A new pathway of acrolein metabolism in rats

Inhibition of acrolein-induced apoptosis by the antioxidant selenium

In this study, the effects of a potent antioxidant, selenium, on apoptosis induced by acrolein, a cytotoxic and genotoxic environmental pollutant, were investigated by immunohistochemical and electron microscopic methods. One hundred adult male Wistar albino rats were used in the study. The rats were divided into four main groups: control, acrolein, selenium, and acrolein + selenium. The animals in the experimental groups were given 1 mg/kg/day selenium and 4 mg/kg/day acrolein daily for 7 days by gavage. After drug administration, each group was divided into subgroups according to the time they were to be euthanized: 12th hour, 1st, 2nd, 3rd, and 5th day. The rats in each group at the determined time were euthanized and their livers were removed. Routine histological procedures were performed for light and electron microscopy examinations. After applying the Terminal Deoxynucleotidyl Transferase dUTP nick end labeling assay on the liver sections, apoptotic index values were calculated. Comparing the liver sections of the rats in the acrolein group and the control group, acrolein was found to cause a significant increase in the apoptotic index. The apoptotic index values of the acrolein + selenium group decreased compared to the acrolein group. In the electron microscopic examinations, apoptotic findings were observed in the liver tissues of the rats given acrolein, such as chromatin condensation in the nucleus of hepatocytes, dilatations in the perinuclear space, and cytoplasmic vacuolization. These apoptotic findings were not observed in the acrolein + selenium group after the 12th hour. These findings show that selenium may potentially be useful as a protective agent for people exposed to acrolein.

Oncogenicity Study of Acrolein in Mice

Five hundred seventy CD-1 mice were divided equally by gender and assigned to three groups of 70 per gender and one group of 75 per gender. The first three groups were dosed via oral intubation at 0, 0.5, and 2.0 mg/kg/day while the larger groups were dosed at 4.5 mg/kg/day. Observations were made twice daily and blood smears taken at 12 and 18 months. All animals were sacrificed at 18 months; organs were weighed and examined grossly and microscopically. Treated animals showed decreased body weight gain and male mice demonstrated increased mortality, particularly at the high-dose level. Gross and microscopic lesions were not obviously dose dependent. In this study, acrolein was not shown to have oncogenic properties.

Acrolein health effects

Acrolein is a chemical used as an intermediate reactive aldehyde in chemical industry. It is used for synthesis of many organic substances, methionine production, and methyl chloride refrigerant. The general population is exposed to acrolein via smoking, second-hand smoke, exposure to wood and plastic smoke. Firefighters and population living or working in areas with heavy automotive traffic may expose to higher level of acrolein via inhalation of smoke or automotive exhaust. Degradation of acrolein in all environmental media occurs rapidly, therefore, environmental accumulation is not expected. Acrolein degrade in 6A days when applied to surface water, and it has not been found as a contaminant in municipal drinking water. Acrolein vapor may cause eye, nasal and respiratory tract irritations in low level exposure. A decrease in breathing rate was reported by volunteers acutely exposed to 0.3A ppm of acrolein. At similar level, mild nasal epithelial dysplasia, necrosis, and focal basal cell metaplasia have been observed in rats. The acrolein effects on gastrointestinal mucosa in the animals include epithelial hyperplasia, ulceration, and hemorrhage. The severity of the effects is dose dependent. Acrolein induces the respiratory, ocular, and gastrointestinal irritations by inducing the release of peptides in nerve terminals innervating these systems. Levels of acrolein between 22 and 249 ppm for 10 min induced a dose-related decrease in substance P (a short-chain polypeptide that functions as a neurotransmitter or neuromodulator).

Metabolism and distribution of [2,3-(14)C]acrolein in lactating goats

The metabolism and distribution of [2,3-(14)C]acrolein were studied in a lactating goat orally administered 0.82 mg/kg of body weight/day for 5 days. Milk, urine, feces, and expired air were collected. The goat was killed 12 h after the last dose, and edible tissues were collected. The nature of the radioactive residues was determined in milk and tissues. All of the identified metabolites were the result of the incorporation of acrolein into the normal, natural products of intermediary metabolism. There was evidence that the three-carbon unit of acrolein was incorporated intact into glucose, and subsequently lactose, and into glycerol. In the case of other natural products, the incorporation of radioactivity appeared to result from the metabolism of acrolein to smaller molecules followed by incorporation of these metabolites into the normal biosynthetic pathways.

Metabolism and distribution of [2,3-(14)C]acrolein in laying hens

The metabolism and distribution of [2,3-(14)C]-acrolein were studied in 10 laying hens orally administered 1.09 mg/kg of body weight/day for 5 days. Eggs, excreta, and expired air were collected. The hens were killed 12-14 h after the last dose and edible tissues collected. The nature of radioactive residues was determined in tissues and eggs. All of the identified metabolites were the result of the incorporation of acrolein-derived radioactivity into normal natural products of intermediary metabolism in the hen except for 1,3-propanediol, which is a known degradation product of glycerol in bacteria.

High-performance liquid chromatographic-tandem mass spectrometric determination of 3-hydroxypropylmercapturic acid in human urine

A sensitive and specific high-performance liquid chromatographic-tandem mass spectrometric (HPLC-MS-MS) method was developed for the determination of 3-hydroxypropylmercapturic acid (3-HPMA) in human urine. Samples were extracted using ENV+ cartridges and then injected onto a C8 Superspher Select B column with acetonitrile and formic acid as eluent (5:95, v/v). N-Acetylcysteine was used as internal standard for HPLC-MS-MS. Linearity was given in the tested range of 50-5000 ng/ml urine. The limit of quantification was 50 ng/ml. Precision, as C.V., in the tested range of 50-5000 ng/ml was 1.47-6.04%. Accuracy ranged from 87 to 114%. 3-HPMA was stable in human urine at 37 degrees C for 24 h. The method was able to quantify 3-HPMA in urine of non-smokers and smokers.

In vivo absorption, metabolism, and urinary excretion of alpha,beta-unsaturated aldehydes in experimental animals. Relevance to the development of cardiovascular diseases by the dietary ingestion of thermally stressed polyunsaturate-rich culinary oils

Thermal stressing of polyunsaturated fatty acid (PUFA)- rich culinary oils according to routine frying or cooking practices generates high levels of cytotoxic aldehydic products (predominantly trans-2-alkenals, trans,trans-alka-2,4-dienals, cis,trans-alka-2, 4-dienals, and n-alkanals), species arising from the fragmentation of conjugated hydroperoxydiene precursors. In this investigation we demonstrate that typical trans-2-alkenal compounds known to be produced from the thermally induced autoxidation of PUFAs are readily absorbed from the gut into the systemic circulation in vivo, metabolized (primarily via the addition of glutathione across their electrophilic carbon-carbon double bonds), and excreted in the urine as C-3 mercapturate conjugates in rats. Since such aldehydic products are damaging to human health, the results obtained from our investigations indicate that the dietary ingestion of thermally, autoxidatively stressed PUFA-rich culinary oils promotes the induction, development, and progression of cardiovascular diseases.

Fate and effects of acrolein

Acrolein is a highly toxic, reactive, and irritating aldehyde that occurs as a product of organic pyrolysis, as a metabolite of a number of compounds, and as a residue in water when used for the control of aquatic organisms. It is an intermediate in the production of acrylic acid, DL-methionine, and numerous other agents. Its major direct use is as a biocide for the control of aquatic flora and fauna. It is introduced to the environment from a variety of sources, including organic combustion such as automobile exhaust, cigarette smoke, and manufacturing and cooking emissions, as well as direct biocidal applications. Organic combustion from both fixed and mobile sources is the significant source of acrolein in the atmosphere; it represents up to 8% of the total aldehydes generated from vehicles and residential fireplaces and 13% of total atmospheric aldehydes. This reactive aldehyde also occurs in organisms as a metabolite of allyl alcohol, allylamine, spermine, spermidine, and the anticancer drug cyclophosphamide, and as a product of UV radiation of the skin lipid triolein. Furthermore, small amounts are found in foods; when animal or vegetable fats are overheated, however, large amounts are produced. Most human contact occurs during exposure to smoke from cigarettes, automobiles, industrial processes, and structural and vegetation fires. Besides cigarette smoke, occupational exposures are a common mode of human contact, particularly in industries that involve combustion of organic compounds. Firefighters, in particular, are exposed to extremely high levels during the extinguishment and overhaul phases of their work. Water may contain significant levels of the herbicide. It has been found in paper mill and municipal effluents at 20-200 micrograms/L, and at 30 micrograms/L as far as 64 km downstream from the point of application. The USEPA-recommended water quality criteria for freshwater are only 1.2 micrograms/L (24-hr avg) and 2.7 micrograms/L (maximum ceiling). Acrolein is highly reactive, and intercompartmental transport is limited. However, it is eliminated from aqueous environments by volatilization and hydration to beta-hydroxypropanal, after which biotransformation occurs, with a half-life of 7-10 d. The Koc for acrolein is 24, and it is not likely to be retained in soil; activated carbon adsorbs only 30% from solution. Thus, the aldehyde is either leached extensively in moist soil or volatilizes quickly from dry soil. It is eliminated from air by reaction with .OH (half-life, 0.5-1.2 d), NOx (half-life, 16 d), and O3 (half-life, 59 d), as well as by photolysis and wet deposition. As expected from its high water solubility, bioaccumulation is low. Acrolein is highly toxic by all routes of exposure. The respiratory system is the most common target: exposure causes localized irritation, respiratory distress, pulmonary edema, cellular necrosis, and increased susceptibility to microbial diseases. Additionally, acute inhalation studies verify that it is a severe respiratory irritant that affects respiratory rates. Respiratory rate depression may have a protective effect by minimizing vapor inhalation, thereby explaining the subadditive effect of acrolein when combined with the other toxic combustion by-products CO and HCHO. Liquid contact with the skin and eyes causes severe irritation, opaque or cloudy corneas, and localized epidermal necrosis, but no allergic contact dermatitis. The cardiovascular system is affected, resulting in increased blood pressure, platelet aggregation, and quick cessation of beating in perfused rat hearts. It may also inhibit mitochondrial oxidative phosphorylation in the myocardium. Acute LD50s and LC50s are low. Levels are 7-46 mg/kg and 18-750 mg/m3, respectively, in rats; aquatic organisms are affected above 11.4 micrograms/L.(ABSTRACT TRUNCATED)

Acrolein genotoxicity in Drosophila melanogaster. III. Effects of metabolism modification

In order to investigate the role of metabolism in acrolein genotoxicity in D. melanogaster, the action of several metabolism modifiers, namely phenobarbital, an inducer of xenobiotic metabolism, phenylimidazole and iproniazid, inhibitors of oxidative activities of cytochrome P450, and diethyl maleate, a glutathione-depleting agent, have been assayed using the sex-linked recessive lethal (SLRL) test, with two different administration routes (feeding and injection). The results support the hypothesis that acrolein is not only a direct mutagen but is also transformed, by oxidative activities of cytochrome P450 after glutathione conjugation, into an active metabolite, possibly glycidaldehyde. Moreover, acrolein is deactivated by an enzymatic activity induced by phenobarbital.

Nephrotoxicity of the 1:1 acrolein-glutathione adduct in the rat

Previous metabolic studies in rats have suggested in vivo formation of the acrolein-glutathione (acrolein-GSH) adduct following administration of the highly reactive alpha, beta-unsaturated aldehyde acrolein. Early studies by several investigators demonstrated that similar compounds such as alpha, beta-unsaturated aldehyde-cysteine adducts have toxic (carcinostatic) activity against Ehrlich ascites tumor cells implanted in mice. The current studies investigated the in vivo toxicity associated with the acrolein-GSH adduct in the male Sprague-Dawley rat. The 1:1 acrolein-GSH adduct was synthesized and characterized by physical-chemical methods. Rats given the acrolein-GSH adduct intravenously at 0.5 or 1 mmol/kg developed nephrotoxicity characterized by glucosuria, proteinuria, elevation in serum urea nitrogen, and gross and histologic changes of the kidney. The toxicity was not affected by pretreatment of rats with pyrazole, an alcohol dehydrogenase inhibitor; disulfiram, an inhibitor of aldehyde dehydrogenases; or probenecid, a renal organic anion transport inhibitor. Administration of a similar but nonaldehydic glutathione conjugate, S-n-propylglutathione, did not result in nephrotoxicity in the rat. The nephrotoxicity induced by the acrolein-GSH adduct was inhibited by acivicin, a gamma-glutamyl-transpeptidase inhibitor. These results indicate that the acrolein-GSH adduct requires processing through the first step of the renal mercapturic acid synthesis pathway to be activated to a toxic species.

One-year toxicity of orally administered acrolein to the beagle dog

Forty-eight dogs were separated into four groups of six males and six females. Acrolein (0.1% aqueous) was administered in gelatin capsules to three of these groups at dosing levels of 0.1, 0.5 and 1.5 mg kg-1 day-1 based on results of a range-finding study. After 4 weeks, the high dose was increased to 2 mg kg-1 day-1. The fourth group received deionized water in the same number of gelatin capsules as the high-dose group. Dosing was 7 days per week for 53 weeks. Blood and biochemical measurements were made pretest and at 3-month intervals thereafter. At termination, all dogs were subjected to full necropsy and histological examination. The major test effect noted was frequent vomiting after dosing. This was observed to be dose-dependent and the frequency decreased with time, indicating an adaptive effect. One mid-dose female died during the test and was diagnosed as having died of severe bronchial pneumonia, probably a result of vomitus aspiration. Serum albumin, calcium and total protein values were depressed in high-dose animals throughout the study. Some variability in red blood cell parameters and coagulation times were noted but the significance of these effects was not obvious.

Two-year toxicity and carcinogenicity study of acrolein in rats

Five-hundred and sixty Sprague-Dawley rats were randomized into one control and three treatment groups (70 of each sex per group). Animals were treated by daily gavage with 0.0, 0.05, 0.5 and 2.5 mg kg-1 acrolein in water (10 ml kg-1). These dosing levels were selected as a result of a 6-week range-finding study. Ten rats of each sex per group were sacrificed at 1 year, and the remainder of the animals were treated for 102 weeks. Daily observations wer made, and various clinical, hematological and urine parameters were measured after 3, 6, 12 and 18 months of treatment and immediately prior to termination. All animals, whether found dead or sacrificed, were subject to necropsy and both absolute and relative organ weights were recorded. An extensive array of tissues were examined microscopically for all test animals. The only effects noted for treated rats that were statistically different from controls were consistent depression of creatinine phosphokinase levels, which was difficult to explain, and consistent increases in early cumulative mortalities in both males and females. There was no significantly increased incidence of microscopic lesions in treated rats, whether neoplastic or non-neoplastic. This study clearly demonstrates the lack of neoplastic response in Sprague-Dawley rats as a result of being treated with acrolein by gavage.

Mercapturic acids, protein adducts, and DNA adducts as biomarkers of electrophilic chemicals

The possibilities and limitations of using mercapturic acids and protein and DNA adducts for the assessment of internal and effective doses of electrophilic chemicals are reviewed. Electrophilic chemicals may be considered as potential mutagens and/or carcinogens. Mercapturic acids and protein and DNA adducts are considered as selective biomarkers because they reflect the chemical structure of the parent compounds or the reactive electrophilic metabolites formed during biotransformation. In general, mercapturic acids are used for the assessment of recent exposure, whereas protein and DNA adducts are used for the assessment of semichronic or chronic exposure. 2-Hydroxyethyl mercapturic acid has been shown to be the urinary excretion product of five different reactive electrophilic intermediates. Classification of these electrophiles according to their acid-base properties might provide a tool to predict their preference to conjugate with either glutathione and proteins or with DNA. Constant relationships appear to exist in the cases of 1,2-dibromoethane and ethylene oxide between urinary mercapturic acid excretion and DNA and protein adduct concentrations. This suggests that mercapturic acids in some cases may also play a role as a biomarker of effective dose. It is concluded that simultaneous determination of mercapturic acids, protein and DNA adducts, and other metabolites can greatly increase our knowledge of the specific roles these biomarkers play in internal and effective dose assessment. If the relationship between exposure and effect is known, similar to protein and DNA adducts, mercapturic acids might also be helpful in (individual) health risk assessment.

Acrolein genotoxicity in Drosophila melanogaster. I. Somatic and germinal mutagenesis under proficient repair conditions

The genotoxicity of acrolein in D. melanogaster was investigated using 2 different SMART assays, the eye spot and wing spot tests, and 2 germinal tests, the sex-linked recessive lethal (SLRLT) and sex chromosome loss (SCLT) tests. For the 2 latter, exposure by feeding as well as injection was used. The results indicate that: (i) acrolein is mutagenic in the SLRLT when injected but not when fed; (ii) the SCLT did not reveal clastogenic effects; (iii) acrolein had genotoxic effects in both SMART assays; (iv) we also had several indications that acrolein is metabolized into a second genotoxic product.

Gene mutation assay of acrolein in the CHO/HGPRT test system

The mutagenic potential of acrolein has been studied with a wide range of in vitro and in vivo genetic toxicity assays. The data often have been conflicting, especially with the Ames assay. This study was undertaken to assess the mutagenic potential of acrolein using the CHO/HGPRT assay, both with and without metabolic activation. This assay system was chosen because it provides eukaryotic DNA as the target and is capable of detecting a range of mutational events. Because of its considerable toxicity, acrolein was tested over a very narrow dose range of 0.2-2 nl ml-1 without exogenous activation and 0.5-8 nl ml-1 with rat S-9 activation. Multiple assays were performed under both conditions. The results indicated that while acrolein was clearly very cytotoxic, it did not induce a significant mutagenic response in the presence or absence of metabolic activation.

Chemistry and biochemistry of 4-hydroxynonenal, malonaldehyde and related aldehydes

Lipid peroxidation often occurs in response to oxidative stress, and a great diversity of aldehydes are formed when lipid hydroperoxides break down in biological systems. Some of these aldehydes are highly reactive and may be considered as second toxic messengers which disseminate and augment initial free radical events. The aldehydes most intensively studied so far are 4-hydroxynonenal, 4-hydroxyhexenal, and malonaldehyde. The purpose of this review is to provide a comprehensive summary on the chemical properties of these aldehydes, the mechanisms of their formation and their occurrence in biological systems and methods for their determination. We will also review the reactions of 4-hydroxyalkenals and malonaldehyde with biomolecules (amino acids, proteins, nucleic acid bases), their metabolism in isolated cells and excretion in whole animals, as well as the many types of biological activities described so far, including cytotoxicity, genotoxicity, chemotactic activity, and effects on cell proliferation and gene expression. Structurally related compounds, such as acrolein, crotonaldehyde, and other 2-alkenals are also briefly discussed, since they have some properties in common with 4-hydroxyalkenals.

The role of biotransformation in the genotoxicity of allylic compounds

Allylic compounds exert direct genotoxic activities which depend on the chemical nature of the leaving group and on further substituents. Besides the direct genotoxic effects, metabolic activation mechanisms are also conceivable. Epoxidation seems to play a minor role in bioactivation, whereas the metabolic formation of strongly mutagenic alpha, beta-unsaturated carbonyl compounds is obviously of great importance for the indirect genotoxicity of allylic compounds. Only in the case of 2,3-dichloro-1-propene is an epoxide formed which is extremely unstable and immediately rearranges to the strong mutagen, 1,3-dichloroacetone.

Biological conversion of benzaldehyde to benzylmercapturic acid in the Sprague-Dawley rat

The metabolism of benzaldehyde was investigated in Sprague-Dawley rats. After repeated oral administration of this compound (0.4-1.0 g/kg) for 13 consecutive days, urine was collected and analyzed for the presence of metabolites. The acidification of the pooled urine samples (pH:2.0) with 6 N H2SO4 was followed by ethyl acetate extraction, evaporation of the extract and methylation with diazomethane. Identification of the metabolite by comparison with a synthetic sample of benzylmercapturic acid (BENZM) was conducted by gas chromatography. Mass spectrometry examination of this metabolite revealed the following peaks characteristic of benzylmercapturic acid: m/z (%), 91(100), 176(27), 208(23), 43(20), 88(13), 117(10), 134(9), M+ 267(2). Monitoring of urines from both female and male rats showed a dose-related increase of benzylmercapturic acid which was found to be a reliable indicator of exposure to benzaldehyde.

Cyclophosphamide: interstrain differences in the production of mutagenic metabolites by S9-fractions from liver and kidney in different mutagenicity test systems in vitro and in the teratogenic response in vivo between CBA and C 57 BL mice

The formation of mutagenic compounds from cyclophosphamide (CPA) by S9-fractions from liver (S9L) or kidney (S9K) of pregnant CBA and C 57 BL mice was investigated, using point mutations in Salmonella typhimurium (TA 1535) and the induction of sister chromatid exchanges (SCE) in human peripheral lymphocytes (HPL) or Chinese hamster ovary (CHO) cells as end points. In addition, the teratological response of CBA and C 57 BL mice to CPA on day 11 of pregnancy was analysed in vivo. The results are as follows: (1) S9L from CBA mice was more effective than S9L from C 57 BL mice in metabolizing CPA to products inducing mutations in Salmonella and SCEs in HPL and CHO cells. (2) S9L was more effective than S9K from both strains of mice. (3) In vivo pretreatment of mice with a single dose of CPA (20 mg/kg) reduced the in vitro metabolizing capacity of S9L and S9K significantly and led to the disappearance of the interstrain difference. (4) The embryolethal and teratogenic effects of CPA were stronger in C 57 BL than in CBA mice; the types of teratological effects were partially different in the two strains.

The role of acrolein in allyl alcohol-induced lipid peroxidation and liver cell damage in mice

Male NMRI mice were fed a sucrose diet for 48 hr in order to reduce the hepatic glutathione content and to level off its diurnal variation. After administration of allyl alcohol (AA: 1.1 mmol/kg), hepatic glutathione (24.3 +/- 7.0 nmol GSH/mg protein) was almost totally lost within the first 15 min (less than 0.5 nmol GSH/mg protein). Subsequently, a massive lipid peroxidation was observed, i.e. the animals exhaled 414 +/- 186 nmol ethane/kg/hr compared to 0.9 +/- 0.8 of controls, and the hepatic TBA-reactive compounds had increased from 55 +/- 16 pmol/mg protein in controls to 317 +/- 163 after 1 hr. Concomitantly, a 40-45% loss of the polyunsaturated fatty acids (arachidonic and docosahexaenoic acid) in the liver lipids was observed. About 80% of the cytosolic alcohol dehydrogenase activity and about 50% of the microsomal P450-content were destroyed. In vivo-inhibition of alcohol dehydrogenase by pyrazole or induction of aldehyde dehydrogenase by phenobarbital abolished AA-induced liver damage as well as glutathione depletion and lipid peroxidation, while inhibition of aldehyde dehydrogenase by cyanamide made a subtoxic dose of AA (0.60 mmol/kg) highly toxic. These results strongly favour the importance of acrylic acid formation as an additional detoxification pathway. Enhanced hepatic levels of glutathione protected in vivo against the damaging effects of AA. Depletion of the liver glutathione content by phorone or diethylmaleate alone caused marginally enhanced lipid peroxidation (phorone) but not liver cell damage. Monooxygenase inhibitors (metyrapone, diethyldithiocarbamate, alpha-naphthoflavone) or an inducer (benz(a)pyrene) did not affect AA-induced toxicity. The ferric iron chelator desferoxaminemethanesulfonate prevented AA-induced lipid peroxidation and liver cell damage in vivo. In vitro, acrolein alone failed to initiate lipid peroxidation in soy bean phospholipid liposomes or in mouse liver microsomes. Thus, acrolein not only impairs the glutathione defense system but also directly destroys cellular proteins and evokes lipid peroxidation by an indirect iron-depending mechanism.

Examination of the differential hepatotoxicity of diallyl phthalate in rats and mice

In this study we confirmed that diallyl phthalate (DAP) is more hepatotoxic to rats than to mice, and we demonstrated the same species difference in toxicity for allyl alcohol (AA). The data suggest that the toxicity of DAP probably results from AA cleaved from DAP. To determine if the species difference in susceptibility to hepatotoxicity resulted from differences in the disposition and metabolism of DAP, Fischer-344 rats and B6C3F1 mice were given [14C]DAP, 1, 10, or 100 mg/kg po or 10 mg/kg iv, and placed in metabolism cages for 24 hr. In rats, 25-30% of the DAP was excreted as CO2, and 50-70% appeared in the urine within 24 hr. In mice, 6-12% of the DAP was excreted as CO2, and 80-90% was excreted in the urine within 24 hr. Monoallyl phthalate (MAP), allyl alcohol, 3-hydroxypropylmercapturic acid (HPMA), and an unidentified polar metabolite (PM) were found in the urine of rats and mice dosed with DAP. The polar metabolite was present in the urine of rats dosed with DAP or AA, indicating that the compound is a metabolite of AA. There was no difference between the species in the quantity of AA excreted, but mice excreted more MAP (39 vs 33%), HPMA (28 vs 17%), and PM (20 vs 8%) than rats. Because DAP is metabolized to AA, a potent periportal hepatotoxicant, and because the mouse produced more HPMA than rats, we postulate that the differential hepatotoxicity of DAP is related to the extent of glutathione conjugation with allyl alcohol or acrolein (the active metabolite of AA).

A critical review of the literature on acrolein toxicity

A detailed literature review of human and animal toxicity studies of acrolein is presented, and information gaps identified that call for further investigation. Specific recommendations are suggested for additional short-/long-term studies, including chemical disposition and cytogenetic investigations. Two bibliographies are provided indicating the scope of the review: (1) literature actually cited and (2) literature examined but not included.