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PubMed1977

Adriamycin stimulated superoxide formation in submitochondrial particles.

Adriamycin (doxorubicin), an anticancer agent, stimulated the formation of superoxide in submitochondrial particles isolated from bovine heart. Superoxide formation was detected by oxygen uptake, by the cooxidation of epinephrine to adrenochrome and by the reduction of acetylated cytochrome c. These processes were sensitive to superoxide dismutase (SOD). Rotenone-insensitive oxidation of NADH by the mitochondrial respiratory chain in the presence of oxygen caused the formation of approx 4 nmol of superoxide per min/mg of protein. Adriamycin at a concentration of 400 micron stimulated the rate of superoxide formation 6-fold to 25 nmol.min-1.mg-1, but this was not a maximum rate. Approximately 50 micron adriamycin was estimated to be sufficient for obtaining one-half maximal stimulation. Hydrogen peroxide accumulated as a final reaction product. Measurements of the relative catalase activity of blood-free tissues of rabbits and rats indicated that heart contained 2 to 4% of the catalase activity of liver or kidney. An enhanced production of superoxide and hydrogen peroxide and the relatively low catalase content of heart tissue may be factors in the cardiotoxicity induced by adriamycin chemotherapy if a similar reaction occurs in vivo.

Adrenochrome↗
PubMed1989

Toxicity of aminochromes.

The first part of the present review deals with the chemical and enzymatic synthesis of adrenochrome and other aminochromes from the corresponding catecholamines. A description of the most significant pathways of formation and the reactivity of the aminochromes is presented. In the second part of the toxicity of aminochromes, mainly at the cardiac and CNS level, is described and some of the molecular mechanisms of the toxic action are outlined. The toxicity of the aminochromes appears to depend mainly on the production of reduced oxygen species through redox cycling. The interaction of aminochromes with sulfhydryl groups and the induced depletion of oxygen, ascorbate and glutathione are additional mechanisms resulting in noxious effects at a cellular level.

Adrenochrome↗
PubMed2002

Flow injection spectrophotometric determination of adrenaline in pharmaceutical formulations using a solid-phase reactor containing lead(IV) dioxide immobilized in a polyester resin.

A flow injection spectrophotometric procedure is proposed for determining adrenaline in pharmaceutical formulations. In this work, the adrenaline in acetate buffer reacts with a solid-phase reactor containing lead(IV) dioxide immobilized in a polyester resin and the adrenochrome yielded was continuously monitored at 486 nm. The analytical curve was linear in the adrenaline concentration range from 0.1 to 0.8 mmol l(-1) with a detection limit of 8 x 10(-3) mmol l(-1). Recoveries of 96.5-105% and relative standard deviation of 0.2% for a solution containing 0.4 mmol l(-1) adrenaline (n = 10) were obtained. The analytical frequency was 130 determinations per hour and the results obtained for adrenaline in pharmaceutical formulations using this procedure and those obtained using a pharmacopoeia procedure are in agreement at the 95% confidence level.

Adrenochrome↗
PubMed2000

Spectroscopic detection of adrenaline-quinone formation in micelles.

Spectral changes, from 200 nm to 600 nm, of the oxidation of adrenaline to adrenochrome induced by periodate in electrically charged and neutral micelles at pH 3.77 were studied. The observed variations of the peak position, intensity and shape of the fluorescence spectra indicated that depending on the charge of the micelle adrenaline ion is partially embedded into the micellar core. Fluorescence lifetime measurements using Omnilyzer allowed to calculate partition coefficients of 0.36, 0.05 and 0.01 in sodium dodecyl sulphate, tetradodecyltrimethylammonium bromide and Triton X-100, respectively. Kinetics of adrenaline decay during oxidation were followed by its fluorescence what overcame spectral interference in the absorption spectra of adrenaline from the formed intermediates. Scanning absorption spectroscopy, with 100 ms resolution, allowed the recording of spectral changes during the transformation. With this method, the formation of adrenaline-quinone with absorption maxima at 388 nm and 274 nm was detected. The calculated rate constants of the observed kinetics during oxidation were significantly lowered in both charged micelles compared to buffer solution and in Triton X-100 neutral micelles. The observed phenomena are discussed in terms of the electrostatic forces mechanism and in the frame of the Raper-Mason scheme of adrenaline transformation.

Adrenochrome↗
PubMed1997

Involvement of the reductase domain of neuronal nitric oxide synthase in superoxide anion production.

Neuronal nitric oxide synthase (nNOS) is a modular enzyme which consists of a flavin-containing reductase domain and a heme-containing oxygenase domain, linked by a stretch of amino acids which contains a calmodulin (CaM) binding site. CaM binding to nNOS facilitates the transfer of NADPH-derived electrons from the reductase domain to the oxygenase domain, resulting in the conversion of L-arginine to L-citrulline with the concomitant formation of a guanylate cyclase activating factor, putatively nitric oxide. Numerous studies have established that peroxynitrite-derived nitrogen oxides are present following nNOS turnover. Since peroxynitrite is formed by the diffusion-limited reaction between the two radical species, nitric oxide and O2.-, we employed the adrenochrome assay to examine whether nNOS was capable of producing O2.- during catalytic turnover in the presence of L-arginine. To differentiate between the role played by the reductase domain and that of the oxygenase domain in O2.- production, we compared its production by nNOS against that of a nNOS mutant (CYS-331), which was unable to transfer NADPH-derived electrons efficiently to the heme iron under special conditions, and against that of a flavoprotein module construct of nNOS. We report that O2.- production by nNOS and the CYS-331 mutant is CaM-dependent and that O2.- production can be modulated by substrates and inhibitors of nNOS. O2.- was also produced by the reductase domain of nNOS; however, it did not display the same CaM dependency. We conclude that both the reductase and oxygenase domains of nNOS produce O2.-, but that the reductase domain is both necessary and sufficient for O2.- production.

Adrenochrome↗
PubMed1975

Properties of catechol O-methyltransferases from brain and liver of rat and human.

Kinetic and electrophoretic properties of catechol O-methyltransferases (EC 2.1.1.6) from brain and liver were studied. The enzyme of either rat or human tissues exhibited a single molecular form when subjected to electrophoresis at pH7.9. At pH9 a second, apparently oxidized, form was detected. Isoelectric-focusing experiments also indicated only one enzyme form, which was identical from extracts of brain and liver of each species (pI = 5.2 for rat, 5.5 for human). Similarities between brain and liver catechol O-methyltransferase of a given species were also demonstrated by kinetic parameters, meta/para ratios of products, and inhibitor potencies. Human catechol O-methyltransferase exhibited lower Km values than did the rat enzyme for S-adenosyl-L-methionine, dopamine and dihydroxybenzoic acid. Adrenochrome inhibited both rat and human enzyme. It was concluded (1) that only a single enzyme form could be demonstrated in the physiological pH region; (2) that catechol O-methyltransferase of brain could not be distinguished from the liver enzyme of the same species; and (3) that species differences exist between the enzymes of rat and human tissues.

Adrenochrome↗
PubMed1983

Prooxidant properties of vanadate in vitro on catecholamines and on lipid peroxidation by mouse and rat tissues.

Vanadate (Na3VO4) in micromolar concentrations enhanced the in vitro formation of adrenochrome from epinephrine, and of aminochrome from dopamine. Lipid peroxides in various tissues of the mouse and rat, particularly brain, were increased. Products of both catecholamine oxidation and lipid peroxidation may be the basis of the cardiotoxic and neurotoxic effects of vanadium.

Adrenochrome↗
PubMed1997

Substrate specificity for isomerase activity of macrophage migration inhibitory factor and its inhibition by indole derivatives.

Macrophage migration inhibitory factor (MIF) was discovered as a cytokine that inhibits random migration of macrophages and concentrates them at inflammatory loci. We recently reported the tertiary structure of MIF, and revealed its similarity to that of 5-carboxymethyl-2-hydroxymuconate isomerase. Moreover, MIF was found to have isomerase activity converting D-dopachrome, a stereoisomer of naturally-occurring L-dopachrome, to 5,6-dihydroxyindole-2-carboxylic acid. In this study, we examined the effects of a series of compounds analogous to D-dopachrome on the enzyme activity to obtain vital information for identification of a natural substrate of MIF. Adrenochrome, lacking a carboxyl group at position 2 of the indolinequinone ring, could not be a substrate. Several indole-ring-containing compounds with a carboxyl group were inhibitory to D-dopachrome isomerase activity, of which indole-3-acrylic acid was the most potent inhibitor, with an inhibitor constant (Ki) of 2.8 mM. 2,3-Indolinedione, which lacks a complete indole ring or a carboxyl group but has carbonyl groups at positions 2 and 3, apparently inhibited the enzyme activity in a competitive or mixed manner with a Ki of 0.9 mM. Taken together, these facts suggest that the 2-carboxyl group of the substrate is essential for interaction with the active site of MIF.

Adrenochrome↗
PubMed1976

Generation of the superoxide radical during autoxidation of oxymyoglobin.

Autoxidation of bovine oxymyoglobin to metmyoglobin induces co-oxidation of epinephrine to adrenochrome. This co-oxidation is markedly inhibited by superoxide dismutase [EC 1.15.1.1]. Electron transfer from oxymyoglobin to ferricytochrome c is partially inhibited by superoxide dismutase. These results indicate that autoxidation of oxymyoglobin results in generation of superoxide radicals. Autoxidation of oxymyoglobin is accelerated by superoxide dismutase and partially inhibited by catalase [EC 1.11.1.6].

Adrenochrome↗
PubMed1994

Plasma oxidase assay for screening of myocardial infarction.

The availability of techniques such as surgical reperfusion, angioplasty, and thrombolysis for the treatment of acute myocardial infarction (AMI) has revived interest in seeking an early detectable biochemical marker diagnostic for AMI. Therefore, we investigated whether an unidentified oxidase that is released by activated neutrophils at the onset of AMI could be used as an early diagnostic assay. The conversion by plasma oxidase of 1 microM of adrenaline to 1 microM of adrenochrome represents the plasma oxidase activity (POA) of 1 U/L. Fifty patients suspected of having AMI, 40% of whose electrocardiograms were nondiagnostic for AMI, were admitted to the coronary care unit, and venous blood samples were obtained for determination of the POA and creatine phosphokinase-MB levels. Healthy volunteers (n = 12) served as control subjects, and 8 patients with pneumonia whose leukocyte counts were greater than 15,000 microL were included in the study. In those with AMI (n = 22), as determined by serial creatine phosphokinase-MB, the mean POA (+/- standard error of the mean) was 233 +/- 13 U/L, and in those with angina and no AMI (n = 28) was 127 +/- 5 U/L (P < 0.0001). In the control group, mean POA (+/- standard error of the mean) was 84 +/- 5 U/L (control versus angina; P < 0.01) and for those with infection was 214 +/- 10 U/L. At admission, the creatine phosphokinase-MB was diagnostic for only 12 of the 22 patients with AMI (sensitivity rate of 54%), whereas in 21 of those patients, the POA values were diagnostic for AMI (sensitivity rate of 95%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenochrome↗
PubMed1992

Oxidation of 1,1-diphenylhydrazine to N-nitrosodiphenylamine by superoxide radical in the eye.

By microsomes obtained from bovine ciliary body, 1,1-diphenylhydrazine was oxidized to N-nitrosodiphenylamine in the presence of NADPH. This reaction was stimulated by riboflavin which was recognized to be an electron carrier. The oxidizing activity by microsomes was markedly inhibited by superoxide dismutase, but not by SKF 525-A or carbon monoxide. Similarly, the oxidation of 1,1-diphenylhydrazine to its corresponding nitrosamine occurred in varying degrees when the hydrazine derivative was exposed to visible light in the presence of photosensitizers such as riboflavin, flavin adenine dinucleotide, flavin mononucleotide, lumiflavin, lumichrome, NAD+, NADH, NADP+, or NADPH. The photochemical oxidation was inhibited by active oxygen-scavengers such as superoxide dismutase, L-ascorbic acid or alpha-tocopherol. The superoxide radical involved in the photochemical reaction was determined by measuring the oxidation of epinephrine to adrenochrome. The oxidation of epinephrine was well correlated to that of 1,1-diphenylhydrazine. Thus, the present study provided evidence that the superoxide radical is responsible for the oxidation of a hydrazine derivative to a corresponding nitrosamine by ocular tissue microsomes and by photosensitizers.

Adrenochrome↗
PubMed1963

BLOOD LOSS DURING PEDIATRIC OPERATIONS.

The gravimetric method of measuring blood loss was used during all types of pediatric operations at The Montreal Children's Hospital. Results of 1787 such measurements indicated that the method is of value in the management of transfusion. Grading blood loss as minor, moderate or severe, in terms of its relation to total blood volume or body weight is a procedure of practical value. Operations were grouped into those that usually led to a loss of less than 10% of the blood volume (7.5 ml./kg.), those with a loss usually between 10% and 14% and those with blood loss usually over 14% (10.5 ml./kg.), in order that appropriate plans for transfusion could be made to reduce the incidence of serious hypovolemia without fear of cardiovascular overloading. Blood loss at operation (adenotonsillectomy) was noted to vary considerably among surgeons but was fairly constant for each surgeon and seemed to be independent of the surgeon's experience. Two alleged hemostatic agents, adrenochrome carbazone (Statimo) and estrogenic substances (Premarin), were not effective in reducing the amount of blood lost during adenotonsillectomy. The importance of calculation of approximate equivalent amounts of blood at various ages of childhood is emphasized.

Adenoidectomy↗
PubMed1991

The role of aminochromes in ultraweak luminescence accompanying oxidative metabolism of catecholamines in model systems in vitro.

Ultraweak luminescence (UWL) accompanying oxidative transformations of catecholamines (CA) into melanins, particularly adrenaline and noradrenaline in the model system CA + Fe(CN)6(3-) + OH(-) + H2O2 in vitro was investigated by spectroscopic methods. Separate steps of the oxidative transformations from CA to melanins were analyzed with respect to their energetic/spectroscopic properties in order to evaluate the possibility of chemiexcitation and light emission. Results of experiments with pure adrenochrome + H2O2 + OH- provided evidence pointing to the key role of the interaction between aminochromes and active oxygen species.

Adrenochrome↗
PubMed1990

[Effect of cepharanthin on radiotherapy induced leukopenia].

Cepharanthin, a kind of alkaloid, has been reported to show a protective effect for leukopenia induced by radiation therapy. In this study, one of three kinds of drugs, Cepharanthin, S-Adchnon (adrenochrome derivative) and Hythiol (L-cysteine), was randomly administered to 94 patients with cancer of the head and neck, the uterine cervix and the lung, during the course of radiotherapy. When Cepharanthin was given, 81.3% of the patients were protected from leukopenia, compared with 51.6% in S-Adchnon and 32.3% in Hythiol. It is suggested that prophylactic use of Cepharanthin may be useful for cancer radiotherapy.

Adrenochrome↗
PubMed1990

Semiconductor properties of melanins prepared from catecholamines.

D. C. dark - and photoconductivity measurements were performed with synthetic melanins prepared by oxidative polymerization of dopamine, adrenaline, adrenochrome and adrenolutin. The melanins examined show significant differences in conductivity, thermal activation energy and photocurrent intensity values. The differences in semiconductor properties observed between the melanins reflect the structure differences of catecholamine-melanin polymers.

Adrenochrome↗
PubMed1988

Does captopril attenuate reperfusion-induced myocardial dysfunction by scavenging free radicals?

The abilities of angiotensin converting-enzyme (ACE) inhibitors to suppress superoxide anion formation in vitro and to improve postischemic cardiac function in vivo were examined. Three sulfhydryl-containing ACE inhibitors, captopril, its stereoisomer SQ 14,534, and an analog, zofenopril (SQ 26,703) were compared with enalaprilat and teprotide, which lack the sulfhydryl group but inhibit ACE, and two compounds, N-2-mercaptopropionylglycine (MPG) and N-acetylcysteine (NAC), which contain a thiol moiety but are not ACE inhibitors, for suppression of free radical formation in vitro. The autooxidation of epinephrine to adrenochrome is mediated by superoxide anions and inhibited by captopril, SQ 14,534, and zofenopril, with similar IC50 values of 8 to 10 microM, but not by enalaprilat or teprotide (IC50 greater than 1000 microM). This reaction is also inhibited by MPG and NAC with IC50 values of 19 and 17 microM, respectively. In addition, captopril, MPG, or NAC, but not teprotide or enalaprilat, scavenge superoxide anion production by the purine-xanthine oxidase reaction and by canine neutrophils activated with phorbol myristate acetate. These results indicate that captopril scavenges superoxide anions in vitro independent of an action on ACE, which is probably related to the presence of a sulfhydryl moiety. Myocardial segmental function in the anesthetized, open-chest dog is altered during ischemia from active shortening to passive lengthening. Reperfusion after 15 min of ischemia does not restore active shortening within a 3 hr experimental period. Pretreatment of dogs with captopril intravenously (5 mg/kg) results in a 40% to 60% return to active shortening within 60 min of reperfusion. In contrast, equihypotensive doses of enalaprilat do not improve segmental function during reperfusion. Dogs given captopril immediately before restoring coronary blood flow show a similar return of function as that observed in animals treated with the drug before occlusion. SQ 14,534, the isomer of captopril, which is 100-fold less potent as an ACE inhibitor but equipotent in scavenging superoxide anions, also improves reperfusion-induced cardiac dysfunction when administered at reperfusion (5 mg/kg). Thus captopril improves postischemic contractile derangements by a mechanism independent of ACE inhibition. Restoration of blood supply to the ischemic myocardium provokes ventricular fibrillation in 37.5% of control dogs but in only 9% of those administered enalaprilat and 0% of captopril-treated animals. SQ 14,534 does not reduce the incidence of ventricular fibrillation (40%), indicating that the antifibrillatory actions may be related to ACE inhibition.(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenochrome↗
PubMed1987

Kinetic study of sinephrine oxidation by mushroom tyrosinase.

Mushroom tyrosinase catalyzes the oxidation of sinephrine showing a marked lag period during appearance of adrenochrome and simultaneously adrenaline accumulation in the reaction medium can be detected. The adrenaline accumulation follows a sigmoidal curve until a constant level of adrenaline is reached when the system is in the steady-state. These experimental results agree with a model of enzymatic catalysis that includes the chemical evolution of adrenoquinone and permit us to explain these phenomenon as well as the influence that enzyme and sinephrine concentration present on the lag period and the level of adrenaline accumulated in the steady-state.

Adrenochrome↗
PubMed1984

[Inhibition of superoxide-dependent processes by aminoglycoside antibiotics].

The ability of various antibiotics to inhibit superoxide anion(O-2)-mediated formation of adrenochrome from adrenaline and recovery of cytochrome c by xanthine oxidase was studied. In the adrenaline system (pH 10.2), aminoglycosides might be arranged, according to the inhibitory effect, in the following order: monomycin greater than gentamicin greater than kanamycin greater than lincomycin greater than streptomycin. In the xanthine oxidase system (pH 7.8), that order was the following: monomycin greater than gentamicin greater than lincomycin greater than greater than kanamycin. It was suggested that the antibiotic inhibition of the O-2-dependent processes at the essential sites of metabolism and/or the antibiotic involvement into the process of free radical oxidation initiated by O-2 in the cells might be one of the mechanisms of the drug action and toxicity with respect to the host.

Adrenochrome↗