heptan-2-yl [(5-chloroquinolin-8-yl)oxy]acetate

Toxicity to reproduction

Administrative data

Endpoint:

two-generation reproductive toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 September 1989 - 5 October 1990

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)

Version / remarks:

1983 (current guideline adopted 2001)

Deviations:

yes

Remarks:

(does not meet current guideline specification)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPP 83-4 (Reproduction and Fertility Effects)

Version / remarks:

1982 (current guideline adopted 1998)

Deviations:

yes

Remarks:

(does not meet current guideline specification)

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

heptan-2-yl [(5-chloroquinolin-8-yl)oxy]acetate

EC Number:

619-447-3

Cas Number:

99607-70-2

Molecular formula:

C18H22ClNO3

IUPAC Name:

heptan-2-yl [(5-chloroquinolin-8-yl)oxy]acetate

Details on test material:

- Name of test material (as cited in study report): CGA185072 technical
- Analytical purity: 91.6 %

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source of animals: Charles River, 8741 Sulzfeld, Germany
- Strain: Spraque-Dawley rats, strain Crl:CD (SD)BR
- Age at study initiation: P generation - approx. 6 weeks old
- Weight at study initiation: P generation - males 162-226 g, females 134-181 g
- Housing: individual in solid floor macrolone cages with stainless steel lids except during mating (one male with one female) and during lactation (one female with litter). Autoclaved sawdust bedding.
- Diet: powdered Ssniff R 10 ad libitum
- Source of feed: Ssniff Spezialdiäten GmbH, 4770 Soest, Germany
- Water: tap water in plastic bottles ad libitum
- Acclimation period: P generation 18 days

ENVIRONMENTAL CONDITIONS
- Temperature: 19-25°C
- Humidity: 30-70%
- Photoperiod: 12 hrs dark / 12 hrs light

Administration / exposure

Route of administration:

oral: feed

Vehicle:

other: diet

Details on exposure:

DIET PREPARATION
- The test substance was milled to a standardised particle size and admixed to the powdered diet. Fresh preparations were made monthly

Details on mating procedure:

One male was housed with one female from the same group for up to three weeks. After 2 weeks, females with no evidence of mating were paired with a proven male from the same group. Mating was confirmed by the presence of sperm in a vaginal smear or a vaginal plug and designated day 0 of gestation. After successful mating, females and males were caged individually. Sibling pairing was avoided.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

All batches of test diet made were analysed for achieved concentration and homogeneity. Stability was confirmed for the period of use and storage conditions. Satisfactory results were obtained. Analysis was by HPLC.

Duration of treatment / exposure:

From the start of the P generation through to necropsy of individual animals - F1 and F2a.

Frequency of treatment:

Continuous

Details on study schedule:

- Pre-mating period P Generation: 100 days
- Selection of F parents from F1 generation at 21 days of age
- F1 parental animals not mated until 100 days after weaning

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 ppm

Remarks:

Negative control

Doses / concentrations 2

Dose / conc.:

50 ppm

Doses / concentrations 3

Dose / conc.:

500 ppm

Doses / concentrations 4

Dose / conc.:

5 000 ppm

Doses / concentrations 5

Dose / conc.:

10 000 ppm

No. of animals per sex per dose:

25

Control animals:

yes, plain diet

Details on study design:

- Dose selection rationale: on basis of preliminary study
- Rationale for animal assignment: P generation by stratified randomisation based on body weight and the use randomisation tables; F1 generation selected by stratified use of randomly drawn cards

Positive control:

No

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: once weekly for males and females during the pre-mating and mating periods; for females on days 0, 7, 14 and 20 post coitum and days 1, 4, 7, 14 and 21 post partum

FOOD CONSUMPTION:
- Time schedule for examinations: twice weekly for males and females during the pre-mating period; for females on days 0-3, 3-7, 7-10, 10-14, 14-20 post coitum and days 1-4, 4-7, 7-10, 10-12, 14-15, 15-16, 16-17, 17-18, 18-19, 19-20, 20-21 post partum. Food consumption was calculated as mean daily food consumption per measuring period
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

OTHER:
- Date of mating
- Date of parturition
- Duration of gestation
- Abnormalities of nesting or nursing behaviour

Oestrous cyclicity (parental animals):

Not recorded

Sperm parameters (parental animals):

Not recorded

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes to 8 pups (4 males and 4 females where possible)

PARAMETERS EXAMINED
- F1 and F2 offspring: number and sex of pups, live births, postnatal mortality, clinical condition, body weight, pinna unfolding, tooth eruption, eye opening, pupillary reflex and auditory response

GROSS EXAMINATION OF DEAD PUPS:
- yes, for external and visceral abnormalities

Postmortem examinations (parental animals):

Parental males were necropsied after mating, females after weaning. Successfully mated females which failed to produce a litter were necropsied on day 26 post coitum. All parental animals were examined for gross pathological changes. Uteri were immersed in 10% ammonium sulfide to reveal evidence of implantation. The number of implantations was recorded.
The following tissues were sampled and fixed from all F0 and F1 adult animals: bladder, cervix, coagulating gland, epididymides, kidneys, liver, ovaries, pituitary, prostate, seminal vesicles, testes, uterus, vagina and macroscopically altered organs. Histopathology was conducted in controls and top dose group animals. Epididymides, kidneys, liver and testes were weighed before fixation. In addition, the kidneys of group 4 animals were examined histologically.

Postmortem examinations (offspring):

Non-selected pups from F1 and F2 litters were necropsied after weaning.

Statistics:

Statistical analyses used the SAS software package release 6.03.
Analysis of variance with one factor treatment followed by the Student-Newman-Keuls test for multiple group comparisons: body weight, body weight gain, litter weight, organ weights, food consumption.
Analysis of variance with one factor treatment based on taking the ranks of the variables and followed by the Student-Newman-Keuls test for multiple group comparisons: mating performance, duration of gestation, mean pup weight, pup number, live birth index, viability indices, weaning index, pinna unfolding, hair growth, incisor eruption, eye opening.

Reproductive indices:

For both generations the parental reproductive performance was assessed and the following calculated: mating performance, insemination index, fecundity index, fertility index, gestation index

Offspring viability indices:

Live birth index, pup viability index, weaning index and sex ratio

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Five P females with fur staining

Mortality:

no mortality observed

Description (incidence):

No effects in P animals

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

The males and females of the P and F1 generations given 10000 ppm had slightly lower body weights during the premating period.

Food consumption and compound intake (if feeding study):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Effect levels (P0)

1

Key result

Dose descriptor:

NOAEL

Effect level:

10 000 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

reproductive performance

Remarks on result:

not determinable due to absence of adverse toxic effects

Remarks:

highest dose tested equivalent to 830 mg/kg bw/day

2

Key result

Dose descriptor:

NOAEL

Remarks:

toxicity

Effect level:

5 000 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

Remarks on result:

other: Equivalent to 420 mg/kg bw/day.

Results: P1 (second parental generation)

General toxicity (P1)

Clinical signs:

no effects observed

Mortality:

mortality observed, treatment-related

Description (incidence):

Four P1 males given 10000 ppm were found dead

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

The males and females of the P1 generation given 10000 ppm had slightly lower body weights during the premating period.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Slightly lower food consumption in P1 generation males and females.

Food efficiency:

not examined

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Changes in the kidneys and urinary bladder in particular were considered to be related to treatment with 10000 ppm in P1 males and females. Groups given 50, 500 or 5000 ppm were unaffected.

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Changes in the kidneys and urinary bladder were considered to be related to treatment with 10000 ppm in P1 males and females. There were a variety of inflammatory changes, namely moderate to marked subacute to chronic interstitial pyelonephritis associated with changes such as hyaline casts, tubular and pelvis dilatation associated with parenchymal atrophy, pelvis lithiasis and signs of hyperplastic response such as proliferation and metaplasia of the urothelium. Groups given 50, 500 or 5000 ppm were unaffected.

Reproductive function / performance (P1)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Effect levels (P1)

1

Key result

Dose descriptor:

NOAEL

Effect level:

10 000 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

reproductive performance

Remarks on result:

not determinable due to absence of adverse toxic effects

2

Key result

Dose descriptor:

NOAEL

Effect level:

5 000 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

gross pathology

histopathology: non-neoplastic

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Mortality / viability:

mortality observed, non-treatment-related

Description (incidence and severity):

During the lactation period, pup losses were observed in all groups and no treatment-related effect was detected.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

The mean pup weight of the F1a pups was significantly reduced at weaning on day 21 post partum.

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

no effects observed

Anogenital distance (AGD):

not examined

Nipple retention in male pups:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Macroscopic examination revealed a high incidence of changes in the kidneys, particularly dilatation of the renal pelvis, in the F1a pups; groups treated at 50, 500 and 5000 ppm remained unaffected.

Histopathological findings:

not examined

Other effects:

no effects observed

Description (incidence and severity):

Treatment with cloquintocet-mexyl had no effect on the nature or incidence of malformations observed in the F1a pups.

Developmental neurotoxicity (F1)

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

There were no treatment-related effects on the physical development (incisor eruption, pinna unfolding, eye opening) of the F1a pups or on the outcome of the functional tests (pupillary reflex, auditory response) on either generation.

Developmental immunotoxicity (F1)

Developmental immunotoxicity:

not examined

Effect levels (F1)

1

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

10 000 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

viability

sexual maturation

mortality

other: Nature and incidence of malformations

2

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

5 000 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

gross pathology

histopathology: non-neoplastic

Target system / organ toxicity (F1)

Key result

Critical effects observed:

no

Results: F2 generation

General toxicity (F2)

Clinical signs:

no effects observed

Mortality / viability:

mortality observed, non-treatment-related

Description (incidence and severity):

During the lactation period, pup losses were observed in all groups and no treatment-related effect was detected.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

The mean pup weight of the F2a pups was significantly reduced at weaning on day 21 post partum.

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Anogenital distance (AGD):

not examined

Nipple retention in male pups:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

A low incidence of F2a pups had dilatation of the renal pelvis not clearly treatment-related.

Other effects:

no effects observed

Description (incidence and severity):

Treatment with cloquintocet-mexyl had no effect on the nature or incidence of malformations observed in the F2a pups.

Developmental neurotoxicity (F2)

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

There were no treatment-related effects on the physical development (incisor eruption, pinna unfolding, eye opening) of the F2a pups or on the outcome of the functional tests (pupillary reflex, auditory response) on either generation.

Developmental immunotoxicity (F2)

Developmental immunotoxicity:

not examined

Effect levels (F2)

Key result

Dose descriptor:

NOAEL

Generation:

F2a

Effect level:

5 000 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

Target system / organ toxicity (F2)

Key result

Critical effects observed:

no

Overall reproductive toxicity

Key result

Reproductive effects observed:

no

Any other information on results incl. tables

Table 1 Test Substance Intake During The Pre-Mating Period (corrected means – mg/kg/day)

 

Males	Dietary concentration (ppm)				Females	Dietary concentration (ppm)
P Generation	50	500	5000	10000	P Generation	50	500	5000	10000
Week 1	5.2	51.2	555.4	1066.9	Week 1	5.1	49.7	548.8	1086.0
Week 14	2.8	28.0	277.9	565.9	Week 14	3.7	35.9	369.9	732.4
Mean intake	3.5	35.3	370.7	721.6	Mean intake	4.2	40.7	422.8	846.9
Overall mean intake for males and females	3.9	38.0	396.8	784.3
F1 Generation					F1 Generation
Week 1	6.2	66.6	627.1	1212.1	Week 1	6.6	69.1	673.0	1274.9
Week 14	2.9	30.7	300.9	613.3	Week 14	3.7	38.4	372.2	735.4
Mean intake	4.0	41.1	408.7	819.5	Mean intake	4.6	48.3	487.3	945.6
Overall mean intake for males and females	4.3	44.7	448.0	882.6
Overall mean intake for males and females P + F1 generations	4.1	41	422	833

 

Table 2 Group Mean Pup Body Weight (g)

 

F1a pup Weight (g)	Dietary concentration (ppm)					F2a pup Weight (g)	Dietary concentration (ppm)
	0	50	500	5000	10000		0	50	500	5000	10000
Day 1	6.1	5.9	6.1	6.1	6.2	Day 1	6.2	6.0	5.9	6.1	6.3
Day 4	7.5	7.1	7.3	7.6	7.6	Day 4	8.0	7.6	7.3	7.6	7.9
Day 7	11.4	10.3	10.8	11.4	10.9	Day 7	11.6	11.4	10.3	10.6	11.2
Day 14	24.5	21.6	22.9	25.2	21.8	Day 14	24.3	24.6	22.9	24.7	23.8
Day 21	41.0	36.6	38.3	39.6	34.9*	Day 21	41.8	41.0	40.3	40.0	37.7*

 P<0.05 * statistically significant difference from control

Table 3 Incidence of pups with renal pelvic dilatation

 

F1a pups	Dietary concentration (ppm)					F2a pups	Dietary concentration (ppm)
	0	50	500	5000	10000		0	50	500	5000	10000
No. Examined	228	253	232	237	206	No. Examined	197	217	185	231	213
Unilateral	1	0	2	0	10	Unilateral	1	1	1	2	1
Bilateral	1	1	3	0	20	Bilateral	0	0	1	3	2

 

Applicant's summary and conclusion

Conclusions:

Administration of cloquintocet-mexyl to rats at up to 10000 ppm in the diet over two generations resulted in no effects on the fertility or reproductive performance in either generation and no effect on the number and viability of the pups born.

Executive summary:

The reproductive toxicity of cloquintocet-mexyl to rats was studied under GLP in a two-generation study conducted to OECD TG 416. Groups of 25 male and 25 female Sprague-Dawley rats were given the substance in the diet at nominal concentrations of 0, 50, 500, 5000 and 10000 ppm continuously from the start of treatment until necropsy.

After a pre-mating period, the P0 parental animals were mated and allowed to litter and to rear the P1 pups to weaning. After a 100 day post weaning maturation period the selected P1 parental animals were mated and allowed to litter and to rear the F1 pups to weaning.

At 10000 ppm, effects in the P0 and P1 parental animals included reduced body weight and food consumption, the death of four P1 males and histological changes in the kidney and urinary bladder of the P1 animals. For pups, mean body weight was significantly reduced on day 21 for both P1 and F1 pups and the incidence of renal pelvic dilatation was increased in P1 pups. There were no adverse effects of 50, 500 or 5000 ppm.

There was no effect on fertility or general reproductive performance in either of the two generations at any dietary concentration of cloquintocet-mexyl in this study. There was also no effect on the nature or incidence of malformations observed in the pups of the P1 and F1 generations.