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Title
Effect of cigarette smoke and its condensates on alveolar epithelial
cell inJury in vitro.
Author
Lannan S; Donaldson K; Brown D; MacNee W
Address
Department of Medicine' City Hospital and Napier University'
Edinburgh'
Scotland' United Kingdom.
Source
Am J Physiol, 266(1 Pt 1):L92-100 1994 Jan
Abstract
The oxidant-antioxidant balance in the airspaces of the lungs
may be
critical in protecting the lungs from the effects of cigarette
smoke.
We studied the effect of cigarette smoke and its condensates
on the
detachment' attachment' and proliferation of the A549 human alveolar
epithelial cell line' in an in vitro model of cell inJury and
regeneration and the protective effects of antioxidants. Whole
and
vapor phase cigarette smoke decreased 51Cr-labeled A549 cell
attachment' increased cell detachment' and decreased cell
proliferation' as assessed by [3H thymidine uptake. Freshly isolated
rat type II alveolar epithelial cells showed an enhanced susceptibility
to smoke-induced cell lysis when compared with the A549 cell
line.
Reduced glutathione (GSH) (400 microM) protected against the
effects of
cigarette smoke exposure on cell attachment' proliferation' and
detachment. Depletion of intracellular GSH with buthionine sulfoxamine
enhanced the epithelial cell detachment inJury produced by smoke
condensates. We conclude that cigarette smoke and its condensates
cause
an oxidant-induced inJury to A549 human type II alveolar epithelial
cells. Both intra- and extracellular GSH have important roles
in
protecting epithelial cells from the inJurious effects of cigarette
smoke.
Title
Chemopreventive activity of thiol conjugates of isothiocyanates
for
lung tumorigenesis.
Author
Jiao D; Smith TJ; Yang CS; Pittman B; Desai D; Amin S; Chung
FL
Address
Division of Carcinogenesis and Molecular Epidemiology, American
Health
Foundation, Valhalla, NY 10595, USA.
Source
Carcinogenesis, 18(11):2143-7 1997 Nov
Abstract
A series of L-cysteine (L-Cys), glutathione (GSH), and
N-acetyl-L-cysteine (NAC) conjugates of phenethyl (PEITC), benzyl
(BITC), and 6-phenylhexyl isothiocyanate (PHITC) were studied
for their
inhibitory activity toward metabolic activation of the tobacco-specific
nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)
in
mouse lung microsomes. Selected compounds, PEITC, PEITC-GSH,
PEITC-NAC
and PHITC-NAC, were also assayed for the potential chemopreventive
activity toward NNK-induced lung tumorigenesis in A/J mice. Results
showed that PEITC and its conjugates inhibited NNK metabolism
with
decreasing potency: PEITC < PEITC-GSH > PEITC-Cys >
PEITC-NAC. PHITC
and its GSH and NAC conjugates exhibited nearly 10 times higher
inhibitory activity toward NNK metabolism than the PEITC counterparts.
In the tumor bioassay, as expected, the conjugates exhibited
inhibitory
activity against lung tumorigenesis induced by NNK. PEITC-GSH
was not
inhibitory at 4 micromol/mouse, but it inhibited approximately
32% of
lung tumor multiplicity at 8 micromol/mouse. PEITC-NAC at 5 and
20
micromol/mouse both inhibited approximately 30% tumor multiplicity.
Among all the conjugates examined, PHITC-NAC was the most potent.
At a
5-micromol dose, it completely inhibited tumor multiplicity and
incidence to the background level observed in the control group.
These
results revealed that the structure-activity relationships of
the
conjugates are similar to those found with their parent isothiocyanates
(ITCs), i.e., the potency increased with the increasing alkyl
chain
length from two to six carbons in arylalkyl ITCs, suggesting
that a
common active species is involved. The inhibitory activity of
ITC
conjugates and the expected low toxicity make thiol conjugates
of ITC a
promising new series of chemopreventive agents.
Title
Antioxidative enzyme activities in human erythrocytes.
Author
Andersen HR; Nielsen JB; Nielsen F; GrandJean P
Address
Department of Environmental Medicine' Odense University' Denmark.
HR.ANDERSEN@Winsloew.OU.DK
Source
Clin Chem, 43(4):562-8 1997 Apr
Abstract
Reliable and standardized methods are necessary to determine
the
expression of antioxidative enzymes and their role in maintaining
health. In addition' the variability of the enzyme activities
within
the general population caused by age' gender' and life-style
factors
must be described. This study describes methodological conditions
that
are suitable for analyzing copper-zinc superoxide dismutase (CuZn-SOD)'
glutathione peroxidase (GSH-Px)' catalase (CAT)' and glutathione
reductase (GR) in human erythrocytes with a high degree of
reproducibility. Intervals for the enzyme activities have been
established in a randomly selected population of 220 individuals
between 20 and 89 years of age. An age-related decrease was observed
in
CuZn-SOD and GR activities' whereas no age-related changes were
demonstrated for GSH-Px and CAT. The GSH-Px activity was positively
associated with the intake of dietary supplements and negatively
correlated with tobacco consumption. These factors probably account
for
the fact that women tended to have higher GSH-Px activity.
Title
Anti-oxidant enzymes' gamma-glutamyl transpeptidase and lipid
peroxidation in kidney of rats exposed to cigarette smoke.
Author
Anand CV; Anand U; Agarwal R
Address
Department of Biochemistry' MS Ramaiah Medical College' Bangalore'
India.
Source
Indian J Exp Biol, 34(5):486-8 1996 May
Abstract
glutathione reductase (GR)' glutathione peroxidase (GSH Px) and
catalase (Cat) were determined in the kidneys of rats exposed
to
cigarette smoke for 3 months. Activity of the brush-border enzyme
gamma-glutamyl transpeptidase (GGT)' glutathione (GSH) and lipid
peroxide levels (LPX) were also estimated in both' kidney homogenates
and urine. Activities of GR' Cat' GGT and the levels of GSH were
decreased in the kidney. However' the activities of GSH Px and
LPX
levels were increased. Urinary excretion of GGT' GSH and LPX
were also
higher. Fall in the activity of GR and rise in the activity of
GSH Px'
may perturb the reduced glutathione/oxidised glutathione ratio'
which
in turn could lead to increased LPX seen in chronic cigarette
smoke
exposure.
Title
The effect of acute cigarette smoke inhalation on pulmonary and
systemic cysteine and glutathione redox states in the rat.
Author
Cotgreave IA; Johansson U; Moldéus P; Brattsand R
Source
Toxicology, 45(2):203-12 1987 Aug
Abstract
Inhalation of tobacco smoke (TS) by rats for 1 h caused significant
depletions in the free glutathione (GSH) of homogenate supernatants
of
whole lung (13.9-8.8 mumol/g protein), lavage cells (2.7-1.7
nmol/10(6)
cells) and lavage fluid (1.3-0.4 microM). In each case the depletions
were nonrecoverable by dithiothreitol (DTT) suggesting conjugation
between GSH and TS-borne electrophiles. Corresponding lung cysteine
(CySH) components were unaffected by TS inhalation. In contrast,
TS
inhalation had no effect on the blood plasma GSH redox balance
at
various points around the circulation, but was shown to affect
those of
CySH, causing significant reductions in total CySH in plasma
samples
obtained both pre- and postpulmonarily. Similarly, the redox
status of
GSH in homogenate supernatants of whole liver was unaffected
by TS
inhalation, but there were significant increases in hepatic free
CySH.
These results indicate that acute TS inhalation increases the
oxidant
burden on the lungs causing a transient depletion of GSH in a
variety
of pools. Concurrently, the lungs may possess regulatory mechanism(s)
which respond immediately by the uptake of CySH equivalents present
in
plasma disulfides.
Title
Cadmium-enriched cigarette smoke-induced cytological and biochemical
alterations in rat lungs.
Author
Gairola CG
Address
tobacco and Health Research Institute, University of Kentucky,
Lexington 40546-0236.
Source
J Toxicol Environ Health, 27(3):317-29 1989
Abstract
Male Sprague-Dawley rats were exposed daily for 52 wk in a nose-only
exposure system to smoke from the University of Kentucky 2R1
reference
cigarettes (SM) or from cigarettes made of cadmium-enriched tobacco
(Cd-SM). At sacrifice, the animals were evaluated by bronchoalveolar
lavage (BAL) for inflammatory cell response in the lungs, and
the cells
so obtained were analyzed for phagocytosis of particles (latex
and
IgG-coated SRBCs) and for their ability to release oxidants upon
phagocytic challenge. Additionally, lung tissues were analyzed
for Cd
levels and lung homogenate fractions were assayed for aryl hydrocarbon
hydroxylase (AHH) as well as total and selenium-dependent glutathione
peroxidase (GSH-Px) activities. BAL cell counts showed a significant
influx of inflammatory cells into the lungs of the Cd-SM group
but not
the SM group. The proportion of neutrophils in the BAL cells
of the
Cd-SM group was elevated to 40 +/- 9%, compared with less than
2% in
the SM group. Phagocytosis of both types of particles by macrophages
from SM and Cd-SM groups was similar to that of the control groups,
except that a greater uptake of latex particles was seen in Cd-SM
macrophages. The release of oxidants (superoxides and hydrogen
peroxide) by the BAL cells was severely impaired in the Cd-SM
group,
whereas a slight stimulation was seen in the SM group. Pulmonary
GSH-Px
activity was the same in all groups. A significant induction
of the
pulmonary AHH activity was observed in the SM group only. The
Cd levels
in the lungs were approximately 8- and 200-fold greater than
controls
in SM and Cd-SM groups, respectively. These observations suggest
a
significant influence of tobacco Cd on the toxicity of cigarette
smoke.
Title
Red cell reduced glutathione and tobacco smoke-induced optic
neuropathy.
Author
Costagliola C; Cotticelli L; Menzione M; Rinaldi M; Russo S;
Rinaldi E
Address
Eye Clinic' First School of Medicine' University of Naples' Italy.
Source
Metab Pediatr Syst Ophthalmol, 13(2-4):96-8 1990
Abstract
Cigarette smoke contains detectable amounts of cyanide' regardless
of
the type of cigarette. The very high levels of this compound
in plasma
of amblyopic smokers suggests that cyanide causes optic neuropathy.
The
detoxification of cyanide in man occurs through various metabolic
pathway; the most important are those that use sulfur to transform
cyanide into thiocyanate. One of the richest sources of reduced
sulfhydryl groups is reduced glutathione (GSH). For this reason
we
investigated red cell GSH levels in non-smokers' in healthy smokers
and
in smokers affected by optic neuropathy to ascertain whether
this
compound is a marker of the disease. Red cell GSH levels in the
non-smokers group were similar to those of affected smokers.
On the
contrary' GSH levels in healthy smokers were significantly more
elevated. During therapy with vitamin E we noted that the concentration
of GSH decreased with the progression of the disease and increased
with
recovery. Moreover' there was a good correlation between GSH
levels and
clinical findings. Our findings demonstrate that GSH plays a
key role
in the detoxification of cyanide and so it could be a marker
of tobacco
smoke-induced optic neuropathy.
Title
glutathione homeostasis in alveolar epithelial cells in vitro
and lung
in vivo under oxidative stress.
Author
Rahman I; Li XY; Donaldson K; Harrison DJ; MacNee W
Address
Rayne Laboratory' Department of Medicine' University of Edinburgh'
United Kingdom.
Source
Am J Physiol, 269(3 Pt 1):L285-92 1995 Sep
Abstract
We studied the acute effects of cigarette smoke condensate (CSC)'
H2O2'
and tumor necrosis factor (TNF)-alpha on the glutathione (GSH)
redox
system in a human type II epithelial cell line (A549) in vitro.
CSC' in
vitro and in vivo after intratracheal instillation of CSC in
the rat'
produced a depletion of intracellular soluble GSH' concomitant
with
GSH-conJugate formation' without significant elevation of oxidized
GSH
(GSSG)' protein-GSH mixed disulfides (PrSSG)' nor any GSH efflux
from
the cells. By contrast' H2O2 (500 microM) after 5-min exposure
to A549
cells caused significant depletion of intracellular GSH associated
with
an efflux of GSSG and a significant increase in the formation
of PrSSG.
TNF-alpha' in concentrations of 100 U/ml and 1'000 U/ml' produced
a
significant depletion of GSH in A549 cells after 4- and 24-h
exposure'
with an associated elevation of GSSG. The activities of glutathione
peroxidase' gamma-glutamylcysteine synthetase' and glucose-6-phosphate
dehydrogenase were significantly decreased in epithelial cells
and in
rat lungs after CSC exposure' without change in glutathione
S-transferase and glutathione reductase activities. By contrast'
H2O2
and TNF-alpha did not alter these enzyme activities in epithelial
cells. Thus GSH depletion and alteration in enzyme activities
in
alveolar epithelial cells by CSC' H2O2' and TNF-alpha occur by
different mechanisms.
Title
Oxidative damage in chemical teratogenesis.
Author
Wells PG; Kim PM; Laposa RR; Nicol CJ; Parman T; Winn LM
Address
Faculty of Pharmacy, University of Toronto, Ont., Canada.
pg.wells@utoronto.ca
Source
Mutat Res, 396(1-2):65-78 1997 Dec 12
Abstract
The teratogenicity of many xenobiotics is thought to depend at
least in
part upon their bioactivation by embryonic cytochromes P450,
prostaglandin H synthase (PHS) and lipoxygenases (LPOs) to
electrophilic and/or free radical reactive intermediates that
covalently bind to or oxidize cellular macromolecules such as
DNA,
protein and lipid, resulting in in utero death or teratogenesis.
Using
as models the tobacco carcinogens benzo[a pyrene (B[a P) and
4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), the
anticonvulsant drug phenytoin, structurally related anticonvulsants
(e.g. mephenytoin, nirvanol, trimethadione, dimethadione) and
the
sedative drug thalidomide, we have examined the potential teratologic
relevance of free radical-initiated, reactive oxygen species
(ROS)-mediated oxidative molecular target damage, genotoxicity
(micronucleus formation) and DNA repair in mouse and rabbit models
in
vivo and in embryo culture, and in vitro using purified enzymes
or
cultured rat skin fibroblasts. These teratogens were bioactivated
by
PHS and LPOs to free radical reactive intermediary metabolites,
characterized by electron spin resonance spectrometry, that initiated
ROS formation, including hydroxyl radicals, which were characterized
by
salicylate hydroxylation. ROS-initiated oxidation of DNA
(8-hydroxy-2'-deoxyguanosine formation), protein (carbonyl formation),
glutathione (GSH) and lipid (peroxidation), and embryotoxicity
were
shown for phenytoin, its major hydroxylated metabolite
5-(p-hydroxyphenyl)-5-phenylhydantoin [HPPH , thalidomide, B[a
P and
NNK in vivo and/or in embryo culture, the latter indicating a
teratologically critical role for embryonic, as distinct from
maternal,
processes. DNA oxidation and teratogenicity of phenytoin and
thalidomide were reduced by PHS inhibitors. Oxidative macromolecular
lesions and teratogenicity also were reduced by the free radical
trapping agent phenylbutylnitrone (PBN), and the antioxidants
caffeic
acid and vitamin E. In embryo culture, addition of superoxide
dismutase
(SOD) to the medium enhanced embryonic SOD activity, and SOD
or
catalase blocked the oxidative lesions and embryotoxicity initiated
by
phenytoin and B[a P, suggesting a major contribution of ROS,
as
distinct from covalent binding, to the teratologic mechanism.
In in
vivo studies, other antioxidative enzymes like GSH peroxidase,
GSH
reductase and glucose-6-phosphate dehydrogenase (G6PD) were similarly
protective. Even untreated G6PD-deficient mice had enhanced
embryopathies, indicating a teratological role for endogenous
oxidative
stress. In cultured fibroblasts, B[a P, NNK, phenytoin and HPPH
initiated DNA oxidation and micronucleus formation, which were
inhibited by SOD. Oxidation of DNA may be particularly critical,
since
transgenic mice with +/- or -/- deficiencies in the p53 tumor
suppressor gene, which facilitates DNA repair, are more susceptible
to
phenytoin and B[a P teratogenicity. Even p53-deficient mice treated
only with normal saline showed enhanced embryopathies, suggesting
the
teratological importance of endogenous oxidative stress, as observed
with G6PD deficiency. These results suggest that oxidative
macromolecular damage may play a role in the teratologic mechanism
of
xenobiotics that are bioactivated to a reactive intermediate,
as well
in the mechanism of embryopathies occurring in the absence of
xenobiotic exposure.
Title
Oxidative damage and antioxidant status in the lungs and
bronchoalveolar lavage fluid of rats exposed chronically to cigarette
smoke.
Author
Wurzel H; Yeh CC; Gairola C; Chow CK
Address
Graduate Center for Toxicology' College of Pharmacy' University
of
Kentucky' Lexington 40506-0054' USA.
Source
J Biochem Toxicol, 10(1):11-7 1995 Feb
Abstract
The effect of chronic smoke exposure on oxidative damage and
antioxidant status was studied in rats. Ten-week-old female
Sprague-Dawley rats were exposed to fresh mainstream cigarette
smoke or
filtered room air twice daily' or maintained as room controls'
for 65
weeks. Animals were sacrificed 18-20 hours after the last treatment.
The bronchoalveolar lavage (BAL) fluid' lung tissues' and plasma
were
processed to assess oxidative damage and antioxidant status.
Compared
with sham and room control groups' the levels of conJugated dienes
and
alpha-tocopheryl quinone were significantly higher in the lung
tissues
of rats exposed to cigarette smoke. The levels of malondialdehyde'
protein carbonyls' reduced glutathione (GSH)' ascorbic acid and
vitamin
E' and activities of catalase and GSH peroxidase in the lung
tissues
were not significantly altered by smoke exposure. No significant
differences in any measurements were found in BAL fluid and plasma
among the experimental groups. The results obtained support the
view
that cigarette Smoking increases oxidative stress and suggest
a
metabolic adaptation of antioxidant systems following chronic
smoke
exposure.
Title
Arabidopsis thaliana gamma-glutamylcysteine synthetase is structurally
unrelated to mammalian' yeast' and Escherichia coli homologs.
Author
May MJ; Leaver CJ
Address
Department of Plant Sciences' University of Oxford' United Kingdom.
Source
Proc Natl Acad Sci U S A, 91(21):10059-63 1994 Oct 11
Abstract
A mutant of Escherichia coli' JTG10' deficient in
gamma-glutamylcysteine synthetase (gamma-ECS; EC 6.3.2.2) is
unable to
synthesize glutathione (GSH) and is sensitive to 8-hydroxyquinoline.
This phenotype was exploited for the isolation of Arabidopsis
thaliana
gamma-ECS cDNAs by expression cloning' and clones were selected
through
functional complementation by growth on 8-hydroxyquinoline. High
levels
of gamma-ECS activity were detectable in extracts derived from
cultures
of JTG10 expressing the Arabidopsis gamma-ECS open reading frame'
although these complemented mutants accumulated GSH to only 10%
of the
wild-type level. The derived amino acid sequence constitutes
a
polypeptide of 59.9 kDa and shows only 44-48% similarity with
previously published sequences of rat kidney' human liver' yeast'
and
E. coli gamma-ECS. When the gamma-ECS cDNA was used as a probe'
Southern blot analysis of Arabidopsis genomic DNA revealed that
it is
present as a low copy number gene. Furthermore' the Arabidopsis
gamma-ECS cDNA probe failed to hybridize to maize and tobacco
genomic
DNA at low stringency' suggesting that heterogeneity in gamma-ECS
structure exists between plant species. The activity of recombinant
Arabidopsis gamma-ECS was inhibited by buthionine sulfoximine
and GSH'
indicating that' while differences in the primary and secondary
structure of gamma-ECS from different sources exist' the enzymes
may
have similar active site structures.
Title
Dietary vitamin E and pulmonary biochemical responses of rats
to
cigarette Smoking.
Author
Chow CK; Chen LH; Thacker RR; Griffith RB
Source
Environ Res, 34(1):8-17 1984 Jun
Abstract
The effect of dietary vitamin E on cellular susceptibility to
cigarette
Smoking was studied in rats. Young male rats maintained on a
basal
vitamin E-deficient diet with or without 100 ppm vitamin E
supplementation for 4 or 5 weeks were exposed to either sham
or
cigarette smoke for up to 7 days. Higher animal mortality rate
was
observed in the animals fed the vitamin E-deficient diet than
in the
supplemented group when they were subJected to acute levels of
cigarette Smoking. Relative to the respective sham groups' a
greater
alteration of biochemical parameters' such as reduced glutathione
(GSH)
and related enzymes' was found in the lungs of smoked rats fed
the
deficient diet than in the supplemented group. Animal lungs exhibited
a
greater biochemical response to whole smoke than the gaseous
phase of
smoke. The results suggest that the nutritional status of vitamin
E may
influence the cellular susceptibility of rats to cigarette Smoking. |
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