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Date: Thu, 10 Oct 1996 13:02:57 -0600
To: Kate Hallberg <[log in to unmask]>
From: Kate Hallberg <[log in to unmask]>
Subject: bilirubin and free radical scavenging
Jaundice….
*****ARCHIVES INTERNATIONALES DE PHYSIOLOGIE ET DE BIOCHIMIE*****
(REFERENCE 1 OF 23)
74021242
Bonnett R Stewart JC
On the photo-oxidation of bilirubin in methanol.
In: Arch Int Physiol Biochim (1972 Dec) 80(5):951-2
[No Abstract Available]
*****BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS*****
(REFERENCE 2 OF 23)
95398622
Yamaguchi T Horio F Hashizume T Tanaka M Ikeda S Kakinuma A
Nakajima H
Bilirubin is oxidized in rats treated with endotoxin and acts as a
physiological antioxidant synergistically with ascorbic acid in vivo.
In: Biochem Biophys Res Commun (1995 Sep 5) 214(1):11-9
We examined the possibility that bilirubin physiologically acts as an
antioxidant by using scurvy-prone ODS-od/od rats treated with
endotoxin (lipopolysaccharide: LPS). Recently, bilirubin oxidative
metabolites were isolated from human urine and named biotripyrrin-a
and biotripyrrin-b. The LPS injection markedly increased bilirubin
oxidative metabolites in urine of rats fed an ascorbic acid-free
diet. This increase was supressed by feeding an adequate amount of
ascorbic acid, a physiological antioxidant. the concentrations of
biotripyrrin-a and -b in urine collected 6.5-10 h after the LPS
injection were lower in rats fed an ascorbic acid-supplemented diet
than in rats fed an ascorbic acid-free diet. Moreover, feeding with
ascorbic acid suppressed the elevation of hepatic mRNA level of heme
oxygenase-1, the rate-limiting enzyme of bilirubin biosynthesis, in
rats injected with LPS. These findings suggest that bilirubin is
oxidized in rats treated with LPS and acts as a physiological
antioxidant synergistically with ascorbic acid in vivo.
Institutional address:
Department of Biochemical Genetics
Tokyo Medical and Dental University
Japan.
*****BIOCHEMISTRY AND CELL BIOLOGY*****
(REFERENCE 3 OF 23)
92189753
Wu TW Wu J Li RK Mickle D Carey D
Albumin-bound bilirubins protect human ventricular myocytes against
oxyradical damage.
In: Biochem Cell Biol (1991 Oct-Nov) 69(10-11):683-8
Synthetic delta-bilirubin (i.e., bilirubin that is covalently bonded
to albumin) and, to a lesser extent, bilirubin that is physically
adsorbed to albumin substantially prolonged the survival of human
ventricular myocytes against in situ generated oxyradicals. This
cytoprotection, manifested at micromolar concentrations of either
form of bilirubin, surpasses those given by unconjugated bilirubin
alone, by equimolar levels of albumin (which has some cytoprotective
activity), by known antioxidants ascorbate, mannitol, or Trolox, and
by oxyradical scavenging enzymes superoxide dismutase (24,200 IU/L)
plus catalase (92,000 IU/L) on the same cells. Our human cell-based
data provide the first direct evidence that albumin-bound bilirubins,
especially delta bilirubin, are potent circulating cytoprotectors.
The latter may be important in defending, among others, the
myocardium, which is much less equipped in antioxidant defences than
for example the liver or intestines.
Institutional address:
Department of Clinical Biochemistry
University of Toronto
Ont.
Canada.
*****BIOCHEMICAL PHARMACOLOGY*****
(REFERENCE 4 OF 23)
96182782
Wu TW Fung KP Wu J Yang CC Weisel RD
Antioxidation of human low density lipoprotein by unconjugated and
conjugated bilirubins.
In: Biochem Pharmacol (1996 Mar 22) 51(6):859-62
We demonstrate here that both unconjugated bilirubin (Bu) and
conjugated bilirubin (Bc) can protect human low density
lipoprotein(LDL) against oxidation by oxyradicals generated by 2,2'-
azo-bis (2 amidinopropane) dihydrochloride at 37 degrees. The
oxidation was assessed by agarose gel electrophoresis and was further
corroborated by assaying the malondialdehydes and lipid peroxides
formed throughout oxidation. On a per mole basis, Bu and less so Bc
was more effective than ascorbate in preventing LDL oxidation. Since
oxidative modification of human LDL was implicated in plaque
formation in blood vessels leading to atherogenesis, the data
suggested that either bile pigment may help reduce the risk of
atherogenesis.
Institutional address:
Department of Clinical Biochemistry and Surgery
University of Toronto
Ontario
Canada.
*****BIOCHIMICA ET BIOPHYSICA ACTA*****
(REFERENCE 5 OF 23)
91159454
Kwak JY Takeshige K Cheung BS Minakami S
Bilirubin inhibits the activation of superoxide-producing NADPH
oxidase in a neutrophil cell-free system.
In: Biochim Biophys Acta (1991 Feb 15) 1076(3):369-73
We studied the effect of bilirubin on the NADPH-dependent superoxide
production induced by sodium dodecyl sulfate in a cell-free system
consisting of the membrane and cytosolic fractions of pig
neutrophils. Preincubation of the cytosolic fraction with bilirubin
before the addition of sodium dodecyl sulfate resulted in the time-
and dose-dependent inhibition of the superoxide production while the
preincubation of the membrane fraction with the tetrapyrrole did not
result in the inhibition. When the pigment was added after the
initiation of the reaction, the ongoing production was not affected
by the addition. Other tetrapyrroles, such as hemin, protoporphyrin
and biliverdin, also inhibited the production. The results indicate
that bilirubin inhibits the activation process of the superoxide
producing NADPH oxidase by decreasing the potency of the cytosolic
fraction and its inhibitory effect seems to be due to the hydrophobic
nature of the tetrapyrrole.
Institutional address:
Department of Biochemistry
Kyushu University School of Medicine
Fukuoka
Japan.
(REFERENCE 6 OF 23)
96085104
Hulea SA Wasowicz E Kummerow FA
Inhibition of metal-catalyzed oxidation of low-density lipoprotein by
free and albumin-bound bilirubin.
In: Biochim Biophys Acta (1995 Oct 26) 1259(1):29-38
Both free and albumin-bound bilirubin are known to scavenge peroxyl
radicals in vitro. In the present work we showed that free and
albumin-bound bilirubin at the physiological concentration of the
bile pigment in blood plasma could greatly inhibit the metal-
catalyzed oxidation of low density lipoprotein (LDL) as shown by the
reduced thiobarbituric acid reactivity, smaller or no shifts in
electrophoretic mobility, less apo B fragmentation and a decreased
amount of cholesterol oxidation products as detected by gas
chromatography. Free bilirubin (BR) was more effective in inhibiting
the production of thiobarbituric acid reactive substances in iron-
catalyzed LDL peroxidation as compared to the copper-catalyzed
reaction up to a BR to metal molar ratio of 4:1. Above this ratio the
same degree of inhibition was observed for both metal ions. It was
found that serum albumin provided full protection against Cu(2+)-
dependent oxidative stress only at very high protein to metal molar
ratio, i.e., 30:1, that is similar to that in human plasma.
Complexation of BR to albumin brought about a marked increase in the
capacity of the complex to bind metal ions, particularly iron, as
opposed to albumin alone. At a molar ratio of metal ion to albumin-BR
of 1:1 the inhibition of lipid peroxidation was about 96% and it was
almost complete at a molar ratio of 1:2. The ability of albumin-BR
complex to inhibit effectively the transition metals-dependent
oxidative stress could be important in the extravascular space where
local concentrations of metal ions may exceed the protein binding
capacity. In addition, the strong binding of iron to the albumin-BRcomplex
may be clinically important, especially in iron loaded sera
of hemochromatosis patients, where the transferrin is fully saturated
with this ion and the free iron could catalyze lipid peroxidation
unless bound by a metal trapping device such as the albumin-BR
complex.
Institutional address:
University of Illinois
Department of Food Science
Burnsides Research Laboratory
Urbana 61801
USA.
*****CELL BIOLOGY INTERNATIONAL REPORTS*****
(REFERENCE 7 OF 23)
93008294
Chen LX Lu JF Wang K
The influence of bilirubin on fluidity and rotational correlation
times of human erythrocyte membrane.
In: Cell Biol Int Rep (1992 Jun) 16(6):567-73
The effects of bilirubin on the membrane motion parameters of human
erythrocyte membrane were determined by the spin labelled ESR method.
It causes a decrease in the order parameter and an increase in the
corresponding fluidity of the lipid molecules. Bovine serum albumin
was found to inhibit effectively the effects due to bilirubin. The
disturbance to the organization of membrane molecules by bilirubin as
well as the protective effects of serum albumin are discussed on the
basis of the experimental results.
Institutional address:
National Laboratory of Natural and Biomimetic Drugs
Beijing Medical University
China.
*****EXPERIENTIA*****
(REFERENCE 8 OF 23)
90127285
Ribo JM Farrera JA Claret J
Proton-induced dismutation of superoxide in aprotic media by bile
pigments.
In: Experientia (1990 Jan 15) 46(1):63-7
Cyclic voltammetry of molecular oxygen in aprotic media
(dimethylformamide) and in the presence of bilirubin and other bile
pigments shows that superoxide anion (O2-.) undergoes proton-induced
dismutation. Lactam hydrogens of bile pigments are sufficiently acid
to induce (O2-.) disproportionation to O2 and H2O2. Because of its
characteristic lipophilic behavior, a biological role for natural
bilirubin similar to that of other non-enzymatic lipophilic
scavengers of (O2-.) is suggested.
Institutional address:
Departament de Quimica Organica
Universitat de Barcelona
Spain.
*****FEBS LETTERS*****
(REFERENCE 9 OF 23)
93387484
Neuzil J Stocker R
Bilirubin attenuates radical-mediated damage to serum albumin.
In: FEBS Lett (1993 Oct 4) 331(3):281-4
Oxidative damage to biological macromolecules has been implicated in
a number of diseases. Much interest has focused on how non-
proteinaceous, low-molecular weight antioxidants prevent oxidative
damage to lipids, while comparatively little is known about protein
antioxidation. Here we show that bilirubin (BR), the end-product of
heme catabolism, when bound to bovine serum albumin (BSA), is
oxidised by hydroxyl (.OH), hydroperoxyl (HO2.), and superoxide anion
(O2-.) radicals to so far mostly uncharacterised products. The
initial oxidation rates of BSA-bound BR decreased in the order OH >
HO2. > O2-.. BR protected its carrier protein from oxidative damage
inflicted by .OH radicals. This protective action included a
reduction in the .OH-mediated cleavage of BSA, conversion of Trp into
kynurenine and formation of 'bityrosine-specific' fluorescence. BR
also strongly inhibited .OH-mediated formation of protein carbonyls,
whereas ascorbate and Trolox (a water-soluble analogue of vitamin E)
were much less effective. These results support an antioxidant-
protective function of BR and point towards significant differences
in the efficacies of various antioxidants in the prevention of
oxidative damage to lipids and proteins.
Institutional address:
Biochemistry Group
Heart Research Institute
Sydney
NSW
*****FREE RADICAL BIOLOGY AND MEDICINE*****
(REFERENCE 10 OF 23)
93093494
Kazui M Andreoni KA Norris EJ Klein AS Burdick JF Beattie C
Sehnert SS Bell WR Bulkley GB Risby TH
Breath ethane: a specific indicator of free-radical-mediated lipid
peroxidation following reperfusion of the ischemic liver.
In: Free Radic Biol Med (1992 Nov) 13(5):509-15
A major component of the organ injury mediated by toxic oxidants,
such as seen following reperfusion of the ischemic liver, is due to
the peroxidation of polyunsaturated fatty acids, especially of cell
membranes. We utilized the measurement of exhaled breath ethane, a
metabolic product unique to oxidant-mediated lipid peroxidation, as a
noninvasive indicator of this process in swine liver subjected to
warm ischemia/reperfusion. Under rigorously controlled anesthesia
conditions, pig livers were subjected to 2 h of warm total ischemia,
followed by reperfusion in situ. Expired air was collected and its
ethane content quantitated by a novel gas chromatographic technique.
The time course of breath ethane generation correlated closely with
the appearance of hepatocellular injury as measured by impairment of
Factor VII generation and other measures of liver integrity.
Moreover, the administration of the specific superoxide free radical
scavenger, superoxide dismutase (SOD), significantly attenuated both
the elaboration of ethane and the hepatocellular injury. These
findings not only provide confirmation of the previously reported
link between hepatocellular injury by free radicals generated at
reperfusion, but also establish the use of expired breath ethane
analysis as a sensitive, specific, and noninvasive indicator of the
injury process in real time.
Institutional address:
Department of Surgery
Johns Hopkins Medical Institutions
Baltimore
MD 21287.
*****JOURNAL OF BIOLOGICAL CHEMISTRY*****
(REFERENCE 11 OF 23)
95197595
Bowry VW Mohr D Cleary J Stocker R
Prevention of tocopherol-mediated peroxidation in ubiquinol-10-free
human low density lipoprotein.
In: J Biol Chem (1995 Mar 17) 270(11):5756-63
Oxidation of low density lipoprotein (LDL) may be involved in the
development of atherosclerosis. It has recently been shown that alpha-
tocopherol (alpha-TOH) can act either as an antioxidant or prooxidant
for isolated low density lipoprotein (LDL). In the absence of an
effective co-antioxidant, alpha-TOH is a prooxidant and this activity
is evidently due to reaction of the alpha-tocopheroxyl radical (alpha-
TO.) with the LDL's polyunsaturated lipids (Bowry, V. B., and
Stocker, R. (1993) J. Am. Chem. Soc. 115, 6029-6045). Herein we
examined the effectiveness of selected natural and synthetic radical
scavengers as co-antioxidants for inhibiting peroxyl radical-induced
peroxidation in LDL that is devoid of ubiquinol-10 (an effective
endogenous co-antioxidant) but still contains most of its natural
complement of alpha-TOH. Various quinols, catechols, and
aminophenols, as well as ascorbate, 6-palmityl ascorbate, and
bilirubin, were very effective co-antioxidants under our test
conditions, whereas ordinary phenolic antioxidants, including short-
tailed alpha-TOH homologues, were less effective. Reduced
glutathione, urate, and Probucol were ineffective. These findings
confirm that the prooxidant activity of alpha-TOH in LDL relies
heavily on the segregation of water-insoluble radicals (particularly
alpha-TO.) into individual LDL particles, since it was those
compounds that are expected to either irreversibly reduce alpha-TO. or
accelerate the diffusion of radicals between particles which most
effectively inhibited the tocopherol-mediated phase of peroxidation.
Theoretical and practical implications of these findings are
discussed, as is their relevance to the "LDL oxidation" hypothesis of
atherogenesis.
Institutional address:
Biochemistry Group
Heart Research Institute
Sydney
New South Wales
Australia.
(REFERENCE 12 OF 23)
94266886
Neuzil J Stocker R
Free and albumin-bound bilirubin are efficient co-antioxidants for
alpha-tocopherol, inhibiting plasma and low density lipoprotein lipid
peroxidation.
In: J Biol Chem (1994 Jun 17) 269(24):16712-9
Peroxidation of the lipid moieties of low density lipoproteins (LDL)
is regarded as an early event in atherogenesis. Because bilirubin is
a physiological reductant with antioxidant activities, we
investigated its inhibitory action on the radical-mediated oxidation
of LDL and plasma lipids. Exposing fresh human blood plasma to
lipophilic peroxyl radicals generated from 2,2'-azobis(2,4-
dimethylvaleronitrile) (AMVN) resulted in rapid oxidation of
ubiquinol-10, followed by that of ascorbate and bilirubin. Plasma
lipids were well protected from peroxidation as long as these three
antioxidants were present, as assessed by the amounts of
cholesterylester hydroperoxides formed during this period. Following
consumption of these antioxidants, and in the presence of alpha-
tocopherol, the rate of hydroperoxide formation increased sharply
with roughly 2 molecules of cholesterylester hydroperoxides being
formed for each peroxidation initiating event. Supplementation of
AMVN-oxidizing plasma with exogenous bilirubin at the onset of rapid
lipid peroxidation, i.e. after depletion of endogenous ubiquinol-10,
ascorbate, and bilirubin, led to a halt in both hydroperoxide
formation and consumption of alpha-tocopherol. When isolated LDL was
incubated with AMVN, approximately 9 molecules of cholesterylester
hydroperoxides were formed per peroxidation initiating event and
while alpha-tocopherol was consumed. Addition of free or albumin-
bound bilirubin to isolated LDL at the onset of oxidation resulted in
a strong inhibition of hydroperoxide formation and alpha-tocopherol
consumption, the effect being more pronounced with the free pigment.
Addition of the corresponding amounts of albumin alone was without
effect. In the presence of albumin-bound bilirubin, some 30% of the
pigment was initially converted into biliverdin, whereas formation of
this oxidation product was not observed with the free pigment. Also,
the presence of bilirubin oxidase partially reversed the inhibitory
activity of bilirubin on AMVN-induced LDL oxidation in the absence
but not presence of albumin. An attenuation of hydroperoxide
formation and a temporary increase in LDL's alpha-tocopherol
concentration were observed when free- or albumin-bound bilirubin
were added to AMVN-oxidizing, alpha-tocopherol-containing LDL. In
contrast, hydroperoxide formation was not inhibited significantly
when the albumin-bound pigment was added to oxidizing LDL after
complete consumption of its alpha-tocopherol. Our results show that
bilirubin inhibits oxidation of LDL lipids initiated within the
lipoprotein core and indicate that this activity is mediated by
interaction of the pigment with LDL's alpha-tocopherol.
Institutional address:
Biochemistry Group
Heart Research Institute
Sydney
New South Wales
Australia.
*****LANCET*****
(REFERENCE 13 OF 23)
91287428
Benaron DA Bowen FW
Variation of initial serum bilirubin rise in newborn infants with
type of illness [see comments]
In: Lancet (1991 Jul 13) 338(8759):78-81
Hyperbilirubinaemia in newborn infants is generally regarded as a
problem, and bilirubin itself as toxic metabolic waste, but the high
frequency in newborn infants suggests that the excess of neonatal
bilirubin may have a positive function. To investigate the hypothesis
that bilirubin has a role as a free-radical scavenger, the rate of
rise in serum bilirubin in the first few days of life was measured in
44 infants with five illnesses thought to enhance free-radical
production and in 58 control infants. The infants were selected from
2700 consecutive births by exclusion of those with factors known to
affect bilirubin metabolism, including enteral feeding. The control
infants were those who seemed to be ill and received treatment,
including restriction of enteral feeds, but in whom no illness, or
disorders not related to free-radical production, were found. The
mean serum bilirubin rise was significantly lower in the combined
illness group than in the control group (36.1 [95% Cl 26.9-45.3] vs
66.7 [55.9-77.5] mumol.l-1.day-1; p less than 0.0001). In subgroup
analyses the mean rises in infants with circulatory failure, neonatal
depression/asphyxia, aspiration syndromes, and proven sepsis were
significantly lower than in controls matched for gestational age and
birthweight, but rises in infants with respiratory distress and their
matched controls did not differ. These findings are consistent with
the hypothesis that bilirubin is consumed in vivo as an antioxidant. Such
consumption may operate in vivo in addition to the standard
pathways for bilirubin metabolism (productio isomerisation, and
excretion).
Lancet (1991 Jul 13) 338(8759):78-81
*********************************************
Institutional address:
Section on Newborn Pediatrics
Pennsylvania Hospital
Philadelphia.
*****METHODS IN ENZYMOLOGY*****
(REFERENCE 14 OF 23)
91041806
Stocker R McDonagh AF Glazer AN Ames BN
Antioxidant activities of bile pigments: biliverdin and bilirubin.
In: Methods Enzymol (1990) 186:301-9
[No Abstract Available]
*****PROCEEDINGS OF THE SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE*****
(REFERENCE 15 OF 23)
92253589
Krinsky NI
Mechanism of action of biological antioxidants.
In: Proc Soc Exp Biol Med (1992 Jun) 200(2):248-54
More and more diseases have been proposed to have a radical or
oxidant involvement. Although in most cases we do not know if this
involvement is a cause or a result of the disease process, it is
still valuable to learn about those compounds or enzymes that might
block, inhibit, or prevent radical-initiated reactions. Therefore, it
becomes increasingly important to understand which compounds can
function as antioxidants, where they are located in the body, and
what their mechanism of action might be. As we increase our knowledge
in these areas, we will have a better opportunity to propose
interventions that might suppress or even reverse some of the ravages
of oxidant-based diseases in humans.
Institutional address:
Department of Biochemistry
Tufts University School of Medicine
Boston
Massachusetts 02111-1837.
*** <NOT IN University of Colorado Boulder> ***
*****ACTA PAEDIATRICA*****
(REFERENCE 16 OF 23)
95037113
Varsila E Hallman M Andersson S
Free-radical-induced lipid peroxidation during the early neonatal
period.
In: Acta Paediatr (1994 Jul) 83(7):692-5
The effect of gestational age on postnatal free-radical-mediated
lipid peroxidation was studied in 19 term (gestational age 37-42
weeks) and 21 healthy preterm (gestational age 31-36 weeks) infants
by measurement of expired ethane and pentane during the first 7 days
of life. Ethane (11.9 versus 5.7 pmol/kg/min; p = 0.0001) and pentane
(11.4 versus 7.5 pmol/kg/min; p = 0.01) were significantly higher in
preterm than in term infants. Correlations were found between
gestational age and ethane (r = 0.60, p = 0.0001) for days 1-7 and
pentane (r = 0.54, p = 0.0003) for days 3-7; and between birth weight
and ethane (r = 0.58, p = 0.0001) and pentane (r = 0.55, p = 0.0003).
These results indicate that during the postnatal period, immaturity
is a major factor determining the rate of free-radial-mediated lipid
peroxidation.
Institutional address:
Children's Hospital
University of Helsinki
Finland.
*****CLINICS IN PERINATOLOGY*****
(REFERENCE 17 OF 23)
90315758
McDonagh AF
Is bilirubin good for you?
In: Clin Perinatol (1990 Jun) 17(2):359-69
Bilirubin is generally considered to be a diagnostically useful,
sometimes toxic, metabolic waste product--and nothing more. Many
studies, however, summarized in this article, have shown that
bilirubin is an effective lipid-soluble antioxidant in vitro, even at
physiologic concentrations, vying with even vitamin E in its ability
to intercept and inhibit free radical chain reactions that generate
hazardous lipid peroxides. These studies suggest that bilirubin may
have a biochemical function in vivo and belong to a group of low-
molecular weight antioxidants that together provide protection from
cellular damage by endogenous-organic free radicals. Dovetailing with
the notion that bilirubin may have a protective function is the
recent discovery that heme oxygenase, one of the enzymes responsible
for bilirubin formation, is a heat-shock protein, one of a group of
proteins that are thought to protect organisms from oxidative and
other forms of biochemical stress. Thus, the biochemical path from
red to green to yellow may defend as well as degrade, and modest
levels of the end product may possibly be physiologically beneficial.
Institutional address:
Department of Medicine
University of California
San Francisco.
*****FORTSCHRITTE DER MEDIZIN*****
(REFERENCE 18 OF 23)
94292066
Bervoets K Schlenzig JS Bohles H
[Bilirubin in the early neonatal period. Is there a positive aspect
of hyperbilirubinemia?--A medical hypothesis]
Bilirubin in der fruhen Neugeborenenperiode. Gibt es positive Aspekte
einer Hyperbilirubinamie?--Eine medizinische Hypothese.
In: Fortschr Med (1994 May 10) 112(13):192-4 (Published in German)
The fact that almost all neonates exhibit a "physiological" jaundice,
prompts the question whether bilirubin, usually exclusively
considered a potentially toxic endproduct of the metabolism of heme,
might not also have a positive task in the first days of life. A
recently discovered property of bilirubin under in vitro conditions
is its ability to combine with free oxygen radicals such as are
produced in the oxidative metabolic processes of the neonate
immediately following birth. In the present article, the concept of
the anti-oxidative effect of bilirubin, and its translation to the
early neonatal period is presented and discussed on the basis of a
number of examples.
Institutional address:
Zentrum der Kinderheilkunde
Allgemeine Padiatrie I
Universitat Frankfurt/M.
*****FREE RADICAL RESEARCH COMMUNICATIONS*****
(REFERENCE 19 OF 23)
89253034
Stocker R Peterhans E
Antioxidant properties of conjugated bilirubin and biliverdin:
biologically relevant scavenging of hypochlorous acid.
In: Free Radic Res Commun (1989) 6(1):57-66
Conjugated bilirubin at low micromolar concentrations strongly
inhibits the luminol-enhanced chemiluminescence response of
stimulated human polymorphonuclear leukocytes. In contrast, it does
not inhibit either reduction of ferricytochrome c or lucigenin-
mediated chemiluminescence of stimulated cells. Also, conjugated
bilirubin and its metabolic precursor, biliverdin, do not inhibit the
enzyme myeloperoxidase (MPO) since (i) the MPO-dependent oxidation of
guaiacol is not affected by biliverdin and (ii) the spectral changes
observed when conjugated bilirubin is oxidized by a MPO-H2O2-Cl(-)-
system are very similar to those obtained with reagent HOCl. As
judged from these spectroscopic studies, each molecule of conjugated
bilirubin can scavenge one molecule of HOCl giving rise to an
oxidation product that itself is capable of scavenging further
molecules of HOCl. Importantly, at physiological pH, both bile
pigments can efficiently protect the elastase-inhibitory capacity of
alpha 1-antiprotease against inactivation by reagent HOCl.
Institutional address:
Institute of Veterinary Virology
University of Berne
Switzerland.
*****ITALIAN JOURNAL OF GASTROENTEROLOGY*****
(REFERENCE 20 OF 23)
92199250
Lang I Nekam K Deak G Muzes G Gonzales-Cabello R Gergely P
Csomos G Feher J
Immunomodulatory and hepatoprotective effects of in vivo treatment
with free radical scavengers.
In: Ital J Gastroenterol (1990 Oct) 22(5):283-7
The hepatoprotective and immunomodulatory effects of silymarin and
amino-imidazol-carboxamid-phosphate were studied in 60 patients with
compensated alcoholic cirrhosis of the liver in a one month double
blind clinical trial. Treatment with both drugs normalized the
elevated levels of aspartate aminotransferase, alanine
aminotransferase and serum bilirubin, markedly reduced the high level
of gamma-glutamyl transferase, increased lectin-induced
lymphoblasttransformation, decreased the percentage of CD8+ cells and
suppressed lymphocytotoxicity. None of these changes occurred in the
placebo-treated group. Thus the hepato-protective effects of
silymarin and amino-imidazol-carboxamid-phosphate are accompanied by
changes in parameters of cellular immunoreactivity of the treated
patients.
Institutional address:
Second Department of Medicine
Semmelweis University Medical School
Budapest
Hungary.
*****JOURNAL OF PERINATOLOGY*****
(REFERENCE 21 OF 23)
95054551
Hegyi T Goldie E Hiatt M
The protective role of bilirubin in oxygen-radical diseases of the
preterm infant.
In: J Perinatol (1994 Jul-Aug) 14(4):296-300
We hypothesized that because bilirubin is a potent free-radical
quencher, infants without disorders that have oxygen-radical disease
(ORD)-mediated mechanisms may have higher bilirubin levels than
infants suffering from conditions possibly associated with ORD-
mediated mechanisms (e.g., necrotizing enterocolitis, broncopulmonary
dysplasia, intraventricular hemorrhage, and retinopathy of
prematurity). We identified 25 infants (birth weight 912 +/- 208 gm,
gestational age 27 +/- 3 weeks) who comprised the ORD group and
compared them with 57 controls (birth weight 1242 +/- 248 gm,
gestational age 31 +/- 3 weeks). Infants with ORD had lower peak
serum bilirubin concentrations, later ages at peak, and lower
incidence of peak bilirubin concentrations exceeding 10 or 15 mg/dl.
In addition, these infants exhibited a slower rate of bilirubin rise
and a smaller area under the bilirubin-time curve measure compared
with controls. To control for different birth weights, we analyzed
subgroups weighing < 1000 gm. Significant differences were again
identified in peak bilirubin concentrations, age at peak,
phototherapy duration, and area under the curve. In this population
of preterm infants, higher bilirubin levels were associated with a
lower incidence of oxygen radical-mediated injury.
Institutional address:
Department of Pediatrics
UMDNJ-Robert Wood Johnson Medical School
St. Peter's Medical Center
New Brunswick 08903.
*****SEIKAGAKU. JOURNAL OF JAPANESE BIOCHEMICAL SOCIETY*****
(REFERENCE 22 OF 23)
95279840
Yamaguchi T
[Bilirubin production and its physiological significance]
In: Seikagaku (1995 Feb) 67(2):148-51 (Published in Japanese)
[No Abstract Available]
Institutional address:
Department of Biochemical Genetics
Tokyo Medical and Dental University.
*****TANPAKUSHITSU KAKUSAN KOSO. PROTEIN, NUCLEIC ACID, ENZYME*****
(REFERENCE 23 OF 23)
89283236
Onishi S Itoh S Isobe K Ochi M Kondoh M
[Pathophysiological significance of bilirubin in neonatal jaundice as
a defence mechanism against active oxygen during perinatal period]
In: Tanpakushitsu Kakusan Koso (1988 Dec) 33(16):3005-16
(Published in Japanese)
[No Abstract Available]
Kate
At 07:01 AM 5/19/96 GMT, midasgold wrote:
>>some level of jaundice is desireable due to the free radical
>>scavenging effect of bilirubin
>
>Kate -
>
>I would be very interested in the studies on this to which you referred.
>My second baby (born in '83) had jaundice, which I now believe was
>prolonged due to my following the doctor's recommendation to give him H20
>(instead of colostrum). I was furthermore told that this was "breastmilk
>jaundice" - even though it occurred shortly after his birth - and I should
>stop BFing for 24-48 hours...this advice I did not follow. In addition to
>the aforementioned studies, what is the latest information that you and/or
>anyone else on Lactnet have to share on "breastmilk jaundice?"
>
>Deanna Goldberg, BS, AAHCC
>Certified Childbirth Educator
>Labor-Support Doula
>West Hempstead, NY
>
>
Kate
In the United States, breastfeeding legislation has been enacted in ten
states over the past two years, and many more states have pending bills. The
legislation typically clarifies the fact that breastfeeding is not indecent
exposure, and thus not criminal behavior. Most of the states have gone
further than this, making it perfectly clear that a woman has a right to
breastfeed any place she has the right to be. --
http://www.prairienet.org/llli/LawBills.html
http://www.cs.colorado.edu/~kolina/Home.html (my home page)
http://www.cs.colorado.edu/~grunwald/House.html Buy our House!
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