Tris(2-hydroxyethyl)ammonium acetate

Toxicity to reproduction: other studies

Administrative data

Endpoint:

toxicity to reproduction: other studies

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006-11-06 to 2008-01-10

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study is the result of a structural analogue substance used as read-across substance. Study is conducted according to Guidelines in a GLP certified laboratory.

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 415 (One-Generation Reproduction Toxicity Study)

Deviations:

no

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

in vivo

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

427-360-5

EC Name:

-

IUPAC Name:

427-360-5

Details on test material:

Description: Light Yellow Solid
Stability of test compound: Stable

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

- Males: The test item was administered during a 70-day pre-pairing period, during the pairing period and until necropsy
- Females: The test item was administered during a 14-day pre-pairing period and also during the pairing, gestation and lactation periods until necropsy

Frequency of treatment:

Once daily

Duration of test:

Total duration of the test was 120 days

Doses / concentrations

Remarks:

Doses / Concentrations:
0 (control), 100, 300 and 1000 mg/kg bw/day
Basis:
nominal in water

No. of animals per sex per dose:

24 animals per sex per dose

Control animals:

yes, concurrent vehicle

Results and discussion

Effect levels

Dose descriptor:

NOEL

Effect level:

300 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Observed effects

In females, the post implantation loss, number of dead pups were increased at 1000 mg/kg bw/day. In males food consumption and body weight gain were reduced during the first quarter of the pre-pairing period in the highest dose group. Furthermore, the liver body weight ratio was increased in males following treatment with the test item at 1000 mg/kg bw/day.

Any other information on results incl. tables

There were no mortalities or clinical signs observed in parental animals from any group. Males treated with 1000 mg/kg bw/day had significantly decreased food consumption during the first 15 days of the pre-pairing period. Mean body weight and mean body weight gain were also reduced during the first 20 days of the pre-pairing period. Food consumption, body weight and body weight gain of females was not affected by treatment with the test item.

 

For males at 1000 mg/kg bw/day, the mean liver body weight ratio was statistically significantly increased and was considered to be test item related. An increase in post-implantation loss was seen in females treated with 1000 mg/kg bw/day and this was considered to be possibly test item related.

 

There was no increase in mortality or clinical signs observed in the F1 pups following treatment with the test item. Mean pup weight was not affected by treatment. Additionally, during the macroscopic examination of pups no abnormal findings that were considered to be related to treatment with the test item were noted.

Table 1: Summary of food consumption of males

Days	Group 1 (0 mg/kg bw/day)		Group 2 (100 mg/kg bw/day)		Group 3 (300 mg/kg bw/day)		Group 4 (1000 mg/kg bw/day)
	Food consumption (g)	% of control	Food consumption (g)	% of control	Food consumption (g)	% of control	Food consumption (g)	% of control
Pre-pairing period
1 - 8	23.6 ± 1.5	-	23.4± 1.3	-0.8	22.9 ± 1.3	-3.0	22.5 ± 1.1**	-4.7
8 - 15	24.4 ± 1.7	-	24.1 ± 1.6	-1.2	23.6 ± 1.9	-0.8	22.8 ± 1.4**	-0.8
15 - 22	24.4 ± 1.9	-	24.2 ± 2.0	-0.8	23.7 ± 1.8	-2.9	23.7 ± 1.4	-2.9
22 - 29	24.2 ± 2.0	-	24.0 ± 1.9	-0.8	23.7 ± 1.8	-2.1	23.7 ± 1.5	-2.1
29 - 36	23.9 ± 2.1	-	24.2 ± 1.7	-1.3	23.7 ± 1.9	-0.8	23.7 ± 1.3	-0.8
36 - 43	23.8 ± 1.6	-	24.0 ± 1.7	-0.8	23.6 ± 2.0	-0.8	23.7 ± 1.3	-0.4
43 - 50	23.6 ± 1.9	-	23.4 ± 1.7	-0.8	23.3 ± 1.7	-1.3	23.6 ± 1.3	+0.0
50 - 57	24.5 ± 2.0	-	24.6 ± 2.0	-0.4	24.4 ± 2.1	-0.4	25.1 ± 1.4	+2.4
57 - 64	24.2 ± 1.9	-	24.3 ± 1.7	+0.4	24.2 ± 1.9	+0.0	24.3 ± 1.3	+0.4
64 - 70	24.7 ± 2.0	-	24.6 ± 1.8	-0.4	24.5 ± 1.9	-0.8	24.8 ± 1.5	+0.4
After pairing period
1 - 8	23.9 ± 3.3	-	24.3 ± 1.7	+1.7	24.6 ± 2.0	+2.9	24.4 ± 1.4	+2.1
8 - 15	24.2 ± 2.0	-	23.5 ± 1.7	-2.9	24.2 ± 1.9	+0.0	23.7 ± 1.4	-2.1
15 - 19	24.1 ± 2.4	-	24.0 ± 1.8	-0.4	24.8 ± 2.5	+2.9	24.9 ± 1.5	+3.3

* p<0.05, ** p<0.01

 

Table 2: Summary of food consumption of females 

Days	Group 1 (0 mg/kg bw/day)		Group 2 (100 mg/kg bw/day)		Group 3 (300 mg/kg bw/day)		Group 4 (1000 mg/kg bw/day)
	Food consumption (g)	% of control	Food consumption (g)	% of control	Food consumption (g)	% of control	Food consumption (g)	% of control
Pre-pairing period
1 - 8	18.0± 1.2	-	17.5± 1.4	-2.8	17.2± 1.2	-4.4	17.2± 1.2	-4.4
8 - 14	18.7± 1.4	-	18.3± 1.7	-2.1	17.8± 1.3	-4.8	18.1± 1.4	-4.4
Gestation period
1 - 7	22.2± 2.7	-	22.2± 2.0	+0.0	22.4± 2.1	+0.9	22.5± 1.9	+1.4
7 - 14	24.1± 2.6	-	24.0± 2.1	-0.5	24.1± 2.1	+0.0	24.5± 2.2	+1.7
14 - 21	25.7±2.4	-	25.0± 2.6	-2.7	25.9± 1.9	+0.8	26.0± 2.1	+1.1
Lactation period
1 - 7	36.0± 3.9	-	36.5± 6.0	+1.4	36.4± 3.8	+1.1	36.6± 4.6	+1.7
7 - 14	55.6± 4.3	-	54.7± 8.7	-1.6	57.2± 3.9	+2.9	54.4± 5.0	-2.2

 

Table 3: Summary of body weights (g) and body weight gain (%) of males 

Days	Group 1 (0 mg/kg bw/day)		Group 2 (100 mg/kg bw/day)		Group 3 (300 mg/kg bw/day)		Group 4 (1000 mg/kg bw/day)
	Body weight (g)	Body weight gain (%)	Body weight (g)	Body weight gain (%)	Body weight (g)	Body weight gain (%)	Body weight (g)	Body weight gain (%)
Pre-pairing period
1	203 ± 9.4	0	203± 8.1	0	201 ± 8.5	0	202± 8.1	0
8	243 ± 11.9	19	241 ± 10.2	19	237 ± 14.9	18	236 ± 11.2	17*
15	276 ± 15.3	36	272 ± 14.2	34	267 ± 21.2	33	262 ± 16.1*	30**
22	303 ± 18.9	49	300 ± 19.0	48	296 ± 25.8	47	289 ± 18.8	43
29	325 ± 21.1	60	322 ± 22.0	59	319 ± 28.6	59	311 ± 21.5	54
36	342 ± 23.3	68	339 ± 23.8	67	326 ± 32.0	67	327 ± 23.1	62
43	357 ± 25.0	76	354 ± 26.0	75	353 ± 36.2	76	345 ± 23.8	71
50	369 ± 25.9	82	366 ± 28.1	81	365 ± 36.8	82	356 ± 25.5	76
57	383 ± 27.9	88	380 ± 29.9	88	381 ± 38.0	89	369 ± 25.5	83
64	393 ± 29.8	94	389 ± 30.4	92	391 ± 39.6	95	378 ± 27.9	87
70	401 ± 30.6	97	396 ± 31.4	96	399 ± 40.8	99	384 ± 28.7	90
Pairing period
1	398 ± 31.4	0	392 ± 31.1	0	395 ± 42.7	0	379 ± 28.8	0
8	406 ± 30.5	2	401 ± 31.2	2	407 ± 40.4	3*	390 ± 28.0	3*
15	414 ± 31.9	4	409 ± 31.7	4	418 ± 41.5	6**	399 ± 31.0	5
18	418 ± 31.7	5	414 ± 32.2	6	422 ± 41.7	7**	403 ± 30.7	6
After pairing period
1	419 ± 32.1	0	415 ± 32.3	0	423 ± 41.8	0	403 ± 29.9	0
8	422 ± 33.1	1	419 ± 33.2	1	428 ± 42.9	1	402 ± 30.1	0
15	428 ± 33.6	2	427 ± 34.2	3	436 ± 43.5	3	411 ± 30.1	2
19	432 ± 36.1	3	430 ± 35.3	4	440 ± 44.8	4	412 ± 29.5	2

* p<0.05, ** p<0.01

 

Table 4: Summary of body weights (g) and body weight gain (%) of females 

Days	Group 1 (0 mg/kg bw/day)		Group 2 (100 mg/kg bw/day)		Group 3 (300 mg/kg bw/day)		Group 4 (1000 mg/kg bw/day)
	Body weight (g)	Body weight gain (%)	Body weight (g)	Body weight gain (%)	Body weight (g)	Body weight gain (%)	Body weight (g)	Body weight gain (%)
Pre-pairing period
1	157 ± 9.4	0	159± 6.1	0	157 ± 6.1	0	157 ± 8.7	0
8	176 ± 10.1	12	175 ± 8.1	11	174 ± 8.3	11	173 ± 9.4	10
14	188 ± 12.7	20	186 ± 7.9	18	184 ± 9.1	17	186 ± 9.8	18
Pairing period
1	193 ± 13.4	0	193 ± 8.1	0	192 ± 8.1	0	191 ± 8.1	0
8	208	17	205 ± 9.4	10	-	-	-	-
15	-	-	218	13	-	-	-	-
18	-	-	229	19	-	-	-	-
Gestation period
1	195 ± 12.2	0	197 ± 10.4	0	192 ± 10.9	0	193 ± 8.9	0
8	230 ± 15.1	18	231 ± 13.5	17	229 ± 13.5	20	229 ± 11.8	18
15	264 ± 20.1	36	264 ± 15.9	34	262 ± 15.8	37	264 ± 15.9	37
19	308 ± 23.5	58	307 ± 21.3	56	309 ± 18.2	62	309 ± 20.3	60
Lactation period
1	240 ± 19.7	0	237 ± 14.3	0	241 ± 15.9	0	244 ± 13.8	0
8	268 ± 19.2	12	269 ± 19.0	13	269 ± 13.4	12	270 ± 13.7	11
15	288 ± 19.8	20	291 ± 19.1	23	290 ± 14.0	21	291 ± 17.8	19
21	280 ± 19.1	17	286 ± 16.8	21*	288 ± 12.0	20	291 ± 15.8*	19

 

Table 5: Breeding data per group 

	Group 1 (0 mg/kg bw/day)	Group 2 (100 mg/kg bw/day)	Group 3 (300 mg/kg bw/day)	Group 4 (1000 mg/kg bw/day)
Litters	23	24	23	24
Duration of gestation (days)	21.5 ± 0.51	21.5 ± 0.51	21.3 ± 0.49	21.5 ± 0.51
Implantations	13.0 ± 2.04	12.9 ± 2.97	13.2 ± 1.91	13.3 ± 1.78
Post implantation loss	0.5 ± 0.95	0.7 ± 0.86	0.7 ± 0.88	1.8 ± 1.86*
Dead pups at first litter check Litters affected (#) Total number of pups	1 1	0 0	1 1	2 8
Living pups at first litter check % of males/females Mean ± SD	53/47 12.5 ± 2.02	47/53 12.2 ± 2.79	45/55* 12.6 ± 1.80	45/55* 11.5 ± 2.55
Postnatal loss days 0-4 p.p. as % of living pups Litters affected (#) Total number of pups	1.0 3 3	0.3 1 1	2.4 5 7	1.5 3 4
Breeding loss days 5-21 p.p. as % of living pups Litters affected (#) Total number of pups	0.0 0 0	0.5 1 1	0.0 0 0	0.0 0 0
Birth index	96.0	94.5	95.1	86.5**
Viability index	99.0	99.7	97.6	98.5
Weaning index	100.0	99.5	100.0	100.0

Applicant's summary and conclusion

Conclusions:

The NOEL for parental animals and F1 pups was established at 300 mg/kg bw/day, based on reductions in food consumption, body weight gain and liver body weight ratio in males, and increased post-implantation loss in females.

Executive summary:

The potential of Read Across substance 2 (RA2) to induce reproductive toxicity was investigated in a one-generation reproduction toxicity study. RA2 was administered to groups of Wistar rats (24/sex/dose) at the following doses: 0, 100, 300 and 1000 mg/kg bw/day. The test item was administered once daily to males for a 70 day pre-pairing period, during the pairing period and until the last litter had reached day 4 post partum. Females received the test item during a 14 day pre-pairing period and also during the pairing, gestation and lactation periods.

 

Parental rats were regularly monitored for mortality and clinical signs twice a day. Body weight was recorded daily from the start of treatment until necropsy. Food consumption was recorded weekly. All parental animals were subjected to gross necropsy, with particular attention to the organs of the reproductive system. Histopathological observations were carried out on the following organs for all high dose and control parental animals: pituitary glands, adrenals, uterus, oviducts, cervix, ovaries, testes with epididymides, prostate, seminal vesicles with coagulating glands, vagina, target organs. Histopathology was also performed on the reproductive organs of all infertile animals and on all gross lesions from all animals.

 

Reproductive and litter parameters assessed included: pregnant females during the first/second pairing period, number of females delivering pups, not mated/not pregnant, number of females rearing pups to weaning, duration of gestation, implantation rate, post-implantation loss, litter size, postnatal loss, breeding loss, abnormal findings at birth/during lactation/at macroscopic examination, pup weights after birth and sex ratios.

 

There were no mortalities or clinical signs observed in parental animals from any group. Males treated with 1000 mg/kg bw/day had significantly decreased food consumption during the first 15 days of the pre-pairing period. Mean body weight and mean body weight gain were also reduced during the first 20 days of the pre-pairing period. Food consumption, body weight and body weight gain of females was not affected by treatment with the test item.  

For males at 1000 mg/kg bw/day, the mean liver body weight ratio was statistically significantly increased and was considered to be test item related. An increase in post-implantation loss was seen in females treated with 1000 mg/kg bw/day and this was considered to be possibly test item related.

 

There was no increase in mortality or clinical signs observed in the F1 pups following treatment with the test item. Mean pup weight was not affected by treatment. Additionally, during the macroscopic examination of pups no abnormal findings that were considered to be related to treatment with the test item were noted.

The NOEL for parental animals and F1 pups was therefore established at 300 mg/kg bw/day.