NTP Technical Report on the comparative toxicity studies of allyl acetate (CAS No. 591-87-7), allyl alcohol (CAS No. 107-18-6) and acrolein (CAS No. 107-02-8) administered by gavage to F344/N rats and B6C3F1 mice.

Allyl acetate, allyl alcohol, and acrolein are used in the manufacture of detergents, plastics, pharmaceuticals, and chemicals and as agricultural agents and food additives. Male and female F344/N rats and B6C3F(1) mice received allyl acetate, allyl alcohol, or acrolein by gavage for 14 weeks. Genetic toxicology studies were conducted in Salmonella typhimurium, Drosophila melanogaster, cultured Chinese hamster ovary cells, rat bone marrow erythrocytes, and mouse peripheral blood erythrocytes. Groups of 10 male and 10 female rats were administered 0, 6, 12, 25, 50, or 100 mg allyl acetate/kg body weight, 0, 1.5, 3, 6, 12, or 25 mg/kg allyl alcohol, or 0, 0.75, 1.25, 2.5, 5, or 10 mg/kg acrolein in 0.5% methylcellulose by gavage, 5 days per week for 14 weeks. Groups of 10 male and 10 female mice were administered 0, 8, 16, 32, 62.5, or 125 mg/kg allyl acetate, 0, 3, 6, 12, 25, or 50 mg/kg allyl alcohol, or 0, 1.25, 2.5, 5, 10, or 20 mg/kg acrolein in 0.5% methylcellulose by gavage, 5 days per week for 14 weeks. In the allyl acetate rat study, all males and females in the 100 mg/kg groups died or were killed moribund by day 8; there were no other deaths. In the allyl alcohol study, all rats survived to the end of the study except one 6 mg/kg female. In the acrolein rat study, eight males and eight females in the 10 mg/kg groups died by week 9 of the study. Two males in the 2.5 and 5 mg/kg groups and one or two females in the 1.25, 2.5, and 5 mg/kg groups also died early; two of these deaths were gavage accidents. In the allyl acetate mouse study, all males and females in the 125 mg/kg group died during the first week of the study. All other early deaths, except five 62.5 mg/kg males and one 32 mg/kg female, were gavage accidents. In the allyl alcohol mouse study, one 50 mg/kg female died due to a gavage accident; all other animals survived to the end of the study. In the acrolein mouse study, all males and females administered 20 mg/kg died during the first week of the study. All other early deaths, except one male and one female administered 10 mg/kg, were unrelated to chemical administration. The concentration of 3-hydroxypropyl mercapturic acid (3-HPM) in the urine of rats and mice was determined after the first dose of chemical and at the end of the 14-week study. At both time points, the concentrations of 3-HPM in the urine of animals that received allyl acetate or allyl alcohol increased linearly with dose. In animals dosed with acrolein, the concentrations of 3-HPM exhibited a nonlinear increase with dose at the first time point. At the end of the study, the concentration of 3-HPM in the urine of animals dosed with acrolein was linear with dose except at the highest concentration administered. Since urine volumes were not recorded during the urine collection, complete quantitation of these data was not possible. The final mean body weights and mean body weight gains of male rats administered 12 or 50 mg/kg allyl acetate and of male and female rats administered 10 mg/kg acrolein were significantly less than those of the vehicle controls. The mean body weight gain of male mice in the 50 mg/kg group in the allyl alcohol study was also less than that of the vehicle controls. Final mean body weights and mean body weight gains of dosed female rats and male and female mice in the allyl acetate studies, male and female rats and female mice in the allyl alcohol studies, and male and female mice in the acrolein studies were generally similar to those of the respective vehicle controls. Clinical findings related to allyl acetate administration included pallor, eye or nasal discharge, ruffled fur, lethargy, diarrhea, and thinness among rats in the 100 mg/kg groups and lethargy, abnormal breathing, thinness, and ruffled fur among mice that died early. In the acrolein study, clinical findings included abnormal breathing, eye or nasal discharge, ruffled fur, thinness, and lethargy in rats in the 10 mg/kg groups. The liver weights of male rats administered 25 mg/kg allyl alcohol, female rats administered 50 mg/kg allyl acetate or 5 or 10 mg/kg acrolein, and male mice administered 10 mg/kg acrolein were significantly greater than those of the vehicle controls. Female rats administered 10 mg/kg acrolein had significantly lower absolute and relative thymus weights than did the vehicle controls. Female rats administered 25 mg/kg allyl alcohol spent more time in diestrus and less time in metestrus than the vehicle controls. The estrous cycles of female mice dosed with 16 or 32 mg/kg allyl acetate were significantly longer than that of the vehicle controls. Gross lesions related to allyl acetate treatment were observed in the liver, forestomach, and thorax/abdomen of male and female rats in the 100 mg/kg groups. Microscopically, the incidences of forestomach squamous epithelial hyperplasia were significantly increased in male rats administered 12 mg/kg or greater, female rats administered 25 or 50 mg/kg, male mice administered 32 or 62.5 mg/kg, and female mice administered 16, 32, or 62.5 mg/kg. Forestomach necrosis, hemorrhage, and inflammation were present in most rats in the 100 mg/kg groups, and the incidence of hemorrhage in 125 mg/kg male mice was increased; male mice in the 62.5 and 125 mg/kg groups and 125 mg/kg female mice had significantly increased incidences of glandular stomach hemorrhage. Increased incidences of several liver lesions occurred in male or female rats administered 50 or 100 mg/kg, and to a lesser extent in 25 mg/kg rats, 62.5 mg/kg male mice, and 125 mg/kg male and female mice. Bone marrow hyperplasia, hemorrhage or depletion in the mediastinal, mandibular, and mesenteric lymph nodes, hemorrhage and necrosis of the thymus, and hematopoietic cell proliferation of the red pulp were also observed in 100 mg/kg rats. Increased incidences of necrosis in the mandibular and mesenteric lymph nodes, spleen, and thymus were observed in 62.5 and 125 mg/kg mice. Male and female rats administered 6 mg/kg allyl alcohol or greater and male and female mice administered 12 mg/kg allyl alcohol or greater had significantly increased incidences of squamous hyperplasia of the forestomach epithelium. Female rats in the 25 mg/kg group had significantly increased incidences of bile duct hyperplasia and periportal hepatocyte hypertrophy in the liver. Incidences of portal cytoplasmic vacuolization were significantly increased in 50 mg/kg male mice and female mice in the 25 and 50 mg/kg groups. Gross lesions related to acrolein treatment were observed in the forestomach and glandular stomach of male and female rats in the 10 mg/kg groups and 20 mg/kg female mice. Microscopically, the incidences of squamous hyperplasia of the forestomach epithelium were significantly increased in male rats in the 5 and 10 mg/kg groups, female rats administered 2.5 mg/kg or greater, and male and female mice administered 2.5, 5, or 10 mg/kg. Male and female rats in the 10 mg/kg groups and 20 mg/kg male and female mice had significantly increased incidences of glandular stomach hemorrhage. Female mice in the 20 mg/kg group also had significantly increased incidences of glandular stomach inflammation and epithelial necrosis. Allyl acetate was mutagenic in S. typhimurium strains TA100 and TA1535, in the absence of S9 activation. With S9, no mutagenicity was detected in these two strains; negative results were obtained in strains TA97 and TA98, with and without S9. Allyl alcohol was not mutagenic in four strains of S. typhimurium, with or without S9 metabolic activation. Acrolein, tested in a preincubation protocol, was weakly mutagenic in S. typhimurium strain TA100 in the presence of 10% induced rat liver S9. Equivocal results were obtained in strains TA100 and TA1535 with 10% induced hamster liver S9. Negative results were obtained with TA97, TA98, and TA1538 under all test conditions, and acrolein gave negative results in all four S. typhimurium strains tested for mutation induction under a vapor protocol. No induction of micronuclei was noted in bone marrow erythrocytes of male rats administered allyl acetate by gavage three times at 24-hour intervals. No significant increases in micronucleated erythrocytes were noted in bone marrow samples from male rats administered allyl alcohol by intraperitoneal injection for 3 days. A small, but significant increase in the frequency of micronucleated normochromatic erythrocytes was observed in the peripheral blood of female mice administered allyl acetate by gavage for 14 weeks; no increase was observed in male mice. No increases in the frequencies of micronucleated normochromatic erythrocytes were observed in the peripheral blood of male or female mice administered allyl alcohol or acrolein by gavage for 14 weeks. Acrolein induced sister chromatid exchanges in cultured Chinese hamster ovary cells in the absence, but not the presence, of S9; it did not induce chromosomal aberrations, with or without S9. Results of three independent Drosophila melanogaster sex linked recessive lethal tests in which acrolein was administered to adult flies via feeding or injection and to larvae via feeding were negative.

Chemical effects in biological systems--data dictionary (CEBS-DD): a compendium of terms for the capture and integration of biological study design description, conventional phenotypes, and 'omics data.

A critical component in the design of the Chemical Effects in Biological Systems (CEBS) Knowledgebase is a strategy to capture toxicogenomics study protocols and the toxicity endpoint data (clinical pathology and histopathology). A Study is generally an experiment carried out during a period of time for the purpose of obtaining data, and the Study Design Description captures the methods, timing, and organization of the Study. The CEBS Data Dictionary (CEBS-DD) has been designed to define and organize terms in an attempt to standardize nomenclature needed to describe a toxicogenomics Study in a structured yet intuitive format and provide a flexible means to describe a Study as conceptualized by the investigator. The CEBS-DD will organize and annotate information from a variety of sources, thereby facilitating the capture and display of toxicogenomics data in biological context in CEBS, i.e., associating molecular events detected in highly-parallel data with the toxicology/pathology phenotype as observed in the individual Study Subjects and linked to the experimental treatments. The CEBS-DD has been developed with a focus on acute toxicity studies, but with a design that will permit it to be extended to other areas of toxicology and biology with the addition of domain-specific terms. To illustrate the utility of the CEBS-DD, we present an example of integrating data from two proteomics and transcriptomics studies of the response to acute acetaminophen toxicity (A. N. Heinloth et al., 2004, Toxicol. Sci. 80, 193-202).

Systems toxicology and the Chemical Effects in Biological Systems (CEBS) knowledge base.

The National Center for Toxicogenomics is developing the first public toxicogenomics knowledge base that combines molecular expression data sets from transcriptomics, proteomics, metabonomics, and conventional toxicology with metabolic, toxicologcal pathway, and gene regulatory network information relevant to environmental toxicology and human disease. It is called the Chemical Effects in Biological Systems (CEBS) knowledge base and is designed to meet the information needs of "systems toxicology," involving the study of perturbation by chemicals and stressors, monitoring changes in molecular expression and conventional toxicological parameters, and iteratively integrating biological response data to describe the functioning organism. Based upon functional genomics approaches used successfully in analyzing yeast gene expression data sets, relational and descriptive compendia will be assembled for toxicologically important genes, groups of genes, single nucleotide polymorphisms (SNPs), and mutant and knockout phenotypes. CEBS data sets will be fully documented in the experimental protocol and therefore searchable by compound, structure, toxicity end point, pathology and point, gene, gene group, SNP, pathway, and network as a function of dose, time, and the phenotype of the target tissue. A knowledge base is being developed by assimilating toxicological, biological, and chemical information from multiple public domain databases and by progressively refining that information about gene, protein, and metabolite expression for classes of chemicals and their biological effects in various species. By analogy to the GenBank database for genome sequences, researchers will globally query (or BLAST) CEBS using a transcriptome of a tissue of interest (or a list of outliers) to have the knowledge base return information on genes, groups of genes, metabolic and toxicological pathways, and contextually associated phenotypic information for compounds that display similar response profiles. With high-quality data content, CEBS will ultimately become a resource to support hypothesis-driven and discovery research that contributes effectively to drug safety and the improvement of risk assessments for chemicals in the environment. The CEBS development effort will span a decade or more.