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Title
Enhanced glutathione S-transferase activity and glutathione content
in
human bladder cancer. Followup study: influence of smoking.
Author
Giralt M; Lafuente A; Pujol F; Mallol J
Address
Unit of Pharmacology, School of Medicine at Reus, University
of
Barcelona, Spain.
Source
J Urol, 149(6):1452-4 1993 Jun
Abstract
glutathione content and glutathione S-transferase activity have
been
studied in human bladder specimens obtained from controls and
from
patients with superficial transitional cell carcinoma (tumor
samples
and peri-tumor normal tissues from the same patient). After combining
an earlier study from our laboratory with the additional material
presented (9 healthy controls and 25 transitional cell carcinoma
patients), it can be observed that glutathione S-transferase
activity
was significantly greater in tumor than in peri-tumor normal
tissue (34
patients, p < 1 x 10(-7)) or in normal mucosa (17 controls,
p < 1 x
10(-3)). glutathione content was significantly greater in tumor
than in
peri-tumor normal tissue (p < 5 x 10(-3)) or in normal mucosa
(p < 2 x
10(-2)), with this increase being evident only in smokers. When
comparing normal mucosa and peri-tumor samples no significant
differences were found either for glutathione S-transferase activity
or
for glutathione content. Results demonstrate the relationship
between
the glutathione S-transferase/glutathione system and development
of
transitional cell carcinoma, as well as its role in cellular
resistance
to chemotherapy.
Title
glutathione content of the small intestine: regulation and function.
Author
Kelly FJ
Address
Department of Human Nutrition, University of Southampton.
Source
Br J Nutr, 69(2):589-96 1993 Mar
Abstract
In ad lib.-fed rats the epithelium of the small intestine, like
the
liver, contains large quantities of glutathione, 17.0 and 32.4
nmol/mg
protein respectively. Following 24 h food restriction the glutathione
content in both tissues fell 53 and 69% respectively. Unlike
the liver,
however, the glutathione content of the intestinal mucosa is
not
regulated to a diurnal rhythm, suggesting that the liver may
provide
glutathione or glutathione precursors to maintain intestinal
glutathione levels. Intestinal epithelial cell preparations obtained
from 24 h food-deprived rats had depleted glutathione stores
(50%) and
as a consequence were more susceptible to the oxidizing effects
of
cumene hydroperoxide. These results suggest that if glutathione
plays a
major role in the defence of the intestinal mucosa from ingested
toxins
then depletion of this defence during periods of food restriction
could
significantly increase the susceptibility of the individual to
toxins
present in the diet.
Title
Relationship between biliary excretion of bilirubin and glutathione
disulfide.
Author
Kuronuma Y; Yoshida H; Iijima M; Harada T
Address
Second Department of Internal Medicine, Dokkyo University School
of
Medicine, Tochigi, Japan.
Source
Gastroenterol Jpn, 28(2):292-7 1993 Apr
Abstract
The effects of two glutathione-oxidizing agents, t-butyl hydroperoxide
and diamide, on biliary excretion of bilirubin and glutathione
disulfide were investigated in anesthetized male Sprague-Dawley
rats.
Bilirubin (unconjugated) was infused at a constant rate of 100
nmol/kg/min through the jugular vein. When biliary excretion
of
bilirubin was stabilized, either of the glutathione-oxidizing
agents
was administered via the mesenteric vein. Biliary excretion of
glutathione disulfide increased temporarily after the administration
and returned to its basal levels within 20 min. The biliary excretion
of bilirubin decreased during the same period and returned to
the
former levels thereafter. Changes in bile flow rates remained
within
20% of the basal levels. A linear correlation was found between
the
increments in the bile concentration of glutathione disulfide
and the
decrements in that of bilirubin. Furthermore, separate experiments
revealed that reduction of hepatocellular glutathione per se
had little
effect on biliary excretion of bilirubin. The results thus indicate
that the reduction of biliary excretion of bilirubin by
glutathione-oxidizing agents was due to the increase in biliary
excretion of glutathione disulfide, and suggest that a common
biliary
excretory mechanism is shared, at least partially, by bilirubin
and
glutathione disulfide in Sprague-Dawley rats.
Title
Lung glutathione reductase induction in aging catalase-depleted
frogs
correlates with early survival throughout the life span.
Author
Perez-Campo R; Lopez-Torres M; Rojas C; Cadenas S; Barja de Quiroga
G
Address
Department of Animal Biology-II, Animal Physiology, Faculty of
Biology,
Complutense University, Madrid, Spain.
Source
Mech Ageing Dev, 67(1-2):115-27 1993 Feb
Abstract
A comprehensive experimental study on free radical-related parameters
was performed in the lung throughout the life span of 220 initially
young or old frogs. No age related differences were found transversely
or longitudinally for lung superoxide dismutase, catalase, Se-dependent
and -independent glutathione peroxidases, glutathione reductase,
GSH,
GSSG, or GSSG/GSH ratio. Continuous catalase depletion with
aminotriazole led to glutathione reductase induction in the lung
after
14.5 months of experimentation. This was accompanied by a great
increase in survival rate of treated animals in relation to controls
(especially in the old group). After 26.5 months of experimentation,
glutathione reductase induction was lost and GSSG/GSH values
tended to
increase. This was followed by a 3-month long period of acute
decrease
in survival rate of treated animals. It is suggested that a high
antioxidant/prooxidant balance is of protective value against
causes of
early death and can possibly be used in the future (when appropriately
controlled) to increase the number of healthy years of the normal
life
span.
Title
Evidence that the large loss of glutathione observed in
ischemia/reperfusion of the small intestine is not due to oxidation
to
glutathione disulfide.
Author
Gibson DD; Brackett DJ; Squires RA; Balla AK; Lerner MR; McCay
PB;
Pennington LR
Address
Molecular Toxicology Program, Oklahoma Medical Research Foundation,
Oklahoma City.
Source
Free Radic Biol Med, 14(4):427-33 1993 Apr
Abstract
Reperfusion injury following ischemia is thought to be the consequence
of reactive oxygen species possibly generated either by xanthine
oxidase activity or by processes associated with neutrophil activation
in the affected organ or tissue. The conversion of xanthine
dehydrogenase to the oxidase as well as the interactions between
endothelium and neutrophils in the margination and activation
of the
latter are all considered to be results of conditions resulting
from
the ischemic episode. Determination of the redox status of glutathione
in an ischemic/reperfused organ is frequently employed as an
indicator
of oxidative stress created by the production of oxygen free
radicals
during the reperfusion period. In this procedure, the ratio of
oxidized
glutathione (GSSG) to total glutathione (GSH + GSSG) is utilized
to
demonstrate the proportion of glutathione oxidized during reperfusion.
We determined this ratio in the rat small intestine during ischemia
and
reperfusion and found that while the ratio of GSSG/(GSH + GSSG)
does
increase, this increase was the result of GSH disappearance rather
than
an increase in GSSG, and that essentially all of this loss occurred
during the ischemic episode. We demonstrated that no oxidation
of GSH
occurred that was attributable to reperfusion per se; nor was
there an
increase of GSSG during this reoxygenation period.
Title
Changes in blood selenium and glutathione concentrations and
glutathione peroxidase activity in human pregnancy.
Author
Zachara BA; Wardak C; Didkowski W; Maciag A; Marchaluk E
Address
Department of Biochemistry, Medical School, Bydgoszcz, Poland.
Source
Gynecol Obstet Invest, 35(1):12-7 1993
Abstract
Whole-blood and plasma selenium (Se) concentrations, red blood
cell and
plasma glutathione peroxidase activities, and red blood cell
glutathione concentrations were investigated in 49 healthy pregnant
women. Mean whole-blood and red blood cell Se concentrations
started to
decline after the 16th week and plasma Se after the 26th week
of
pregnancy. The lowest values were noted just before delivery.
Negative
correlations were found between the gestational age and both
whole-blood and plasma Se concentrations: (r = -0.560 (p <
0.001) and r
= -0.553 (p < 0.001), respectively. Plasma and red blood cell
glutathione peroxidase activities started to decrease after the
20th
and 30th week of pregnancy, respectively, and before delivery
were
significantly lower (p < 0.001) than during the 10th week
of pregnancy.
The red blood cell glutathione concentration increased significantly
just before delivery. These results seem to confirm the supposition
that in pregnant women with low or even moderate blood Se
concentrations the requirement for the element significantly
increases.
Title
Differences in levels of erythrocyte glutathione and its metabolizing
enzyme activities among primates.
Author
Kurata M; Suzuki M; Takeda K
Address
Department of Veterinary Medicine, Faculty of Agriculture, Gifu
University, Japan.
Source
Comp Biochem Physiol [B], 104(1):169-71 1993 Jan
Abstract
1. The levels of erythrocyte glutathione and the activities of
its
metabolizing enzymes--glutathione peroxidase (GSH-Px), glutathione
S-transferase (GST) and glutathione reductase (GR)--were measured
in
four species of primates: human, rhesus monkey, common marmoset
and
common tree shrew. 2. There were marked differences in GSH-Px
and GST
activities among the primates, while GR activity and glutathione
level
were much less variable.
Title
Selective depletion of mitochondrial glutathione concentrations
by
(R,S)-3-hydroxy-4-pentenoate potentiates oxidative cell death.
Author
Shan X; Jones DP; Hashmi M; Anders MW
Address
Department of Biochemistry, Emory University, Atlanta, Georgia
30322.
Source
Chem Res Toxicol, 6(1):75-81 1993 Jan-Feb
Abstract
The hepatocellular glutathione content is partitioned into a
cytosolic
pool, which accounts for about 85% of the cellular glutathione
content,
and a mitochondrial pool, which accounts for about 15% of the
cellular
glutathione content. Previous studies indicated that the mitochondrial
glutathione pool may play a critical role in cytoprotection against
xenobiotic-induced cell damage. Tests of the role of mitochondrial
glutathione in cytoprotection have been hampered by the lack
of agents
that selectively deplete the mitochondrial glutathione pool.
To test
the hypothesis that mitochondrial glutathione plays a critical
role in
protecting against cytotoxic agents, we developed a method to
deplete
selectively mitochondrial glutathione concentrations.
(R,S)-3-Hydroxy-4-pentenoate, an analog of (R)-3-hydroxybutanoate,
caused a rapid and selective depletion of mitochondrial glutathione
concentrations. Incubation of (R,S)-3-hydroxy-4-pentenoate with
rat
liver mitochondria or with 3-hydroxybutyrate dehydrogenase in
the
presence of glutathione afforded a glutathione conjugate whose
chromatographic properties were identical with synthetic
S-(3-oxo-4-carboxybutyl)glutathione, indicating that
(R,S)-3-hydroxy-4-pentenoate was oxidized to the Michael acceptor
3-oxo-4-pentenoate, which reacts with glutathione. Exposure of
rat
hepatocytes to (R,S)-3-hydroxy-4-pentenoate, which was not cytotoxic
and did not induce mitochondrial dysfunction, potentiated the
cytotoxicity of tert-butyl hydroperoxide. These results establish
the
critical role of mitochondrial glutathione in cytoprotection
and
demonstrate and (R,S)-3-hydroxy-4-pentenoate may find utility
in
exploring mitochondrial glutathione homeostasis.
Title
glutathione peroxidase, glial cells and Parkinson's disease.
Author
Damier P; Hirsch EC; Zhang P; Agid Y; Javoy-Agid F
Address
INSERM U 289, Hôpital de la Salpêtrière, Paris,
France.
Source
Neuroscience, 52(1):1-6 1993 Jan
Abstract
Hyperoxidation phenomena are suspected to be involved in dopaminergic
cell death in Parkinson's disease, which affects preferentially
the
neuromelanin-containing dopaminergic neurons of the substantia
nigra.
glutathione peroxidase is the major protective enzyme against
hydrogen
peroxide toxicity. The distribution of glutathione
peroxidase-containing cells was investigated by immunohistochemistry
in
the midbrain of four control subjects and four patients with
Parkinson's disease. (1) glutathione peroxidase-like immunoreactivity
was detected exclusively in glial cells. (2) In control brains,
the
density of glutathione peroxidase-positive cells was higher in
the
vicinity of the dopaminergic cell groups known to be resistant
to the
pathological process of Parkinson's disease. (3) In Parkinson's
disease, an increased density of glutathione peroxidase-immunostained
cells was observed, surrounding the surviving dopaminergic neurons.
The
increase in glutathione peroxidase-containing cells was correlated
with
the severity in dopaminergic cell loss in the respective cell
groups.
The data suggest that in control brains, a low density of glutathione
peroxidase-positive cells surround the dopaminergic neurons the
most
vulnerable to Parkinson's disease, and that in parkinsonian brains,
the
increased number of glutathione peroxidase-positive cells may
contribute to protect neurons against pathological death. Thus,
the
amount of glutathione peroxidase protein-containing cells may
be
critical for a protective effect against oxidative stress, although
it
cannot be excluded that the level of the enzyme activity remains
the
crucial factor.
Title
A simple technique to determine glutathione (GSH) levels and
synthesis
in ocular tissues as GSH-bimane adduct: application to normal
and
galactosemic guinea-pigs.
Author
Kannan R; Tang D; Mackic JB; Zlokovic BV; Fernandez-Checa JC
Address
Division of Gastrointestinal and Liver Diseases, Children's Hospital
of
Los Angeles, University of Southern California School of Medicine.
Source
Exp Eye Res, 56(1):45-50 1993 Jan
Abstract
A fluorimetric technique previously described for other tissues
has
been applied to determine levels of glutathione and its synthetic
rates
in ocular tissues of Hartley guinea-pigs. Monochlorobimane forms
a
stable, fluorescent adduct with glutathione in a reaction catalyzed
by
glutathione-S-transferase. The fluorescent signal recorded over
time is
directly proportional to the synthetic rate of glutathione. Lens,
cornea and retina were homogenized and cytosolic fractions dialyzed
overnight to deplete endogeneous glutathione. glutathione synthetic
rates were determined from a mixture of glutathione precursors
and
co-factors, viz. cysteine+dithiothreitol, glutamic acid+glycine,
ATP and
Mg++ in the presence of monochlorobimane. The mixture was supplemented
with glutathione-S-transferase to catalyze the formation of the
fluorescent adduct. glutathione synthetic rates were determined
in the
absence and presence of buthionine sulfoximine, an inhibitor
of
gamma-glutamyl cysteine synthetase. The difference in fluorescence
change over time in the presence and absence of buthionine sulfoximine
was used to estimate glutathione synthesis. Basal levels of glutathione
in pre-dialyzed cytosolic fractions of the lens, cornea, and
retina
were 21.8 +/- 2.2, 36.5 +/- 4.1 and 38.6 +/- 2.8 nmol mg-1 protein,
respectively. The maximal glutathione synthetic rates in these
tissues
were 0.52 +/- 0.04, 2.25 +/- 0.67 and 3.35 +/- 0.65 nmol min-1
mg-1
protein, respectively. When gamma-glutamyl cysteine is used as
a
precursor instead of cysteine, the glutathione synthetase activities
from lenses and retinas were 0.19 +/- 0.08 and 1.54 +/- 0.76
nmol-1 min
mg-1 protein.(Abstract TRUNCATED AT 250 WORDS)
Title
Buthionine sulfoximine reduces the protective capacity of myocytes
to
withstand peroxide-derived free radical attack.
Author
Le CT; Hollaar L; van der Valk EJ; van der Laarse A
Address
Department of Cardiology, University Hospital, Leiden, The Netherlands.
Source
J Mol Cell Cardiol, 25(5):519-28 1993 May
Abstract
Mammalian heart myocytes have a limited capacity to withstand
the
deleterious effects of free radical generating compounds. To
assess the
role of the glutathione redox cycle relative to this capacity,
rat
heart cell cultures were subjected for 90 min to 80 mumol/l cumene
hydroperoxide (CHPO) without and with prior glutathione depletion
by
buthionine sulfoximine. Preincubation of cultures with 125 mumol/l
buthionine sulfoximine for 2 h and 17 h caused a reduction of
glutathione by 33% and 82%, respectively, without concomitant
increase
of glutathione disulfide. Subsequent incubation with CHPO for
90 min
caused slowing of NADPH consumption (in the first 20 min 27 pmol
vs 68
pmol without pretreatment with buthionine sulfoximine for 17
h), which
indicates that glutathione depletion reduced the turnover rate
of the
glutathione redox cycle. Pretreatment with buthionine sulfoximine
for
17 h exaggerated the negative chronotropic effects of CHPO: the
time
elapsed to 50% of baseline contraction frequency fell from 5.7
+/- 1.4
min without buthionine sulfoximine to 3.7 +/- 0.4 min after
pretreatment with buthionine sulfoximine (P < 0.02). The severity
of
CHPO-induced lipid peroxidation as assessed by malondialdehyde
formation (2.23 +/- 0.51 vs 0.99 +/- 0.05 nmol in the first 20
min; P <
0.05) was increased by buthionine sulfoximine pretreatment, as
was the
extent of cell necrosis as assessed by release of alpha-hydroxybutyrate
dehydrogenase (39.5 +/- 5.1 vs 29.0 +/- 12.9% in the first 45
min). A
"sublethal" dose of 10 microM CHPO for 60 min caused
no substantial
HBDH release, no formation of malondialdehyde, and no exhaustion
of
cellular GSH (35 nmol/U HBDHt = 0). However, following pretreatment
with buthionine sulfoximine, 10 microM CHPO for 60 min produced
12%
HBDH release and extensive lipid peroxidation (1.95 nmol
malondialdehyde/U HBDHt = 0). As the deleterious effects of CHPO
were
aggravated by glutathione depletion, we conclude that the glutathione
redox cycle plays a major role in the protection of myocytes
against
peroxide-induced free radical attack.
Title
glutathione peroxidase protects cultured mammalian cells from
the
toxicity of adriamycin and paraquat.
Author
Taylor SD; Davenport LD; Speranza MJ; Mullenbach GT; Lynch RE
Address
Department of Pathology, University of Utah School of Medicine,
Salt
Lake City.
Source
Arch Biochem Biophys, 305(2):600-5 1993 Sep
Abstract
Dihydrofolate reductase-minus mutants of Chinese hamster ovary
cells
were depleted of glutathione peroxidase by transcription of the
transfected bovine cDNA in inverted orientation upstream from
the cDNA
for dihydrofolate reductase to engender a bicistronic mRNA. In
a clone
of cells selected for expression of dihydrofolate reductase by
the
ability to grow in nucleoside-free medium the activity of glutathione
peroxidase was reduced to 20% of the activity in the untransfected
parental line of cells (DG44). The cells depleted of glutathione
peroxidase were more sensitive to the toxicities of paraquat
and
adriamycin than the untransfected parental cells from which they
derived but not more sensitive to bleomycin, menadione, or phenazine
methosulfate. That the mildly increased sensitivity to paraquat
and
adriamycin was the consequence of the diminished cellular content
of
glutathione peroxidase was confirmed by the increase in sensitivity
of
untransfected cells after treatment with buthionine sulfoximine,
an
agent which depletes cells of glutathione. These and other data
strongly suggest that the enzymic action of glutathione peroxidase
protects cells from the toxicity of paraquat and adriamycin.
The toxin
which these agents engender is likely to be hydrogen peroxide
or
another hydroperoxide upon which glutathione peroxidase acts.
Title
The effect of glutathione depletion on methyl mercury-induced
microtubule disassembly in cultured embryonal carcinoma cells.
Author
Graff RD; Philbert MA; Lowndes HE; Reuhl KR
Address
Department of Pharmacology and Toxicology, College of Pharmacy,
Rutgers
University, Piscataway, New Jersey 08855-0789.
Source
Toxicol Appl Pharmacol, 120(1):20-8 1993 May
Abstract
Microtubule (MT) assembly and stability are thought to be dependent
on
intracellular glutathione for the maintenance of critical sulfhydryl
groups. Since methyl mercury (MeHg) is a sulfhydryl-binding toxicant,
it is possible that alteration of intracellular glutathione status
might enhance the toxic effects of MeHg on microtubules. The
influence
of MeHg on the relationship between intracellular glutathione
and the
structural integrity of interphase microtubules was assessed
in
embryonal carcinoma cells by immunofluorescence microscopy, using
antibodies to tyrosinated and acetylated alpha-tubulins. Intracellular
glutathione concentrations were reduced by treatment with 10
microM
buthionine sulfoximine (BSO; an inhibitor of gamma-glutamyl cysteine
synthetase) for 18-24 hr. BSO-treated cells displayed little
change in
the pattern of microtubule staining, despite reduction of glutathione
levels to less than 10% of control levels. Similarly, a combination
of
BSO and the nonspecific glutathione-depleting agent diethylmaleimide
(DEM) had little effect on microtubule networks, except at the
highest
concentrations of DEM where nonspecific cytotoxicity was observed.
The
susceptibility of microtubules to MeHg-induced disassembly was
determined in normal and glutathione-depleted cells incubated
with 1.0
to 7.5 microM MeHg for 2 hr. MeHg treatment alone resulted in
concentration-dependent disassembly of microtubules; depletion
of
glutathione with BSO prior to MeHg treatment did not enhance
MT damage.
Further, BSO-pretreated cells exposed to MeHg still showed substantial
recovery of microtubule networks following removal of MeHg from
culture
media, even when glutathione levels remained less than 5% of
control
levels. These data indicate that the integrity of interphase
microtubules is largely unaffected by reductions in glutathione
concentration and that susceptibility of microtubules to MeHg-induced
disassembly is not directly dependent on intracellular glutathione
content.
Title
Characteristics of the glutathione/glutathione-S-transferase
detoxification system in melphalan resistant human prostate cancer
cells.
Author
Ripple M; Mulcahy RT; Wilding G
Address
Department of Human Oncology, University of Wisconsin Clinical
Cancer
Center, Madison.
Source
J Urol, 150(1):209-14 1993 Jul
Abstract
glutathione (GSH) and glutathione-S-transferases (GST) have been
implicated in resistance of tumor cells to certain alkylating
agents,
including melphalan. glutathione levels and GST activities were
determined in melphalan-resistant sublines of the human prostate
carcinoma cell lines DU 145, PC-3 and LNCaP produced by serial
treatment with melphalan at progressively increasing concentrations.
The resistant sublines M4.5DU145, M5DU145, M6DU145, M6PC-3 and
M6LNCaP
were 27-, 7-, 3-, 6- and 2-fold more resistant to melphalan than
the
parental lines. The melphalan-resistant DU 145 and PC-3 lines
showed
cross-resistance to cisplatin and tetraplatin, but retained sensitivity
to vinblastine, colchicine and etoposide. Interestingly, both
sublines
were also resistant to methotrexate and adriamycin. The
melphalan-resistant LNCaP line showed slight resistance to cisplatin
and adriamycin, but remained sensitive to tetraplatin and methotrexate.
This line also retained sensitivity to vinblastine while developing
resistance to colchicine. Intracellular GSH levels were increased
2.8
fold for M5DU145, 1.7 fold for M6PC-3 and 2.1 fold for M6LNCaP
compared
to the parental lines, whereas GST activity using chlorodinitro-benzene
as a substrate was comparable for all lines. When cumene hydroperoxide
was used as a substrate, an increase in GST activity was noted
only in
the M6PC-3 line as compared with the parent line. Western blot
analysis
showed no change in GST isozyme profile between parent and resistant
DU
145 lines; however a mu class isoenzyme was detected in the resistant,
but not in the parent PC-3 line, using a Yb1 antibody. M5DU145
cells
maintained in the absence of melphalan for seven months maintained
their resistance to melphalan. Depletion of GSH, with buthionine
sulfoximine, to control levels reversed melphalan resistance
to control
levels. |
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