N-(hydroxymethyl)acrylamide

Carcinogenicity

Administrative data

Endpoint:

carcinogenicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1983

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented report of a guideline study conducted to GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 451 (Carcinogenicity Studies)

Deviations:

yes

Remarks:

2 dose groups and control no blood examination

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

N-(hydroxymethyl)acrylamide

EC Number:

213-103-2

EC Name:

N-(hydroxymethyl)acrylamide

Cas Number:

924-42-5

Molecular formula:

C4H7NO2

IUPAC Name:

N-(hydroxymethyl)acrylamide

Details on test material:

- Name of test material (as cited in study report): N-METHYLOLACRYLAMIDE
- Physical state: white, microcrystalline powder
- Analytical purity: approximately 98%
- Lot/batch No.: 1-45-000 from Gallard Schlesinger Chemical Manufacturing Corporation (Carle Place, NY).
- Stability under test conditions: No deterioration of the study material was seen over the course of the studies.
- Storage condition of test material: 5°C and 23°C in glass vials for up to 2 weeks during the course of the study.

Test animals

Species:

mouse

Strain:

B6C3F1

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Labo:ratories (Kingston, NY)
- Age at study initiation: 8 weeks
- Weight at study initiation: males 23 g, females 18 g
- Housing: Polycarbonate (Lab Products, Inc.,Rochelle Park, NJ)
- Diet : NIH 07 Rat and Mouse Ration (Zeigler Bros., Inc., Gardners, PA);available ad libitum
- Water : Automatic watering system (Edstrom Industries, Waterford, WI); available ad libitum
- Acclimation period:3 weeks
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 69.8-73.4°F
- Humidity (%): 40-60%
- Air changes (per hr): 15 room air changes/h
- Photoperiod (hrs dark / hrs light): fluorescent light 12 h/d;

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

N-methylolacrylamide in deionized water by gavage; dose vol 5 ml/kg

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Stability studies performed with the gas chromatographic system previously described indicated that N-methylolacrylamide was stable as a bulk chemical when kept for 2 weeks at temperatures up to 25" C. Marked decomposition of the compound was seen at 60" C. The study material was stored at 5" C at the study laboratory.
No deterioration of the study material was seen over the course of the studies. The purity of the chemical at the study laboratory was monitored by gas chromatography and titration with sodium
thiosulfate.
During the 2-year studies, the dose mixtures were analyzed by the study laboratory at approximately 8-week intervals. All 52 mixtures analyzed were formulated to within k 10% of the target concentrations. Results of the periodic referee analyses performed by the analytical chemistry laboratory indicated generally good agreement with the results from the study laboratory

Duration of treatment / exposure:

105 weeks

Frequency of treatment:

5 days a week

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 25, 50 mg/kg in water;
Basis:

No. of animals per sex per dose:

50F+50M per group

Control animals:

yes, concurrent vehicle

Details on study design:

Groups of 50mice of each sex were administered 0, 25, or 50 mg/kg N-methylolacrylamide in deionized water by gavage, 5 days per week for 103 weeks. Mice were shipped to the study laboratory at \ at 5 weeks of age. The animals were quarantined at the study laboratory for 3 weeks. Thereafter, a complete necropsy was performed on five animals of each sex and species to assess their health status. The mice were placed on study at 8 weeks of age. The health of the animals was monitored during the course of the studies according to the protocols of the NTP Sentinel Animal Program. Animals were housed five per cage. Feed and water were available ad libitum. Cages and racks were rotated. All animals were observed two times per day.
Body weights were recorded once per week for the first 13 weeks of the study and once per month thereafter. Mean body weights were calculated for each group. Animals found moribund and those surviving to the end of the studies were humanely killed. A necropsy was performed on all animals, including those found dead, unless they were missing. Some tissues were excessively autolyzed or cannibalized, and thus, the number of animals from which particular organs or tissues were examined microscopically varies and is not necessarily equal to the number of animals that were placed on study.

Positive control:

No

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: two times per day

BODY WEIGHT: Yes
- Time schedule for examinations: Body weights were recorded once per week for the first 13 weeks of the study and once per month thereafter.

Sacrifice and pathology:

GROSS PATHOLOGY: Necropsy performed on all animals
HISTOPATHOLOGY: The following tissues examined histologically for all vehicle control and high dose animals and all animals dying through mo 21: adrenal glands, brain, colon, esophagus, eyes (if grossly abnormal), femur or sternebrae or vertebrae including marrow, gross lesions and tissue masses with regional lymph nodes, kidneys, liver, lungs and mainstem bronchi, mammary gland, mandibular or mesenteric lymph nodes, pancreas, parathyroid glands, peripheral nerve, pituitary gland, prostate/testes or ovaries/uterus, salivary glands, skin, small intestine, spleen, stomach, thymus, thyroid gland, trachea, and urinary bladder.
Tissues examined for low dose animals include adrenal glands, liver, spleen, and testes for male rats; adrenal and pituitary glands for female rats.

Statistics:

Life Table Analyses Mantel-Haenszel method (1959) to obtain an overall P value.
Statistical analyses for a possible dose-related effect on survival used the method of Cox (1972) for testing two groups for equality and
Tarone’s (1975) life table test for a dose related trend.
Analysis of Tumor Incidence: Three statistical methods are used to analyze tumor incidence data: life table tests, logistic regression, and
Fisher exac t/Cochran-Armi tage trend analyses.

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Increased body weight

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

effects observed, treatment-related

Details on results:

CLINICAL SIGNS AND MORTALITY
Chronic inflammation and alveolar epithelial hyperplasia of the lung were observed at increased incidences in mice. Sentinel mice were seropositive for Sendai virus at 18 months.
Deaths of 8 low dose male mice between week 8 and week 32 were considered to be due to a urinary infection; all other early deaths of low dose males and the majority of early deaths of high dose male mice were attributed to the presence of tumors.
No significant differences in survival were observed between any groups of either sex.
BODY WEIGHT AND SURVIVAL:
Mean body weights of dosed mice were as much as 25% greater than those of vehicle controls for females and as much as 13% greater for males.
There were no effects on survival over the two years.
NONNEOPLASTIC AND NEOPLASTIC EFFECTS:
The incidences of adenomas of the Harderian gland were increased in males given either dose of N-methylolacrylamide and in females given the top dose (male: vehicle control: 1/48; low dose: 14/49; high dose: 29/50; female: 5/47; 8/45; 20/48). The incidences of carcinomas of the Harderian gland were not significantly increased. The incidences of hepatocellular adenomas were increased in male and female mice given 50 mg/kg/day (male: 8/50; 4/50; 19/50; female: 3/50; 4/50; 17/49). The incidences of hepatocellular carcinomas were also marginally increased in dosed males. The incidences of alveolar/bronchial adenomas and carcinomas (combined) were increased in male and female mice given 50 mg/kg (males: 5/49; 10/50; 18/50; females: 6/50; 8/50; 13/49).
Ovarian atrophy was observed at increased incidences in female mice receiving N-Methylolacrylamide (3/50; 39/45; 38/47). The incidences of benign granulose cell tumours were also increased in the dosed groups (0/50; 5/45; 5/47). The incidence of adenomas of the pars distalis in high dose female mice was significantly lower than in vehicle controls (13/49; 5/14; 4/43).

Relevance of carcinogenic effects / potential:

The tumours in the mouse were considered to be of questionable relevance to humans because of the unique molecular biology of the murine genome.

Applicant's summary and conclusion

Conclusions:

N-methyoloacrylamide was tumorigenic in male and female mice. In male B6C3F1 mice N-methylolacrylamide increased incidences of neoplasms of the Harderian gland, liver and lung. In female B6C3F1 mice N-methylolacrylamide increased incidences of neoplasms of the Harderian gland, liver, lung and ovary.