Chemiluminescence of <i>Acanthamoeba castellanii</i>

Lloyd, David; Boveris, A; Reiter, Rudolf; Filipkowski, Mark; Chance, Britton

doi:10.1042/bj1840149

Cited by 34 publications

(15 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The O 2 -dependence of H 2 O 2 generation was also demonstrated in this system. In a similar experiment, we monitored low-level chemiluminescence (Lloyd et al, 1979), characteristic of singlet O 2 (Fig. 3c).…”

Section: Resultsmentioning

confidence: 99%

“…Absorbance and light scattering measurements (Park et al, 1997) were done in a Beckmann DV 7500 UV/ visible spectrophotometer. Oxygen consumption at controlled low O 2 concentrations was in a stirred reaction vessel fitted with a Radiometer (Copenhagen) O 2 electrode in a Hitachi 557 doublebeam spectrophotometer (Degn et al, 1980) or used in an EMI single photon counting luminometer fitted with a cooled (220 uC) low-background photomultiplier tube (Lloyd et al, 1979;Biagini et al, 2001). Gas mixtures were made using pre-purified N 2 ; O 2 and solubility tables were used to calculate dissolved O 2 (Wilhelm et al, 1977).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Menadione kills trophozoites and cysts of Giardia intestinalis

et al. 2004

View full text Add to dashboard Cite

Production of reactive oxygen species by redox cycling in the presence of low levels of oxygen has been studied as a possible approach to anti-protozoal chemotherapeutic strategy. Incubation of the diplomonad flagellate Giardia intestinalis with 2-methy-1,4-naphthoquinone (menadione), under anaerobic conditions, gave UV absorption changes characteristic of reduction to menadiol; partial reversal was observed on admitting O 2 . Under microaerobic conditions, similar to those on the surface of the jejunal mucosa, trophozoites consumed O 2 rapidly in the presence of menadione; reaction products included singlet O 2 (monitored by single photon counting of O 2 -dependent low-level chemiluminescence) and H 2 O 2 (measured by the formation of Complex I of microperoxidase). Trophozoites became swollen and incapable of regulatory volume control; these irreversible responses led to loss of motility, cessation of flagellar activity and cell death. Comparison of the sensitivities of trophozoites to metronidazole and menadione gave LC 50 values (mg ml "1 ) of 1?2 and 0?7, respectively; corresponding values for cysts (measured by in vitro excystation capacities) were >50 and 1?3. Menadione (LD 50 in mice, 0?5 g kg "1 ) is therefore a potentially more useful and general anti-giardial agent than metronidazole, as it is active against cysts as well as trophozoites.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Menadione kills trophozoites and cysts of Giardia intestinalis

et al. 2004

View full text Add to dashboard Cite

show abstract

“…Hydroperoxides were used as 0. [12][13][14][15][16][17] Amol/min caused only a moderate increase in chemiluminescence, but higher rates, ,mol/min, produced a marked augmentation of light emission (Fig. 2).…”

Section: Methodsmentioning

confidence: 99%

“…On the other hand, isolated cells such as amoebae (16) and phagocytizing leukocytes (17) also have been found to be effective chemiluminescent sources.…”

mentioning

confidence: 99%

Organ chemiluminescence: noninvasive assay for oxidative radical reactions.

Boveris¹,

Cadenas²,

Reiter³

et al. 1980

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

293

171

View full text Add to dashboard Cite

In situ and perfused rat livers showed a spon- .) The existence of such light emission, which should be termed "low-level chemiluminescence" to differentiate it from the more effective photoemission of the luciferin/luciferase systems (5, 6), was soon related to oxygendependent chain reactions involving biological lipids (3-5). This early work lay fallow for years, notwithstanding the reports by Stauff and Ostrowski on the chemiluminescence of mitochondria (7) and Howes and Steele on the chemiluminescence of microsomes (8, 9), both isolated from rat liver. The more recent reports by Nakano et al. (10) and Sugioka and Nakano (11) of light emission during lipid peroxidation and other oxidative reactions (12) in microsomes revived interest in the phenomenon and suggested chemiluminescence as a tool for the investigation of the radical reactions of lipid peroxidation under physiological conditions. We have recently reported that maximal light emission in isolated mitochondria and microsomes (13) and in submitochondrial particles (14) requires an electron transfer system, hydroperoxide, and oxygen, and that hydroperoxide-supplemented cytochrome c provides a chemiluminescent model system suitable for the elucidation of some of the molecular mechanisms responsible for light emission (15). On the other hand, isolated cells such as amoebae (16) and phagocytizing leukocytes (17) also have been found to be effective chemiluminescent sources.The most important aspect of the organ chemiluminescence is that it gives readily detectable, continuously monitorable, noninvasive signals of oxidative metabolism. This article explores the possibility of continuously monitoring the metabolism of exposed or fiberoptic probed organs in vivo by the chemiluminescent technique. In this paper we report the spontaneous and hydroperoxide-induced chemiluminescence of the in situ and perfused rat liver, as well as a partial spectral analysis of the chemiluminescence of the perfused liver. Light emission seems to indicate the generation of shkrt-lived free radicals and excited states derived from the side reactions of the free radical process of lipid peroxidation. A preliminary report on light emission has been published elsewhere (13). MATERIALS AND METHODSPhoton Counting. A single-photon-counting apparatus was used (Fig. 1). Both an EMI 9658 photomultiplier, responsive in the range 300-900 nm, with an applied potential of -1.2 kV (dark current: 20-30 counts per second), and an RCA 8850 photomultiplier, responsive in the range 300-650 nm, with an applied potential of -1.8 kV (dark current: 300-400 counts per second) were used. Phototube output was connected to an amplifier-discriminator (model 1121; Princeton Applied Res., Princeton, NJ) adjusted for single photon counting and connected to both a frequency counter (Heathkit IB 1100, Heath, Benton Harbor, MI) and a recorder. The EMI phototube, cooled .down to -400C by a thermoelectric cooler (EMI-Gencom, Plainview, NY) and the RCA phototube were placed in an Ortec housing, sealed and su...

show abstract

“…6n5i10' cells ml − ") were exposed to low levels of dissolved O # in a continuously stirred reactor (200 r.p.m.) fitted with an observation window for photon counting (Lloyd et al, 1979(Lloyd et al, , 1985. The reactor was open for gas exchange from a mobile gas phase, the composition of which was controlled using a gas mixer ; dissolved O # was monitored using a Radiometer electrode.…”

Section: Measurement Of Photo-emissive O 2 -Reduction Products In Hmentioning

confidence: 99%

The antioxidant potential of pyruvate in the amitochondriate diplomonads Giardia intestinalis and Hexamita inflata

et al. 2001

View full text Add to dashboard Cite

Giardia intestinalis and Hexamita inflata are microaerophilic protozoa which rely on fermentative metabolism for energy generation. These organisms have developed a number of antioxidant defence strategies to cope with elevated O 2 tensions which are inimical to survival. In this study, the ability of pyruvate, a central component of their energy metabolism, to act as a physiological antioxidant was investigated. The intracellular pools of 2-oxo acids in G. intestinalis were determined by HPLC. With the aid of a dichlorodihydrofluorescein diacetate-based assay, intracellular reactive oxygen species generation by G. intestinalis and H. inflata suspensions was monitored on-line. Addition of physiologically relevant concentrations of pyruvate to G. intestinalis and H. inflata cell suspensions was shown to attenuate the rate of H 2 O 2 -and menadione-induced generation of reactive oxygen species. In addition, pyruvate was also shown to decrease the generation of low-level chemiluminescence arising from the oxygenation of anaerobic suspensions of H. inflata. In contrast, addition of pyruvate to suspensions of respiring Saccharomyces cerevisiae was shown to increase the generation of reactive oxygen species. These data suggest that (i) in G. intestinalis and H. inflata, pyruvate exerts antioxidant activity at physiological levels, and (ii) it is the absence of a respiratory chain in the diplomonads which facilitates the observed antioxidant activity.

show abstract

Chemiluminescence of Acanthamoeba castellanii

Cited by 34 publications

References 25 publications

Menadione kills trophozoites and cysts of Giardia intestinalis

Menadione kills trophozoites and cysts of Giardia intestinalis

Organ chemiluminescence: noninvasive assay for oxidative radical reactions.

The antioxidant potential of pyruvate in the amitochondriate diplomonads Giardia intestinalis and Hexamita inflata

Contact Info

Product

Resources

About