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At least 19 recordsLinked to original sources

PubMed1989

Effects of sodium bromate on ionic concentrations and osmolalities of the cochlear fluids in guinea pigs.

Effects of sodium bromate on cochlear potentials and electrolyte composition of the cochlear fluids in guinea pigs were investigated following administration of sodium bromate into the cochlea, using perilymphatic perfusion. Cochlear microphonics and the whole nerve action potential of the auditory nerve were markedly suppressed. The K+ and Cl- activities in the endolymph as well as the endocochlear dc potential (EP) decreased significantly and irreversibly, in proportion to the concentration of sodium bromate. A negative EP never developed during the monitoring of 120 min. Microsamples of the endolymph showed substantial decreases of K+ and Cl- concentrations and an increase in the concentration of Na+. Osmolality of the endolymph was much lower than that of the perilymph. The severe edema of the stria vascularis and collapse of Reissner's membrane were histologically evident. These events suggest a breakdown of the endolymph-perilymph barrier, coincident with an inhibition of the strial active transport, as a result of the ototoxic action of sodium bromate. The possible ion and water movement across the endolymph-perilymph barrier in the presence of sodium bromate is discussed.

Acoustic Stimulation↗

PubMed1976

[Peripheral nerve disease associated with acute renal failure due to bromate poisoning].

A case of 21 year old male with neuropathy caused by renal insufficiency was present. He had taken bromate (mixed powder of potassium bromate and sodium bromate) for the purpose of suicide and suffered from acute renal insufficiency and hard of hearing. Renal dysfunction improved gradually by peritoneal dialysis and hemodialysis. However, on the 32th day after the onset, burning pain appeared in the bilateral feets. Following this, he began to complain of the disturbances of superficial and deep sensory below the ankle jerks and the weakness of his toes. Considering the clinical features, we supposed that the disturbance of the peripheral nerve was caused by uremia due to taking bromate. N. suralis was biopsied on the 80th day after the onset and examined electron microscopically. Electroscopical findings was as follows. Degeneration of the Schwann cells and irregularity or destruction of the myelin sheaths were observed. The axoplasm of the myelinated nerve fiber were relatively preserved as compared with the changes of the myelin sheaths. In the unmyelinated nerve fibers, cavity formations were observed. The findings of regeneration were not observed. From the electron microscopical findings, we speculate that the changes of the Schwann cells and the myelin sheaths are primary resulting from the disturbance of the metabolism of the Schwann cells. We speculate that anemia and hypoproteinemia caused by bromate disturbed regeneration.

Acute Kidney Injury↗

PubMed1991

Structure of hexaaquanickel(II) bromate.

[Ni(H2O)6](BrO3)2, Mr = 422.60, cubic, Pa3, a = 10.2987 (6) A, V = 1092.3 (2) A3, Z = 4, F(000) = 824, Dx = 2.57 g cm-3, lambda(Mo K alpha) = 0.71073 A, mu = 90.79 cm-1, T = 296 K, R = 0.024 for 360 unique reflections having I greater than sigma I. The single type of nickel ion is coordinated by six water-molecule O atoms, each at an observed distance of 2.061 (2) A, in an almost regular octahedral array. The single type of bromate ion has an observed Br--O bond length of 1.655 (2) A and O--Br--O bond angle 104.25 (9) degrees. Both the nickel-oxygen complex and the bromate ion were found to manifest rigid-body behavior. The Ni--O distance corrected for rigid-body motion is 2.065 A, while the corrected Br--O bond length is 1.663 A. Location and refinement of the two inequivalent H atoms permitted a detailed analysis of the hydrogen bonding, which occurs principally between the oxygen octahedron and the bromate groups. This structure is isomorphic to the structures of hexaaquanickel(II) chlorate and hexaaquacobalt(II) bromate which have been reported recently from this laboratory.

Bromates↗

PubMed1991

Structure of hexaaquacopper(II) bromate.

[Cu(H2O)6](BrO3)2, Mr = 427.44, cubic, Pa3, a = 10.3240 (6) A, V = 1100.38 (4) A3, Z = 4, Dx = 2.580 g cm-3, lambda (Mo K alpha) = 0.71073 A, mu = 92.32 cm-1, F(000) = 828, T = 296 K, R = 0.038 for 336 unique reflections having I greater than sigma I. The single type of copper ion (site symmetry 3) is coordinated by six water-molecule O atoms, each at an observed distance of 2.079 (4) A, in an array which is virtually regular octahedral, the nominal 90 degree angles measuring 89.95 (15) and 90.05 (15) degrees. Thus, this is not a typical CuII complex in which (consistent with a static Jahn-Teller effect) a distorted octahedral array displays '(2 + 2 + 2)' coordination; rather, it is the sixth strict example of a CuII static structure inconsistent with the Jahn-Teller theorem. The presence of a dynamic Jahn-Teller effect is supported by the data. The single type of bromate ion has an observed Br-O bond length 1.649 (3) A and O-Br-O bond angle 104.17 (15) degrees. The bromate ion was found to manifest rigid-body behavior but, consistent with a dynamic Jahn-Teller effect, the copper-oxygen complex did not. The Br-O bond length corrected for rigid-body motion is 1.663 A. Refinement of the positional parameters of the two inequivalent H atoms permitted a detailed analysis of hydrogen bonding, which occurs principally between the oxygen octahedra and the bromate groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Bromates↗

PubMed1992

The structure of hexaaquaaluminium(III) bromate trihydrate, [Al(H2O)6](BrO3)3.3H2O.

Hexaaquaaluminium(III) bromate trihydrate, [Al(H2O)6](BrO3)3.3H2O, M(r) = 572.84, triclinic, P1, a = 9.536 (2), b = 11.095 (4), c = 9.291 (2) A, alpha = 106.58 (2), beta = 100.42 (2), gamma = 113.01 (2) degrees, V = 818.1 (4) A3, Z = 2, Dx = 2.33 g cm-3, lambda(Mo K alpha) = 0.71073 A, mu = 74.58 cm-1, F(000) = 560, T = 296 K, R = 0.050 for 3777 unique reflections having I greater than sigma 1. The single type of Al ion is coordinated by six inequivalent water O atoms which form a slightly distorted octahedron. The average Al--O distance within the octahedron is 1.872 (11) A. Each of the three inequivalent bromate groups has three inequivalent O atoms. The average Br--O distances and O--Br--O angles for these ions are: 1.652 (25) A and 104.1 (17) degrees for Br(1)O3; 1.650 (9) A and 104.4 (18) degrees for Br(2)O3; 1.643 (9) A and 103.6 (14) degrees for Br(3)O3. The aluminium-oxygen complex conformed to rigid-body behavior but the bromate groups did not. Corrected for rigid-body motion, the average Al--O distance becomes 1.880 (10) A. Least-squares refinement of the positional parameters of the 18 inequivalent H atoms permitted a detailed analysis of the hydrogen bonding.

Aluminum↗

PubMed1992

Polarized dispersion, glide-rule-forbidden reflections and phase determination in barium bromate monohydrate.

Reflections forbidden by a glide-plane rule are observed in diffraction experiments with a crystal of barium bromate monohydrate using linearly polarized synchrotron radiation with wavelength near the bromine K-absorption edge. Their intensities change with azimuth in agreement with equations derived using a tensor model of the anomalous scattering of the bromate ion and are consistent in scale with earlier measurements of that tensor in sodium bromate. The intensity of each forbidden h0l reflection gives the magnitude and phase of the bromine part of the structure factor of the allowed 2h,0,2l reflection. The x and z coordinates of the Br atom determined from such data for 11 reflections are within 0.02 A of those from two crystal structure determinations.

Barium↗

PubMed1990

Structure of hexaaquacobalt(II) bromate.

[Co(H2O)6](BrO3)2, Mr = 422.83, cubic, Pa-3, a = 10.3505 (7) A, V = 1108.88 (8) A3, Z = 4, Dx = 2.53 g cm-3, lambda(Mo K-alpha) = 0.71069 A, mu = 87.31 cm-1, F(000) = 820, T = 296 K, R = 0.027 for 365 unique reflections having I greater than sigma I. The single type of Co ion is coordinated by six water-molecule O atoms, each at an observed distance 2.095 (2) A, in an array which is regular octahedral within the estimated standard deviations of the relevant angles. The single type of bromate ion has a Br-O bond length 1.653 (2) A and O-Br-O bond angle 104.07 (9) degrees. The cobalt-oxygen complex manifested rigid-body behavior, but the bromate ion did not. The cobalt-oxygen distance corrected for rigid-body motion is 2.099 A. Location and refinement of the two inequivalent H atoms permitted detailed analysis of the hydrogen bonding, which occurs principally between the oxygen octahedra and the bromate groups. This structure is isomorphic to that of hexa-aquanickel(II) chlorate recently reported from this laboratory.

Bromates↗

PubMed1991

Substitute anions and the chloride conductance of frog muscle: effects of chlorate and bromate on steady-state values and kinetics.

Voltage-clamp experiments have been used to study the effects of external nitrate, chlorate and bromate on the chloride conductance of sarcolemma of Xenopus laevis. Nitrate reduces inward current (chloride efflux), but less potently than does thiocyanate [Vaughan (1987) Pflügers Arch 410:153-158] and does not affect conductance kinetics. As its concentration is increased the blocking effect of nitrate saturates; at a nitrate mole fraction of 0.6 the anion conductance is reduced to about 50% and further increases in nitrate concentration are without significant effect. Nitrate's influences are not voltage-dependent. Chlorate is a much less potent blocker than is nitrate, and its effects are voltage-dependent. With small hyperpolarizations, currents are sometimes seen to be larger than the control, but the degree of block (or the conversion of augmentation to reduction) increases with the size of the voltage step. Anomalous mole-fraction effects are observed in the range 0.4-0.6 mol/mol, in that in some cells the reduction of conductance is noticeably greater in the lower than in the higher concentration of the replacement ion. In the presence of chlorate, relaxation rates are significantly increased, and this influence is not anomalously dependent on the mole fraction. Similar effects are observed in bromate. The effect on kinetics is not pH-dependent. The main series of experiments was conducted at pH 5, but the same influence on kinetics was observed at pH 9. Using point voltage-clamp experiments, chlorate and thiocyanate were both seen to lower the contraction threshold voltage, but thiocyanate has no influence on conductance kinetics.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

Effect of route of administration in the micronucleus test with potassium bromate.

The effect of intraperitoneal injection (i.p.) versus oral gavage administration (p.o.) of potassium bromate was examined using the micronucleus test in 2 strains of male mice (MS/Ae and CD-1). First, a small acute toxicity test and a pilot micronucleus experiment were performed to determine the appropriate dose range and sampling time for the full-scale micronucleus test. The full-scale test was carried out using doses of 18.8, 37.5, 75, and 150 mg/kg in the i.p. test and of 37.5, 75, 150, and 300 mg/kg in the p.o. test. The sampling time was 24 h for both mouse strains. Potassium bromate induced micronucleated polychromatic erythrocytes (MNPCEs) dose-dependently by both routes of administration in both mouse strains. No distinct difference in route of administration was observed in the test with MS/Ae mice. In CD-1 mice more MNPCEs were induced by the i.p. route than by the p.o. route.

Administration, Oral↗

PubMed1990

Bromate intoxication: hairdressers' anuria.

A 17-year-old hairdresser developed sodium bromate poisoning after drinking a cup of hair neutralizer in a suicide attempt. She presented 1 week later with anuria, required hemodialysis for 5 days, and subsequently recovered. Sensorineural hearing loss, often a characteristic finding, was absent. Early diagnosis of bromate intoxication requires an appreciation that it commonly occurs in hairdressers, may be accompanied by deafness, and may present with insidious anuria.

Adolescent↗

PubMed1992

Two children with bromate intoxication due to ingestion of the second preparation for permanent hair waving.

We report two children who suffered from sodium bromate intoxication due to ingestion of the second preparation for permanent hair waving (the second permanent preparation). One child suffered from gastrointestinal symptoms only. The other exhibited slight acute renal insufficiency. Results of the histological examination of the kidney in the sick child with acute renal insufficiency showed sporadic epithelial separation of the proximal tubuli under light microscopy. In addition, we could demonstrate more clearly epithelial separation and unbroken tubular basement membranes under electron microscopy (EM). To our knowledge, this is the first report of EM findings in this disease. The mechanism of epithelial injuries by bromate is not clear.

Acute Kidney Injury↗

PubMed1988

The effects of cetrimide and potassium bromate on the potassium ion concentration in the inner ear fluid of the guinea-pig.

The mammalian inner ear is located deep within the temporal bone. The organ of Corti, the delicate sensory system for sound, is surrounded by two fluid systems; the potassium-rich endolymph and the sodium-rich perilymph. The pathogenesis of inner ear deafness is thought to be largely due to an imbalance of potassium and sodium ions in the inner ear fluids. Dynamic changes in K+ in the endolymph and perilymph were studied in the guinea-pig following cetrimide (cetrimonium bromide, a powerful cationic detergent which shows ototoxicity) applications on the round window membrane, intramuscular injection of potassium bromate (bread whitener, known to cause renal damage and permanent deafness in animals and man). Maximum fall in K+ concentration in the endolymoh (mM/min) and maximum K+ conductance (mM/min/mV) were 3.54 +/- 1.65 and 0.036 +/- 0.02 in cetrimide, and 1.85 +/- 0.35 and 0.021 +/- 0.009 in potassium bromate, respectively. In view of these findings, the influence of the active transport mechanism to K+ concentrations are discussed in comparison with dynamic changes in endolymph K+ induced by asphyxia and ethacrynic acid.

Animals↗

PubMed1975

Deafness and renal failure due to potassium bromate poisoning.

Several substances are known to have a profound effect on both the kidney and the inner ear. The aminoglycoside antibiotics are toxic to both of these organs. Ethacrinic acid and furosemide affect transport mechanisms in the loop of Henle as well as the inner ear. In addition, studies have suggested antigenic similarities between the stria vascularis of the cochlea and the renal tubules. This report of potassium bromate poisoning and its resultant deafness and renal failure further emphasizes the curious relationship between these two organ systems.

Acute Kidney Injury↗

PubMed1992

Effects of antioxidants on induction of micronuclei in rat peripheral blood reticulocytes by potassium bromate.

Micronucleus induction in male F344 rat peripheral blood by potassium bromate (KBrO3), a rat renal carcinogen, and its inhibition by several antioxidants were studied using the acridine orange supravital staining method. The frequency of micronucleated reticulocytes (MNRETs) peaked 32 h after a single i.p. treatment of rats with KBrO3 at a dose of 60 mg/kg. Co-treatment with glutathione (GSH) or cysteine (Cys) i.p. at doses of 800 mg/kg and 400 mg/kg, respectively, 30 min before and 30 min after the KBrO3 treatment significantly inhibited the micronucleus induction by KBrO3. Daily i.g. administration of vitamin C for 5 days at a dose of 200 mg/kg/day was also effective in protecting against micronucleus induction by KBrO3 given on the 4th day. However, co-treatment with superoxide dismutase in liposome-encapsulated form by i.p. injection at a dose of 18,000 U/kg 30 min before and 30 min after the KBrO3 application exerted no effect. The results indicate that antioxidants, especially sulfhydryl compounds, have protective potential against the clastogenicity of KBrO3, also suggesting that active oxygen species may play an important role in its clastogenicity.

Acridine Orange↗

PubMed1988

Acute cytogenetic effects of potassium bromate on rat bone marrow cells in vivo.

The acute cytogenetic effects of potassium bromate (KBrO3) on rat bone marrow cells in vivo were studied. The incidence of chromosome aberrations in bone marrow cells increased rapidly, reaching a maximum level 12 h after intraperitoneal injection and decreased within 24 h. Dose-response relationships were obtained for both intraperitoneal and oral administrations.

Administration, Oral↗

PubMedDate not supplied

Induction of micronucleated reticulocytes by potassium bromate and potassium chromate in CD-1 male mice.

Micronucleus tests of potassium bromate (KBrO3) and potassium chromate (K2CrO4) were conducted with peripheral blood reticulocytes (PB-RETs) of CD-1 male mice dose intraperitoneally. Peripheral blood cells collected from the tail were stained supravitally with acridine orange (AO) using AO-coated glass slides. Both KBrO3 and K2CrO4 induced micronuclei in PB-RETs in the same manner as in polychromatic erythrocytes of bone marrow.

Animals↗

PubMed1992

Lack of renal tumour-initiating activity of a single dose of potassium bromate, a genotoxic renal carcinogen in male F344/NCr rats.

The renal tumour-initiating activity of potassium bromate (KBrO3), a known genotoxic rat renal carcinogen, was investigated in male F344/NCr rats. 6-wk-old rats were given KBrO3 intragastrically as a single dose of 300 mg/kg body weight, which was confirmed by our preliminary toxicity study as a maximum tolerated single dose for this strain of rat. Starting 2 wk after KBrO3 treatment, groups of 39 rats received either a basal diet or a diet containing 4000 ppm barbital sodium (BBNa) as a promoting regimen and were killed at 30, 52, or 104 wk. Control rats received either dietary BBNa (4000 ppm) or the basal diet alone from wk 2 to 52 or 104 wk. Nephropathy was observed in all rats treated with KBrO3 followed by BBNa at 30 wk and in rats receiving BBNa alone, but not in rats exposed to KBrO3 alone. Dysplastic renal tubular cell foci (DTF), putative preneoplastic renal tubular cell lesions were found associated with nephropathy in rats exposed to KBrO3 followed by BBNa from 47 wk. The incidences and multiplicities of DTF and renal tubular cell tumours observed from 31 to 104 wk revealed no initiating effect of KBrO3 treatment. These results indicate that the KBrO3 dose of 300 mg/kg did not initiate renal carcinogenesis.

Animals↗

PubMed1992

Generation of active oxygen species in vitro by the interaction of potassium bromate with rat kidney cell.

Active oxygen species derived from the interaction of potassium bromate (KBrO3), a rat renal carcinogen, with cells from rat kidney and other organs were examined by electron spin resonance spectrometry using the spin trapping agents 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and 2,2,6,6-tetramethylpiperidine (TEMP). DMPO-OH, an indicator of hydroxyl radical production, was generated from KBrO3 by kidney cells or homogenate, but not by liver preparations and to only a limited extent by heart and brain homogenates, suggesting relative kidney specificity. To assess what chemical components are responsible for production of DMPO-OH, several physiologically related materials were examined. Glucose, saccharose, albumin and methyl linolate were found not to be involved in the KBrO3 reaction, but reduced glutathione and also ferric ions participated to produce DMPO-OH. In addition, DMPO-OH production derived from the reaction of KBrO3 with kidney homogenate was not affected by superoxide dismutase, catalase or hydroxyl radical scavengers such as DMSO or ethanol, but was effectively inhibited by singlet oxygen scavengers such as histidine and NaN3, implying singlet oxygen production. To assess this possibility, TEMP was used as a trapping agent, and TEMPO, derived from singlet oxygen, was found to be produced by the reaction of KBrO3 with homogenates of kidney, but not of liver. Furthermore, singlet oxygen production was confirmed by studies of chemiluminescence using 2-methyl-6-phenyl-3,7-dihydroimidazo[1,2a]pyrazine-3-one. As a control, DMPO-OH was also demonstrated to be produced by a known singlet oxygen source, toluidine blue plus light. The results thus indicate that singlet oxygen is a very probably candidate for the active oxygen species generated in the specific interaction of KBrO3 with rat kidney cells in vitro. This raises the question of its concern with renal carcinogenicity in vivo.

Animals↗