these fractions indicated that incubation with haemin restored benzphetamine N-demethylase activity predominantly, but ethylmorphine N-demethylase activity only minimally. After injection of [14C]AIA, a significant amount of radiolabel was found covalently bound to protein in chromatographic fraction III, and this binding was unaffected by incubation with haemin. Furthermore, the extent of this binding is apparently equimolar to the amount of cytochrome P-450 refractory to haemin reconstitution in that particular fraction. Whether such refractoriness reflects structural inactivation of the apo-cytochrome remains to be determined. Nevertheless, the evidence presented very strongly argues for AIA-mediated inactivation of multiple phenobarbital-induced isoenzymes, only a few of which are structurally and functionally reparable by haemin.
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Prickett KS, Baillie TA. Evidence for the in vitro metabolism of allylisopropylacetamide to reactive intermediates. Mechanistic studies with oxygen-18. BIOMEDICAL MASS SPECTROMETRY 1984; 11:320-31. [PMID: 6478043 DOI: 10.1002/bms.1200110703] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Metabolism of allylisopropylacetamide (AIA) (1) in microsomal preparations from phenobarbital-pretreated rats is shown to proceed by way of three cytochrome P-450-dependent pathways: (i) aliphatic (C-3') hydroxylation, (ii) allylic (C-3) hydroxylation and (iii) olefin oxidation. The latter represents the major route of biotransformation and leads ultimately to the formation of the gamma-butyrolactone 2. In order to elucidate the mechanism by which AIA is converted to this gamma-lactone, and to gain information on the nature of chemically reactive intermediates in the process, the metabolism of AIA to 2 was investigated in 18O2 or H218O and the pattern of label incorporated into the product was determined by gas chromatography/mass spectrometry (GC/MS). The results support the formation of AIA epoxide as an initial product of olefin oxidation and indicate that this species undergoes rapid intramolecular rearrangement to a protonated iminolactone which, in turn, is hydrolysed to the stable gamma-lactone. On the other hand, the 'dihydrodiol' metabolite of AIA, which would be expected to result from direct hydrolysis of AIA epoxide, was not detected in incubation products and, furthermore, the 18O labeling data specifically exclude the possibility that it served as a precursor of 2. It may be concluded, therefore, that AIA epoxide and the protonated iminolactone to which it gives rise represent reactive intermediates in the oxidation of AIA which may play a key role in the alkylation of certain cellular constituents which accompanies metabolism of AIA by liver enzymes.
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Chapter 20. The Inactivation of Cytochrome P-450. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 1984. [DOI: 10.1016/s0065-7743(08)60696-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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Liem HH, Johnson EF, Muller-Eberhard U. The effect in vivo and in vitro of allylisopropylacetamide on the content of hepatic microsomal cytochrome P-450 2 of phenobarbital treated rabbits. Biochem Biophys Res Commun 1983; 111:926-32. [PMID: 6838593 DOI: 10.1016/0006-291x(83)91388-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Rabbits treated with phenobarbital were given a single injection of allylisopropylacetamide (AIA) s.c. and/or heme i.v. Hepatic microsomes were isolated 1, 5 and 24 hours post injection and the microsomal contents of both total cytochrome P-450 chromophore, and the protein moiety of P-450 2 were determined by spectrophotometric and immunochemical methods respectively. AIA caused the levels of total P-450 chromophore and of P-450 2 protein to decline to 30% of the control values at 5 hours post-injection. Concurrent administration of heme with AIA diminished the decrease in the total microsomal content of P-450 chromophore but not in that of P-450 2 protein. These findings suggest that the destruction of the heme prosthetic group of P-450 by suicide substrates such as AIA may lead to an enhanced degradation of the apo-P-450.
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Ortiz de Montellano PR, Mico BA, Mathews JM, Kunze KL, Miwa GT, Lu AY. Selective inactivation of cytochrome P-450 isozymes by suicide substrates. Arch Biochem Biophys 1981; 210:717-28. [PMID: 7305355 DOI: 10.1016/0003-9861(81)90239-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Loosemore M, Wogan G, Walsh C. Determination of partition ratios for allylisopropylacetamide during suicidal processing by a phenobarbital-induced cytochrome P-450 isozyme from rat liver. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)68901-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Klinger W. Liver damage in rats by allylisopropylacetamide (AIA), an inducer of delta-aminolevulinic acid synthetase (ALAS). ACTA PHARMACOLOGICA ET TOXICOLOGICA 1981; 48:404-8. [PMID: 7336955 DOI: 10.1111/j.1600-0773.1981.tb01639.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Twentyfour hours after the intraperitoneal injection of a single dose of allylisopropylacetamide (AIA) in amounts of 100 mg/kg or more to 30-day old male Wistar rats, the livers of most of the animals showed an irregular yellow coloration and a fragile consistency. No macroscopic changes were detected following AIA doses of 25 or 50 mg/kg. Bromsulphthalein retention was not significantly increased after the administration of 25 mg/kg AIA, but distinctly enhanced after 400 mg/kg. Succinate-dehydrogenase-activity in liver homogenate was not altered after 25 mg/kg, but significantly decreased after 400 mg/kg. Ethylmorphine-N-demethylation activity was enhanced after small doses without increase of cytochrome P-450 (cyt. P-450) concentration and decreased after higher doses, accompanied by a remarkable cyt. P-450 loss. GPT activity in serum and liver was not altered after both 25 and 400 mg/kg AIA. GOT activity was slightly but significantly enhanced both in serum and liver after the high dose of 400 mg/kg. Thus in addition to the well-known cyt. P-450 destruction other signs of hepatotoxicity could be demonstrated.
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Maines MD. Effect of allylisopropylacetamide on glutathione metabolism in the rat liver. The possible role of glutathione in the induction of 5-aminolaevulinate synthase. Biochem J 1981; 196:285-92. [PMID: 6118139 PMCID: PMC1162992 DOI: 10.1042/bj1960285] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Administration of allylisopropylacetamide to rats caused a marked decline in the concentrations of reduced and oxidized glutathione in the liver. However, this decrease occurred in the presence of uninhibited activities of gamma-glutamylcysteine synthase and glutathione reductase, and unaltered activities of glutathione transferases A, B and C. The administration of cysteine, the rate-limiting precursor of glutathione formation, to rats treated with allylisopropylacetamide potentiated the inductive effects of the agent on 5-aminolaevulinate synthase, and markedly decreased the extent of decrease in glutathione concentrations by the agent. Conversely, the administration of diethyl maleate, which depletes the hepatic glutathione concentrations, to allylisopropylacetamide-pretreated rats (1h) diminished the extent of 5-aminolaevulinate synthase induction and the production of porphyrins by nearly 50%, when measured at 16h. This treatment did not alter the extent of non-enzymic degradation of liver haem by allylisopropylacetamide. When diethyl maleate was administered to the animals possessing high 5-aminolaevulinate synthase activity (at 3, 7 and 15h after allylisopropylacetamide), in 1h the enzyme activity was markedly decreased. Diethyl maleate had no effect on induction of 5-aminolaevulinate synthase by 3,5-diethoxycarbonyl-1,4-dihydrocollidine, also a potent porphyrinogenic agent. Diethyl maleate alone neither inhibited 5-aminolaevulinate synthase activity nor decreased the cellular content of porphyrins and haem. The data suggest that the decreases observed in the glutathione concentrations after allylisopropylacetamide administration are not the result of decreased production of the tripeptide. Rather, they most likely reflect the increased utilization of glutathione. The findings further suggest that the inhibition by diethyl maleate of allylisopropylacetamide-stimulated 5-aminolaevulinate synthase involves the inhibition of induction processes.
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Ortiz de Montellano PR, Mico BA. Destruction of cytochrome P-450 by allylisopropylacetamide is a suicidal process. Arch Biochem Biophys 1981; 206:43-50. [PMID: 7212720 DOI: 10.1016/0003-9861(81)90063-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Glöckner R, Klinger W. Influence of puromycin and chloramphenicol on aminoketone synthesis ( delta-aminolevulinic acid synthesis) induction by allylisopropylacetamide in rat liver. EXPERIMENTAL PATHOLOGY 1981; 20:215-20. [PMID: 7333365 DOI: 10.1016/s0232-1513(81)80025-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In vitro induction of aminoketone synthesis (AKS) by allylisopropylacetamide (AIA) in liver slices from 30 day-old male rats was reversibly inhibited by puromycin (50 micrograms/ml incubation mixture). Normal AKS was initially stimulated and thereafter blocked. Chloramphenicol (350 micrograms/ml) inhibited AIA mediated induction of AKS only partially and only when added 1 h before AIA to the incubation mixture. In vivo puromycin (3 i.p. injections of 15 mg/kg in 1 h intervals) did not influence AKS or AIA mediated AKS induction in newborn rats, whereas chloramphenicol (500 mg/kg s.c. 30 min prior to AIA) inhibited AIA mediated AKS induction in newborn rats. In 40 day-old rats pretreatment with chloramphenicol completely inhibited AKS induction by 200 mg/kg AIA.
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Farrell G, Correia M. Structural and functional reconstitution of hepatic cytochrome P-450 in vivo. Reversal of allylisopropylacetamide-mediated destruction of the hemoprotein by exogenous heme. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(19)70437-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Maines MD. Evidence for the catalytic activity of endogenous iron in the lipid peroxidative destruction of heme by allylisopropylacetamide in the rat liver. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1980; 12:781-5. [PMID: 7450133 DOI: 10.1016/0020-711x(80)90162-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Ortiz de Montellano PR, Yost GS, Mico BA, Dinizo SE, Correia MA, Kumbara H. Destruction of cytochrome P-450 by 2-isopropyl-4-pentenamide and methyl 2-isopropyl-4-pentenoate: mass spectrometric characterization of prosthetic heme adducts and nonparticipation of epoxide metabolites. Arch Biochem Biophys 1979; 197:524-33. [PMID: 41487 DOI: 10.1016/0003-9861(79)90276-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Farrell GC, Schmid R, Kunze KL, Ortiz de Montellano PR. Exogenous heme restores in vivo functional capacity of hepatic cytochrome P-450 destroyed by allylisopropylacetamide. Biochem Biophys Res Commun 1979; 89:456-63. [PMID: 486175 DOI: 10.1016/0006-291x(79)90651-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Brinkschulte-Freitas M, Uehleke H. The effects of 2,2-diethylallylacetamide on hepatic cytochromes in rats and in vitro. Arch Toxicol 1979; 42:137-46. [PMID: 485854 DOI: 10.1007/bf00316493] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The application of 0.15 and 0.3% of diethylallylacetamide (DA) in the drinking water to rats during 10 days increased the relative liver weight, the yield of hepatic microsomes, and cytochromes P-450 and b5. Single s.c. doses of 400 mg DA per kg reduced cytochrome P-450 concentrations in the hepatic endoplasmic reticulum of rats. This effect was considerably more pronounced in rats pretreated with phenobarbital. The activity of 5-aminolaevulinic acid synthesis in liver mitochondria, and total liver porphyrins increased. In incubations of metabolizing hepatic microsomes from rabbits pretreated with phenobarbital 75% of 0.1 mM DA was degraded after 1 h. The aerobic incubation of 0.1 mM DA with rabbit hepatic microsomes in the presence of NADPH produced 50% destruction of cytochrome P-450 within 1 h. Addition of EDTA revealed that a part of this destruction cannot be explained by accelerated lipid peroxidation.
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Liem H, Smith A, Muller-Eberhard U. Effect of desferrioxamine and chronic iron deficiency of heme metabolism--comparison with the porphyrogens 2-allyl-2-isopropylacetamide and 3,5-diethoxycarbonyl-1,4-dihydrocollidine. Biochem Pharmacol 1979; 28:1753-8. [PMID: 475836 DOI: 10.1016/0006-2952(79)90536-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Edwards PM, Francis JE, De Matteis F. The glutathione-linked metabolism of 2-allyl-2-isopropy-lacetamide in rats. Further evidence for the formation of a reactive metabolite. Chem Biol Interact 1978; 23:233-41. [PMID: 709688 DOI: 10.1016/0009-2797(78)90009-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
2-Allyl-2-isopropylacetamide (AIA) causes a depletion of liver glutathione in rats only if the animals have been pretreated with phenobarbitone. Phenobarbitone stimulates the excretion in bile of a component derived from AIA and glutathione which is apparently not the same as the conjugate formed by reaction of the two components in simple solutions. The significance of these findings are considered in relation to the suggestion that AIA is metabolised to an epoxide by the microsomal enzyme system; in addition several differences between AIA and the non-porphyrogenic compound, acrylamide, are discussed.
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Ortiz de Montellano PR, Mico BA, Yost GS. Suicidal inactivation of cytochrome P-450. Formation of a heme-substrate covalent adduct. Biochem Biophys Res Commun 1978; 83:132-7. [PMID: 697804 DOI: 10.1016/0006-291x(78)90407-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Uehleke H, Brinkschulte-Freitas M. Kinetics and metabolism of 2,2-diethylallylacetamide in dog and man. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1978; 302:11-8. [PMID: 652047 DOI: 10.1007/bf00586590] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Unseld A, de Matteis F. Destruction of endogenous and exogenous haem by 2-allyl-2-isopropylacetamide: role of the liver cytochrome P-450 which is inducible by phenobarbitone. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1978; 9:865-9. [PMID: 744288 DOI: 10.1016/0020-711x(78)90061-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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