Diethylammonium chloride

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

(Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

(no data on detailed clinical observation, sensory reactivity to stimuli, assessment of grip strength, and motor activity)

Data source

Reference

Reference Type:

publication

Title:

Combined repeat dose and reproductive/developmental toxicity screening test of trimethylamine by oral administration in rats.

Author:

Takashima, H., Kuwagata, M., Miyahara, T., Katou, H., Seki, T., Shindou, T., Marumo, H., Horiuchi, S., Inada, H., Saegusa, K., Anjou, T., and Ichihara, S.

Year:

2003

Bibliographic source:

Hatano Research Institute, Food and Drug Safety Center, Japan.

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

yes

Remarks:

(no data on detailed clinical observation, sensory reactivity to stimuli, assessment of grip strength, and motor activity)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: OPPTS 870-3650

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Trimethylamine

EC Number:

200-875-0

EC Name:

Trimethylamine

Cas Number:

75-50-3

Molecular formula:

C3H9N

IUPAC Name:

N,N-dimethylmethanamine

Details on test material:

CAS 75-50-3 (trimethylamine), 30.8% trimethylamine solution, SOURCE: Mitsubishi Gas Chemical Company, Inc. (Niigata; lot # M381012)
The solution contained < 10 ppm of dimethylamine as impurities. Stable for at least 8 days under refrigerated and shielded conditions with a concentration of between 0.08 and 10w/v%.

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

-Age: 9 weeks

Administration / exposure

Route of administration:

oral: gavage

Duration of treatment / exposure:

Males: 42 days; Females: 2 weeks prior to breeding, continuing through breeding (2 weeks), gestation (3 weeks), lactation (4 days), and until the day of necropsy (test day 40 or 54).

Frequency of treatment:

Daily

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

8 mg/kg bw/day (nominal)

Doses / concentrations 2

Dose / conc.:

40 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

200 mg/kg bw/day (nominal)

No. of animals per sex per dose:

13

Control animals:

yes, concurrent vehicle

Examinations

Observations and examinations performed and frequency:

- General condition was observed at least once a day during breeding and at least twice a day before and after dosing over the administration period.

- Body weights for males were determined on days 1, 7, 14, 21, 28, 35, 42 and on the day of necropsy. Body weights were determined for all females on days 1, 7, 14. Females who took time before mating were weighed on days 35 and 42. Females who copulated were weighed on pregnancy days 0, 7, 14 and 20. Females who delivered were weighed on nursing days 0, 4, and on the day of necropsy. Females who copulated but did not deliver were weighed on the equivalent of pregnancy day 25 (day of necropsy).

- Food consumption was measured on days 1, 7, 13, 29, 35 and 41 for males, and on days 1, 7, and 13 for all females. Females with unconfirmed copulation were measured for food consumption on days 29, 35 and 41.

- Urinalysis was conducted on 5 rats/sex/dose level at week 6.

- Hematology and clinical chemistry: Males prior to necropsy and on the  following day after day 42 administration; Females prior to necropsy: females who delivered-following nursing day 4, females who mated but did  not deliver-equivalent of pregnancy day 25, and  females who did not mate- following day 54 of administration.

Sacrifice and pathology:

ORGANS EXAMINED AT NECROPSY (MACROSCOPIC AND MICROSCOPIC):
-Macroscopic: organ weights: testes and epididymides; females, ovaries and uteri were extracted, the pregnancy corpora lutea number of the ovary was counted under the stereoscopic microscope, the implantation number of the uterus was counted, and the implantation rate ((implantation number/pregnancy corpora lutea number) x 100) was calculated.
-Microscopic: 5 animals/sex/control and high dose group- sperm and prostrate ventral lobes of all males and vagina, ovaries and uteri of all females; also testes, epididymides, ovaries found to be abnormal during pathologic examinations were all examined histopathologically.

Statistics:

Mann-Whitney U Test (2-tailed) and Fisher's Exact Test (1-tailed): histopathological examinations,
Dunnett's Multiple Comparison Test (significance level=5%): body weight, food consumption, hematology, clinical chemistry and organ weights

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

-Clinical signs prior to death
200 mg/kg bw/day: The male that died on Day 25 showed salivation, emaciation, abnormal breathing noise and dyspnea from administration day 19, and vulval peripheral fur soiled and loose passage were observed from the day before the death. The male that died on Day 42 showed salivation, emaciation, abnormal breathing noise, dyspnea, a drop in body temperature, faded auricle, tottering and brown soil around the nose were observed from administration day 10, although discontinuously. The female rat that died on pregnancy day 22, was observed with salivation and abnormal breathing noise sporadically from administration day 11.

-Clinical signs in surviving animals:
200 mg/kg bw/day:
Males: salivation 10/13, abnormal breathing noise 3/13, and decreased contact response 1/13;
Females: salivation 10/13, abnormal breathing noise 3/13, and emaciation 1/13.

40 mg/kg/day: no abnormalities

Mortality:

mortality observed, treatment-related

Description (incidence):

-Mortality and time to death: 1 male given 200 mg/kg/day died on day 25, 1 male given 200 mg/kg/day died on day 42 and 1 female died on pregnancy day 22 (administration day 38)

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Males
No significant differences in body weights at 200 mg/kg bw/day; however, body weight gains were decreased when compared to controls. There were no significant differences in body weight or body weight gains in males administered 40 mg/kg bw/day.
Females
No significant differences in body weight or body weight gains.

Food consumption and compound intake (if feeding study):

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

40 mg/kg bw/day: significant increase in urea nitrogen

Urinalysis findings:

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Details on results:

Daily oral administration of trimethylamine by gavage resulted in the death of two males and 1 female administered 200 mg/kg bw/day. Abnormal breathing noise, salivation immediately after the administration, ulcers and inflammatory changes in the stomach and intestinal tracts, squamous hyperplasia and edema in submucosa were observed in both males and females in the 200 mg/kg bw/day group. An inhibitory tendency in body weight increase, decrease in food consumption, total protein concentration and albumin concentration were also observed in the males in the same group.
There was no effect of trimethylamine administration on body weights and food consumption of the females and on organ weights, urine examination and hematological examination results in the males and females. Therefore it was inferred that the general toxicological NOAEL (No Observed Adverse Effect Level) is 40 mg/kg bw/day.

Effect levels

Key result

Dose descriptor:

NOAEL

Effect level:

40 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Treatment-related and adverse effects (clinical signs and mortality) observed at 200 mg/kg bw/day

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

The NOAEL for systemic toxicity was considered to be 40 mg/kg bw/day based on abnormal breathing noise and salivation immediately after the administration, ulcers and inflammatory changes in the stomach and intestinal tracts, squamous hyperplasia and edema in submucosa, which were observed in both males and females in the 200 mg/kg bw/day group. These local effects (ulcers, inflammation) at sites of contact (stomach, intestines) were considered to be due to corrosive properties of substance.