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PubMed1981

Neurotoxicity of acrylamide and related compounds and their effects on male gonads in mice.

Neurotoxicity of acrylamide and related compounds and their effects on the testis after repeated oral doses were studied in mice. Of fourteen analogues tested, five produced neuropathy. In decreasing order of potency as assessed by the rotated performance test, these were as follows: acrylamide greater than N-isopropylacrylamide greater than N-methylacrylamide = methacrylamide greater than N-hydroxymethylacrylamide. The development of neurotoxicity was either greatly reduced or delayed by phenobarbital treatment. Acrylamide, N-hydroxymethylacrylamide, N-isopropylacrylamide, N-methylacrylamide and N,N'-methylene-bis-acrylamide produced testicular atrophy. Atrophy was either prevented by phenobarbital treatment, as in the cases of acrylamide and N-isopropylacrylamide, or reduced, as in the case of N-hydroxymethylacrylamide. Histological changes in the testis produced by the active compounds were degenerations of the epithelial cells of the seminiferous tubules, with the interstitial cells being normal.

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PubMed1990

Microbial degradation of acrylamide monomer.

Acrylamide, a neurotoxic monomer with extensive industrial applications was found to be degraded by the microorganisms present in a tropical garden soil. A bacterium capable of degrading acrylamide was isolated from this soil by enrichment. It was found to be aerobic, gram-negative, motile, short rod and identified as Pseudomonas sp. The bacterium degraded high concentrations of acrylamide (4 g/l) to acrylic acid and ammonia which were utilized as sole carbon and nitrogen source for growth. An amidase was involved in the hydrolysis of acrylamide, which could act on other short chain amides like formamide and acetamide but not on acrylamide analogues: methacrylamide and N,N-methylene bisacrylamide. The enzyme was sensitive to catabolite repression by succinate both in presence as well as absence of nitrogen source.

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PubMed1983

Neurotoxicity of acrylamide and related compounds in rats. Effects on rotarod performance, morphology of nerves and neurotubulin.

Neurotoxic properties of acrylamide and seven related compounds in rats were studied with regard to the effects on rotarod performance, morphology of nerves and neurotubulin. Compounds used in the present study were acrylamide, N-hydroxymethylacrylamide, N-isopropylacrylamide, methacrylamide, N-methylacrylamide, crotonamide, diacetone acrylamide, and N-tert-butylacrylamide. Animals were given chemicals in their drinking water for 90 days. Deficit of rotarod performance was produced by five compounds; acrylamide, N-hydroxymethylacrylamide, N-isopropylacrylamide, methacrylamide, and N-methylacrylamide. Morphological changes in tibial and sural nerves, such as shrinkage and loss of myelinated fibres, myelin retraction, and corrugated myelin sheaths, were observed after treatment with these five compounds. Depression of the [3H]colchicine-binding to neurotubulin (the soluble protein) of sciatic nerves was detected after giving these five compounds. After acrylamide dosing, the depression progressed with time. A significant reduction of the colchicine-binding to neurotubulin was also detected in the spinal cord of both the cervical and the lumbar regions, but neither in the brain nor the cerebellum.

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PubMed1981

'Acrylamide-induced' neuropathy and impairment of axonal transport of proteins. I. Multifocal retention of fast transported proteins at the periphery of axons as revealed by light microscope radioautography.

The axonal transport of proteins was studied in ciliary ganglia of control and acrylamide-treated chickens. After an intracerebral injection of [3H]lysine, the distribution of axonally transported proteins was analyzed in the preterminal segments of preganglionic axons and in their caliciform nerve endings by means of quantitative light microscope radioautography. By 7 days after the injection of [3H]lysine, the concentration of labeled proteins in the preganglionic axons was either similar or slightly increased in acrylamide-treated chickens as compared to controls. In contrast, by 3 h, whereas the axons of controls were poorly radioactive, 20-30% of the axons in acrylamide-treated chickens displayed focal and intense labeling at their periphery; simultaneously, in acrylamide treated chickens, 20-30% of the nerve endings contained a decreased amount of radioactive proteins. It is concluded that acrylamide induces multifocal retention of fast axonally transported proteins in preterminal segments of certain axons.

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PubMed1985

Mutagenicity of acrylamide and its analogues in Salmonella typhimurium.

Acrylamide and its 15 analogues have been tested for mutagenicity in 5 TA strains of Salmonella typhimurium. Acrylamide, N-tert-butylacrylamide, crotonamide, diacetone acrylamide, N,N-diethylacrylamide, N,N-dimethylacrylamide, N-hydroxymethylacrylamide, N-methylacrylamide, N-isobutoxymethylacrylamide, N-isopropylacrylamide, methacrylamide, N,N'-methylene-bis-acrylamide and N-tert-octylacrylamide appeared not to be mutagenic in the standard Ames assay both with and without Aroclor 1254-induced S9, and in both the plate incubation and liquid preincubation procedures. Three epoxide analogues, i.e., glycidamide, N,N-diglycidyl acrylamide and glycidyl methacrylamide showed mutagenicity in one or two strains both with and without the S9.

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PubMed1983

Distribution of 14C-labelled acrylamide and betaine in foetuses of rats, rabbits, beagle dogs and miniature pigs.

[14C]Acrylamide and [14C]betaine hydrochloride were administered in a single iv dose to pregnant rats, rabbits, beagle dogs and miniature pigs late in gestation (1-2 days before expected parturition). Dosages used were 10 mg/kg for rats and 5 mg/kg for the other species. The compounds were allowed to equilibrate in the animal (for 1 hr in rats and for 2 hr in the other species); the dam was then killed and the foetuses were removed by caesarean section. Each foetus was weighed and analysed for radioactivity, either by homogenization of the whole foetus (rat and rabbit) or by determining separately the radioactivity in individual organs and tissues (dog and pig). Foetal uptake of the polar compound betaine hydrochloride was much lower than that of the more lipophilic acrylamide. The sex of the foetus did not appear to affect uptake of either compound. There were no significant differences in total uptake of isotope attributable to the position of the foetus within the uterus in any of the four species given either acrylamide or betaine. Similarly, uterine position did not affect the uptake of acrylamide or betaine by individual tissues of foetal dogs or pigs. Since the distributions of 14C-labelled acrylamide and betaine hydrochloride were essentially uniform throughout a litter, it would not be necessary to sample all of the members of a litter to obtain a representative picture of foetal distribution.

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PubMed2006

Novel voltammetric biosensor for determining acrylamide in food samples.

Recent findings showing that acrylamide is formed in heat-treated foods rich in asparagine and reducing sugars such as glucose, have accelerated the needs for the development of new analytical methods to determine this potential human carcinogen. Acrylamide forms adduct with hemoglobin (Hb) as a result of the reaction with the alpha-NH2 group of N-terminal valine of Hb. This interaction is the basis of a new voltammetric biosensor to detect acrylamide. The biosensor was constructed using a carbon-paste electrode modified with hemoglobin (Hb), which contains four prosthetic groups of heme--Fe(III). Such an electrode displays a reversible reduction/oxidation process of Hb-Fe(III)/Hb-Fe(II). Interaction between Hb and acrylamide was observed through decreasing of the peak current of Hb-Fe(III) reduction. The electrodes presented a very low detection limit (1.2 x 10(-10)M). The validation made in the matrix obtained by water extraction of potato chips showed that the electrodes presented are suitable for the direct determination of acrylamide in food samples.

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PubMed2004

Trace level determination of acrylamide in cereal-based foods by gas chromatography-mass spectrometry.

A quantitative method has been developed for the determination of trace levels (<50 microg/kg) of acrylamide in cereal-based foods. The method is based on extraction of acrylamide with water, acidification and purification with Carrez I and II solutions, followed by bromination of the acrylamide double bond. The reaction product (2,3-dibromopropionamide) is extracted with ethyl acetate/hexane (4:1, v/v), dried over sodium sulfate, and cleaned up through a Florisil column. The derivative is then converted to 2-bromopropenamide by dehydrobromination with triethylamine and analyzed by gas chromatography coupled to mass spectrometry (GC-MS), employing (13C3)acrylamide as internal standard. In-house validation data for commercial and experimental cereal products showed good precision of the method, with repeatability and intermediate reproducibility relative standard deviations below 10%. The limit of detection and limit of quantitation are estimated at 2 and 5 microg/kg, respectively, and recoveries of acrylamide from samples spiked at levels of 5-500 microg/kg ranged between 93 and 104% after correction of analyte loss by the internal standard. Finally, a comparative test organized with two independent laboratories provided additional confidence in the good performance of the method, particularly at very low concentration levels.

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PubMed2005

Determination of acrylamide in potato chips and crisps by high-performance liquid chromatography.

A simple and rapid method using liquid chromatography coupled to diode array detection (LC-DAD) was developed for the determination of acrylamide in potato-based foods at low levels. The method entails extraction of acrylamide with methanol, purification with Carrez I and II solutions, evaporation and solvent change to water, and cleanup with a Oasis HLB solid-phase extraction (SPE) cartridge. The final extract was analyzed by LC-DAD for quantification and by liquid chromatography coupled to mass spectrometry (LC-MS) for confirmation. The chromatographic separations were performed on a hydrophilic and a hydrophobic interaction columns having good retention of acrylamide under 100% aqueous flow conditions (k' 3.67 and 2.54, respectively). The limit of quantitation was estimated to be 4.0 microg/kg based on the signal-to-noise ratio of 3 recorded at 226 nm. Recoveries of acrylamide from potato chips samples spiked at levels of 250, 500 and 1000 (n = 4 for each level) microg/kg ranged between 92.8 and 96.2% with relative standard deviations of less than 5%. The results of this study revealed that a conventional LC instrument coupled to DAD can also be used accurately and precisely, as an alternative to tandem LC-MS methods for the determination of acrylamide in potato-based foods.

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PubMed2005

Occurrence and analytical methods of acrylamide in heat-treated foods. Review and recent developments.

In early 2002, Swedish National Food Administration (SNFA) and University of Stockholm together announced that certain foods that are processed or cooked at high temperature contain relatively high levels of acrylamide. The occurrence of acrylamide is derived from heat-induced reactions between the amino group of asparagine and the carbonyl group of reducing sugars during baking and frying. Corresponding chromatographic methods are used to determine various structural groups present during this process. Gas chromatography (GC)-mass spectrometry (MS) and liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis are both acknowledged as the major useful and authoritative methods for the acrylamide determination and other chromatographic methods are also briefly introduced. The aim of this review is to summarize the state-of-the-art about the occurrence, analytical methods, and extraction and clean-up procedures of acrylamide. Special attention is given to chromatographic techniques applied for the occurrence and determination of acrylamide.

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PubMed2004

Acrylamide and cancer risk--expert risk assessments and the public debate.

This study has two parts. In the first part, fourteen carcinogen risk assessments of acrylamide made by different expert groups during the years 1976-2002 are compared in terms of their overall conclusions and their use of primary data. In the second part, the public debate on acrylamide and cancer risks and the questioning of the expert risk assessment, that arose as a reaction to the identification of this substance in staple food is discussed. In the first part it is shown that the expert risk assessors concur to a large degree about the assessment of the acrylamide potential to cause cancer. Three risk assessors have concluded that acrylamide is neither carcinogenic to humans nor to animals, while eleven risk assessors have concluded that acrylamide is carcinogenic in animals and is likely to be carcinogenic in humans. The differences in the overall conclusions seem to a large extent be explained by an evolving database. The risk assessors agree considerably on how to interpret and evaluate the available primary data, but the coverage of the available references is low. These results are also compared to those previously published on risk assessments of trichloroethylene. In the second part the arguments used in the public debate to question the expert risk assessment are summarized and it is argued that they are not based on the principles generally accepted in toxicological risk assessment.

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PubMedDate not supplied

Toxicological effects of acrylamide on rat testicular gene expression profile.

Toxicological effects of acrylamide on differential gene expression profile of rat testis were evaluated. Acrylamide induced morphological sperm defects, and decreased sperm concentration in cauda epididymis. Serum testosterone level and Leydig cell viability were also decreased dose-dependently, which resulted in decreased spermatogenesis. Acrylamide-induced histopathological lesions, such as formation of multinucleated giant cells and vacuolation, and numerous apoptotic cells were observed in seminiferous tubules. cDNA microarray analysis revealed that genes related to testicular-functions, apoptosis, cellular redox, cell growth, cell cycle, and nucleic acid-binding were up/down-regulated in testes isolated from acrylamide-treated group (60 mg/kg/day). Acrylamide toxicity appears to increase Leydig cell death and perturb gene expression levels, contributing to sperm defects and various abnormal histopathological lesions including apoptosis in rat testis.

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PubMed1981

Determination of acrylamide in nerve tissue homogenates by electron-capture gas chromatography.

Acrylamide in biological samples can be determined by gas chromatography with electron-capture detection after conversion to its 2,3-dibromopropionamide derivative. The derivatization is carried out in aqueous solution, plasma or tissue homogenates by ionic bromination and the reaction conditions and sample clean-up are described. The detection limit corresponds to 9.5.10(-12)g of acrylamide on column or 8.4.10(-9)g in the final biological extract (0.5 ml). The overall recovery of acrylamide spiked samples at the nanogram level exceeds 80%. It was found that the accumulation of free acrylamide in the sciatic nerve distal region of rats intoxicated with acrylamide was less than 2-8 ppm.

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PubMedDate not supplied

Effects of acrylamide on rodent reproductive performance.

Acrylamide monomer causes peripheral neurotoxicity, mutagenicity, clastogenicity, male reproductive toxicity, prenatal lethality, and endocrine-related tumors in rodents. Acrylamide (and/or its metabolite glycidamide) binds to dopamine receptors and spermatid protamines and inhibits activity of kinesin and dyneine, resulting in interference with neuronal intracellular transport and sperm motility. Glycidamide binds to various proteins and DNA. Acrylamide at low doses decreases litter size, with rats more sensitive than mice. At higher doses, sperm morphology and motility and neurotoxicity are affected, which decreases mating frequency. Acrylamide does not affect female reproduction (females exhibit neurotoxicity). Dominant lethal mutations cause decreased newborn litter size. The mechanisms of action appear to be: (1) acrylamide/glycidamide binding to spermatid protamines, causing dominant lethality and effects on sperm morphology; and (2) acrylamide binding to motor proteins, causing distal axonopathy, including hindlimb weakness/paresis, and effects on mounting, sperm motility, and intromission. Glycidamide-induced mutations appear to play no role in reproductive or neurologic toxicity.

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PubMed2003

Potential of acrylamide formation, sugars, and free asparagine in potatoes: a comparison of cultivars and farming systems.

Glucose, fructose, sucrose, free asparagine, and free glutamine were analyzed in 74 potato samples from 17 potato cultivars grown in 2002 at various locations in Switzerland and different farming systems. The potential of these potatoes for acrylamide formation was measured with a standardized heat treatment. These potentials correlated well with the product of the concentrations of reducing sugars and asparagine. Glucose and fructose were found to determine acrylamide formation. The cultivars showed large differences in their potential of acrylamide formation which was primarily related to their sugar contents. Agricultural practice neither influenced sugars and free asparagine nor the potential of acrylamide formation. It is concluded that acrylamide contents in potato products can be substantially reduced primarily by selecting cultivars with low concentrations of reducing sugars.

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PubMed2004

Acrylamide in French fries: influence of free amino acids and sugars.

The free amino acid profile and sugar (fructose, glucose, and sucrose) composition were determined in potato samples selected to give a large range of variation (a total of 66 samples). From these samples French fries were produced in a laboratory-scale simulation of an industrial process followed by a finish fry at 180 degrees C for 3.5 min using a restaurant fryer. The final product was blast frozen and analyzed for acrylamide. Acrylamide was detected in all samples, but its concentration varied significantly from 50 to 1800 ng/g. For isotope dilution (13C3) acrylamide analysis, samples were extracted with water, cleaned up on HLB Oasis polymeric and Accucat mixed mode anion and cation exchange SPE columns, and analyzed by LC-MS/MS. Statistical analysis of the data indicates that the effect of sugars and asparagine on the concentration of acrylamide in French fries is positive and significant (p < 0.001). It appears that one of the ways acrylamide formation in French fries can be effectively controlled is by the use of raw products with low sugar (and to a lesser degree, asparagine) content.

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PubMed2005

Sources of variability of acrylamide levels in a cracker model.

Surveys determining amounts of acrylamide formed as a byproduct of cooking in frequently consumed fried and baked foods have sometimes found variability in the levels, even when comparing items having similar ingredients and cooking procedures. To better understand the sources of variability, the effects of different ingredients on formation and elimination of acrylamide were studied in a model system based on wheat flour and water, that resembled crackers. It was found that NaHCO3 eliminated acrylamide. To a lesser extent, NH4HCO3, cysteine, sodium bisulfite, and ascorbate also enhanced elimination. Some ingredients, including citric acid, ferulic acid, and NaCl, were found to decrease the amount of acrylamide produced while having little or no effect on elimination. Asparagine, but not reducing sugar, caused a large increase in acrylamide formation.

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PubMed2005

Factors influencing acrylamide content and color in rye crisp bread.

An industrial baking procedure for yeast-leavened whole-grain rye crisp bread was adapted to local laboratory conditions to study the effect of time and temperature of baking and the addition of fructose, asparagine, and oat-bran concentrate on the acrylamide content and color of the bread. Baking time and temperature affected acrylamide content that increased from 10 to 30 mug/kg of bread at the combination of a long time and high temperature, with a significant interaction between the two factors (p < 0.008). Added asparagine had a significant effect (p < 0.001) on the formation of acrylamide, but fructose did not. There was a correlation between acrylamide content and color of the milled bread in the time-temperature experiment, but this correlation was not observed in the experiment with added precursors. Added oat-bran concentrate with high content of mixed-linkage beta-glucan did not influence the acrylamide content in the breads.

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