Abstract Acrylamide Research Articles

Acrylamide disturbs genomic imprinting during spermatogenesis

Acrylamide (ACR), a carcinogen for rodents and humans, exists widely in the human living environment and heat-treated carbohydrate foodstuffs. Increasing evidence has demonstrated that ACR can cause chromosomal damage in somatic cells and mutagenesis. However, little is known about whether ACR can disturb genomic imprinting during spermatogenesis. We investigated the effects of ACR on methylation patterns of rat sperm genes. The results showed that after oral administration of ACR to rats for two weeks, methylation of some cytosines in the CpG islands of the differentially methylated region (DMR2) of sperm gene insulin-like growth factor II (Igf2), which is still present at the 19th day, disappeared on the 35th day. Furthermore, the extent by which ACR causes methylation defects varies in animals. Our findings indicate that mitotic spermatogonia and primary spermatocytes are sensitive to ACR-induced genomic imprinting aberration, suggesting that ACR predominantly interferes with the remodeling process in spermatogenesis.

Polymerization of Acrylamide in Aqueous Solution of Poly(N‐isopropylacrylamide) at Lower Critical Solution Temperature

Acrylamide (AAm) was found to polymerize in a solution of poly(N‐isopropylacrylamide) (PNIPAAm) in water at around its lower critical solution temperature (LCST) (32°C) without any initiators. This phenomenon was specifically observed in aqueous solutions of the polymers having LCST such as PNIPAAm and poly(methylvinylether) (PMVE). AAm polymerized only when PNIPAAm and AAm were dissolved in water below LCST of PNIPAAm and then the solution was warmed up to the polymerization temperature (40°C). On the other hand, the polymerization of AAm did not proceed when AAm was added into aqueous PNIPAAm solution during and after the phase separation above 32°C. Furthermore the polymerizability of AAm was remarkably affected by the concentration and molecular weight of the PNIPAAm additives. Under the condition of lower PNIPAAm concentration (0.30 mol/L), the increase in the molecular weight of PNIPAAm considerably increased the molecular weight of the resulting PAAm but decreased the yield of PAAm. Under the condition of higher PNIPAAm concentration (0.60 mol/L) the polymerizability was not so affected by the molecular weight of PNIPAAm, while the molecular weight of PAAm formed by using higher molecular weight PNIPAAm was higher than those of PAAm formed by using lower molecular weight PNIPAAm. Moreover, the molecular weight of PAAm formed by the PNIPAAm induced polymerization of AAm was much higher than that of the polymer obtained by the radical polymerization using AIBN in THF or VA‐ 061 in water.

Acrylamide-induced molecular mutation spectra at HPRT locus in human promyelocytic leukaemia HL-60 and NB4 cell lines

Acrylamide (AA) is a compound widely used in many industries around the world. The recent finding that it is formed naturally in foods by heating raises human health concerns. AA is a proven carcinogen in animals and a probable carcinogen in humans, while its mutagenicity detected using in vitro mammalian gene mutation assays is still inconsistent in different cell systems. In the present study, we investigated the mutagenicity of AA in human promyelocytic leukaemia cells, HL-60 and NB4 cells, by examining the mutations at the hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene locus. In a 6-h treatment without the exogenous activation, AA exerted a weak mutagenic effect at the highest concentration used in the study (700 mg/l) in HL-60 cells (P < 0.01) as well as in NB4 cells (P < 0.05). Molecular analysis of AA-induced mutants revealed a different mutation spectrum, when compared to that of spontaneous mutants. The most frequent spontaneous mutations were point mutations, whereas AA-induced mutations were mainly single exon deletions besides point mutations, and an increase in the proportion of partial deletion was associated with the increase of AA treatment. There was no obvious difference in the mutation spectra observed between the HL-60 and NB4 cell lines. These results showed that AA has a weak mutagenic effect at HPRT gene locus in human promyelocytic leukaemia HL-60 and NB4 cell lines and those molecular mutation spectra (single exon deletions and point mutations) may be related to some specific and precise mechanism.

The Changes of Cytoskeletal Proteins in Plasma of Acrylamide-Induced Rats

Acrylamide (ACR) is a known industrial neurotoxic chemical that can induce neurodegeneration. Cytoskeletal protein aggregation is a pathological hallmark of neurodegenerative disorders. This study was an initial exploration on cytoskeletal proteins in plasma as potential biomarkers of ACR neurotoxicity. Low and high ACR groups received 20 mg/kg and 40 mg/kg ACR by intraperitoneal injection in adult Wistar rats and control group received physiological saline. Rats were all killed after 8 weeks to evaluate the levels of neurofilament(NF)-L, NF-M, NF-H, beta-actin, alpha-tubulin, beta-tubulin, tau, MAP2 proteins in plasma using both SDS-PAGE and western blotting. Compared with the control, the levels of NF-L, NF-M, NF-H, beta-actin, tau, MAP2 proteins decreased and the level of alpha-tubulin increased in high ACR group, the levels of alpha-tubulin, beta-tubulin and MAP2 increased in low ACR group. The results suggested that the changes of these proteins might be relevant to the neurotoxicity of ACR. Some of the cytoskeletal proteins in plasma might be used as marker of biological effect in ACR induced neuropathy.

The effect of PEG(400)DA crosslinking agent on swelling behaviour of acrylamide-maleic acid hydrogels

Acrylamide (AAm)-maleic acid (MA) hydrogels with different monomer ratios were prepared in an aqueous solution by radical polymerization using a new crosslinking agent, polyethyleneglycol (400) diacrylate (PEG (400) DA) and also using N, N’-methylenebisacrylamide (NMBA) for comparison purpose. The hydrogels were characterized by acid group content and FTIR spectroscopy. Their swelling and deswelling behavior were studied as a function of maleic acid content, pH and crosslinking agent. Incorporation of MA in hydrogels significantly increased their swelling ability and their equilibrium degree of swelling (EDS) values changed between 100–269 g water/g polymer in water while AAm polymers swollen less (22–23 g water/g polymer). The AAm hydrogels showed Fickian type diffusion but the all AAm-MA hydrogels showed non-Fickian type behavior. Their swelling degree increased with the increase of pH of the external medium and an instantaneous increase was observed near a pH value of 7.0. The use of PEG (400) DA instead of NMBA as a crosslinking agent also increased the swelling rate and capacity of the gel. The swelling constant (K) and the diffusion coefficient (D) of hydrogels were also increased. The swelling-deswelling cycles in acidic-basic solutions showed that they could be used as pH responsive gels without any decrease in swelling capacity.

Adsorption of Uranyl Ions into Poly(Acrylamide‐co‐Acrylic Acid) Hydrogels Prepared by Gamma Irradiation

Acrylamide (AAm)/Acrylic Acid (AAc) copolymers have been prepared by gamma irradiation of binary mixtures at three different compositions where the acrylamide/acrylic acid mole ratios varied around 15, 20, and 30%. Threshold dose for 100% conversion of monomers into hydrogels was found to be 8.0 kGy. Poly(Acrylamide‐co‐Acrylic Acid) (poly(AAm‐co‐AAc)) hydrogels have been considered for the removal of uranyl ions from aqueous solutions. Swelling behavior of these hydrogels was determined in distilled water at different pH values and in aqueous solutions of uranyl ions. The results of swelling tests at pH 8.0 indicated that poly(AAm‐co‐AAc) hydrogel, containing 15% acrylamide showed maximum % swelling. Diffusion of water and aqueous solutions of uranyl ion into hydrogels was found to be non‐Fickian in character and their diffusion coefficients were calculated. The effect of pH, composition of hydrogel, and concentration of uranyl ions on the adsorption process were studied at room temperature. It was found that one gram of dry poly(AAm‐co‐AAc) hydrogel adsorbed 70–320 mg and 70–400 mg uranyl ions from aqueous solutions of uranyl nitrate and uranyl acetate in the initial concentration range of 50–1500 mg UO2 2+L−, depending on the amount of AAc in the hydrogels, respectively. Adsorption isotherms were constructed for poly(AAm‐co‐AAc)–uranyl ion system indicating an S type of adsorption in the Giles classification system. It is concluded that crosslinked poly(AAm‐co‐AAc) hydrogels can be successfully used for the removal of uranyl ions from their aqueous solutions.

Grafting copolymerization of acrylamides onto preirradiated PP films

Acrylamide (AAm), N,N-Dimethylacrylamide (DMAAm) and N-(3-Dimethylaminopropyl) methacrylamide (DMAPMAAm) were grafted onto polypropylene (PP) films by preirradiation grafting respectively. The effect of irradiation dose, solvent systems and reaction time on the degree of grafting were determined. The grafted sample films were verified by Fourier Transform Infrared (FTIR) spectroscopy in the attenuated total reflectance mode (ATR) and the determination of water contact angle. The blood compatibility of the grafted PP films were evaluated by the determination of platelet adsorption and thrombus. The blood compatibility of grafted PP films seems better than that of original PP films.

Effect of acrylamide toxicity on the ultrastructure of a single cell model Nyctotheroides puytoraci

Acrylamide (ACR), a widely used vinyl monomer, is well known as a neurotoxin to both laboratory animals and man. The experiment reported has demonstrated that ACR induces ultrastructural changes in the parasitic ciliate Nyctotheroides puytoraci, after injecting the host Bufo regularis with 1 mg ACR per toad (single dose). After 1 week of ACR injection, alterations in both nuclear and cytoplasmic organelles were observed. An increase in the number of cisternae of the Golgi complex was visualized which may be due to its division and hence activation. Acrylamide also appeared to cause fusion of mitochondria in the treated trophozoites. Thus trophozoites of these specimens showed a decreased number of irregularly shaped mitochondria with dense matrix and indistinct outer and inner membranes. Such changes may be attributed to a disturbance in mitochondrial protein synthesis. Also, rough endoplasmic reticulum and lysosomes increased in number. The basal cell bodies were degenerated at some sites.

Acrylamide alters oxidative enzyme activity in rat motoneurons

Acrylamide (ACR) produces a central-peripheral distal axonopathy, via an unknown mechanism. We have investigated the effects of ACR on the activity of enzymes responsible for the oxidation of NADH (NADH-tetrazolium reductase activity, NADH-TR) with quantitative histochemical techniques. Chronic (5- or 10-day) injection of ACR (50 mg/kg/day) resulted in a significant decrease in enzyme activity in soleus motoneurons, which normally have high NADH-TR activity. The NADH-TR activity in motoneurons with low oxidative metabolism was not significantly affected. Retrograde labeling of motoneurons with horseradish peroxidase was diminished by the acrylamide treatment. These data demonstrate an acrylamide-induced change in the oxidative metabolism of certain motoneurons; further study will determine whether oxidative metabolism is the primary site of action of ACR in producing the distal axonopathy.