1,4-Methanonaphthalen-5(1H)-one, 9-(dichloromethylene)-2,3,4,6,7,8-hexahydro-, oxime, (5E)-

Toxicity to reproduction

Administrative data

Endpoint:

two-generation reproductive toxicity

Remarks:

The two-generation reproductive toxicity study was conducted solely to comply with non-EU national registration requirement, and has been provided here in accordance with REACH, Article 22(1)e.

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 09 May 2013 to 21 January 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.3800 (Reproduction and Fertility Effects)

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: JMAFF, 12 - NohSan No. 8147 (2000)

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

N-[(3E)-11-(dichloromethylidene)tricyclo[6.2.1.0²,⁷]undec-2(7)-en-3-ylidene]hydroxylamine

EC Number:

700-700-2

Cas Number:

1369492-55-6

Molecular formula:

C12H13Cl2NO

IUPAC Name:

N-[(3E)-11-(dichloromethylidene)tricyclo[6.2.1.0²,⁷]undec-2(7)-en-3-ylidene]hydroxylamine

Test animals

Species:

rat

Strain:

Wistar

Details on species / strain selection:

The rat is a suitable rodent species, acceptable to regulatory authorities and for which extensive background data are available. The Han Wistar rat is commonly used in reproduction studies because of the good fertility and fecundity of the strain.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (UK) Limited, Margate, Kent, CT9 4LT, England.
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: (P) males 5 to 6 weeks and females 4 to 5 weeks; (F1) 20 Day
- Weight at study initiation: (P) Males: 140 - 209 g; Females: 98 - 136 g
- Fasting period before study: No
- Housing: The P generation animals and selected F1 generation animals were housed in groups of four, by sex, until pairing and for males post-pairing.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 °C to 23 °C
- Humidity (%): 24 % to 81 %
- Air changes (per hr): not specified
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

1 % aqueous carboxymethylcellulose

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
The test item was formulated for dosing as a suspension in the vehicle, 1 % (w/v) aqueous carboxymethylcellulose at approximately weekly intervals (within the known stability) for
each group.
For use in the first week of dosing, a stock suspension was prepared using the highest concentration (100 mg/mL, Group 4 dose level) and the low and intermediate dose groups were prepared by dilution of this stock; however, the results of analysis of the low and intermediate dose levels were not optimal. After consultation with the Sponsor dosing commenced using the original formulation for Groups 1 and 4 and a re-preparation of Groups 2 and 3 was performed (used from the second day of dosing) by mixing the required amount of test item with the appropriate quantity of vehicle; this method was used for the remainder
of the study.
A weighed quantity of test item was mixed using a pestle with a small quantity of the vehicle in a mortar to form a smooth paste. Via further progressive additions of vehicle and mixing, this was then taken up to near final volume or weight. The mortar was rinsed with vehicle and the rinsings were added to the formulation. Once at final volume/weight (using a density correction of 1.023 for the 100 mg/mL (Group 4)), the formulation was mixed using a laboratory homogeniser, stirred using a magnetic stirring bar and then dispensed into aliquots for dosing.
Formulations were stored frozen (at approximately -18 °C) once made or, if to be used the following day, were stored at room temperature in the dark. Frozen formulations were removed from the freezer and stored overnight at room temperature to defrost. On several occasions throughout the study the bottles cracked and additional formulations had to be prepared. On the day of use, formulations were stirred for at least 30 minutes before and during the dosing procedure.

VEHICLE
1 % (w/v) aqueous carboxymethylcellulose

Details on mating procedure:

- M/F ratio per cage: For pairing, one male and one female from the same group (avoiding sibling mating for F1 animals)
- Length of cohabitation: for up to 14 days
- Proof of pregnancy: vaginal plug / sperm in vaginal smear
- Further matings after two unsuccessful attempts: no
- After successful mating each pregnant female was caged: individually

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Homogeneity and stability of test item formulations at concentrations between 0.1 mg/mL and 100 mg/mL in vehicle, spanning those used on this study (5 mg/mL to 100 mg/mL), were examined prior to the start of this study and they were shown to be stable for at least one day at room temperature in the dark and up to eight days when stored frozen (approximately -18 ºC).
Samples were taken from each formulation. The samples from all formulations prepared for use during the first two weeks of treatment (five occasions) were analysed. For the remainder of the first two months of the study, formulation analysis was performed on samples taken from formulations every two weeks; and then once every two months thereafter. All remaining samples were stored frozen (approximately -18 ºC) and will be discarded following the issue of the final report.
Samples from formulations containing the test item were analysed using a previously validated method BFI009LC to determine their homogeneity and achieved concentrations. Samples from the Control formulations were analysed for the absence of the test item.

Duration of treatment / exposure:

All animals were dosed for at least 10 weeks before pairing and then until the day prior to necropsy. Males were dosed before, during and after pairing, and females were dosed before and during pairing, and during gestation and lactation until Day 20 of lactation. Animals that were in mid-parturition at the time of dosing were not dosed on that day. The selected F1 generation was dosed from Day 21 of age.

Frequency of treatment:

once daily

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

50 mg/kg bw/day (nominal)

Doses / concentrations 2

Dose / conc.:

250 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

1 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

24 males and 24 females per dose level and for each generation.

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale:
The dose levels were selected on the basis of results from a preliminary study performed in the same laboratory. The test item was administered once daily, via oral gavage, to groups of five male and five female Han Wistar rats at dose levels of 0, 100, 300 or 1000 mg/kg/day for 28 days.
On the basis of this study it was anticipated that there would be minor pathology findings in males and females at 1000 mg/kg/day, which represents the limit dose for studies of this type. Doses of 50 and 250 mg/kg/day were included to determine the dose response of any effects seen at the high dose.

- Rationale for animal assignment:
Allocation to groups was performed using a stratified randomisation procedure based on individual body weights recorded on arrival. The cages were positioned in the battery using a randomised cage allocation procedure. Each animal was uniquely identified by a subcutaneously implanted micro-identification device.

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Animals were examined twice daily for mortality and morbidity


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: From the start of treatment, all animals were examined daily for clinical signs of toxicity or changes in behaviour and appearance and each animal was given a detailed clinical examination once each week.

BODY WEIGHT: Yes
- Time schedule for examinations: Male body weights were recorded on the first day of dosing, at weekly intervals throughout the study and then on the day of necropsy.Female body weights were recorded on the first day of dosing and then at weekly intervals until the day of mating. Females were also weighed on Days 0, 7, 14 and 20 of gestation and on Days 0 (where required for dose volume calculations), 1, 4, 7, 14 and 21 of lactation and on the day of necropsy.
Females that failed to litter were weighed weekly until necropsy to calculate the dose volume to be administered but these data have not been reported. Furthermore, females, where all the pups have died in the litter prior to Day 21 of age, were weighed on Days 1, 4, 7, 14 and 21 of lactation.

FOOD CONSUMPTION AND COMPOUND INTAKE:
The amount of food consumed by each cage of males was recorded at weekly intervals during their pre-pairing and post-pairing periods.
Food intake of the females was recorded weekly during the pre-pairing period and over Days 0 to 4, 4 to 7, 7 to 10, 10 to 14, 14 to 17 and 17 to 20 of gestation and over Days 1 to 4, 4 to 7, 7 to 10, 10 to 14, 14 to 17 and 17 to 21 of lactation. Food intake of females, where all the pups have died in the litter prior to Day 21 of age, were recorded on Days 1, 4, 7, 14 and 21 of lactation.

WATER CONSUMPTION AND COMPOUND INTAKE: No

Oestrous cyclicity (parental animals):

For 21 days before the start of the pairing period, vaginal smears were taken daily by lavage. The smear was examined under light microscopy and the stage of the oestrous cycle was determined by the type of cell present.

Sperm parameters (parental animals):

For P and F1 generation: Sperm motility and concentration were assessed for all males killed at scheduled necropsy. The assessment was performed using fluid from one cauda epididymis. The cauda epididymis
was weighed separately. A sample of the epididymal fluid was retained in neutral buffered formalin, a smear was prepared for each Control and high dose male and at least 200 sperm per sample were examined for morphological abnormalities.
After weighing of the testes, the tunica albuginea of one testis was removed and the testis was snap frozen in liquid nitrogen and stored at -20 °C until required. For each Control and high dose male, the testis was thawed, homogenised and the resistant spermatids counted.

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- If yes, maximum of 8 pups/litter (4/sex/litter as nearly as possible); excess pups were killed and discarded.

PARAMETERS EXAMINED
The following parameters were examined in [P and F1] offspring: The total litter size was recorded after completion of parturition and daily thereafter. Numbers of each sex were recorded daily from Day 1 of age.
Pups were weighed individually on Days 1, 4, 7, 14 and 21 of age.
The anogenital distance of the pups in the F1 generation litters was measured on Day 1 of age.

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: All males were killed approximately six weeks after completion of the mating period.
- Maternal animals: Females with litters were killed on Day 21 of lactation at weaning of their litters. The remaining females, including those apparently non-pregnant and those where all the litter had died before Day 21 of age, were also killed at this time.

GROSS NECROPSY
The thoracic and abdominal cavities were opened by a ventral mid-line incision and the major organs and uterus were examined. The number of
implantation scars/sites for each female was recorded at necropsy. The uterus of any apparently non-pregnant female was stained with ammonium sulphide to confirm pregnancy status. The uterus was then retained in 70 % IDA (industrial denatured alcohol) for approximately seven days and then transferred to and retained in neutral buffered formaldehyde. Organs or tissues showing any macroscopic abnormalities were recorded and retained. For each male, one epididymis was processed for sperm evaluation.

HISTOPATHOLOGY / ORGAN WEIGHTS
The following organs were weighed after trimming of fat and other contiguous tissue (contralateral organs were weighed together):
adrenals prostate & seminal vesicles (incl. coagulating gland), brain, epididymides, spleen, kidneys, testes, liver, thyroids (including parathyroids), ovaries, uterus (incl. uterine cervix and oviducts), pituitary.

For all animals, either whole organs or samples of adrenals prostate & seminal vesicles (incl. coagulating gland), brain, epididymides, spleen, kidneys, testes, liver, thyroids (including parathyroids), ovaries, uterus (incl. uterine cervix and oviducts), pituitary, vagina , with the exception of the eyes, optic nerves, testes and epididymides, were preserved in neutral buffered formaldehyde. The eyes and optic nerves were fixed in Davidson’s fluid and the testes and epididymides were fixed in Bouin’s fixative for 24 hours and then transferred to neutral buffered formaldehyde.
Due to treatment related effects detected in the liver (males and females) and kidneys (males only) in Group 4, the livers of males and females and the kidneys of males only from the remaining dose groups were prepared and examined microscopically.

Postmortem examinations (offspring):

SACRIFICE
With the exception of pups culled on Day 4 of lactation, which were not further examined, a necropsy was conducted on all pups killed or found dead during lactation and all unselected pups on Day 21 of age. The pups were killed by an intraperitoneal injection of sodium pentobarbitone solution (for those up to the age of 14 days) or by exposure to carbon dioxide gas in a rising concentration (for older pups). A dead body weight was recorded for pups where organ weights were to be determined. The thoracic and abdominal cavities were opened by a ventral mid line incision and the major organs were examined.


GROSS NECROPSY
For one male and one female pup per litter the following tissues, brain, spleen, kidney, thymus, liver and all gross lesions were retained. All other pups had a gross macroscopic examination and only gross abnormalities were retained.

HISTOPATHOLOGY / ORGAN WEIGTHS
For one male and one female pup from each litter the following organs were weighed after trimming of fat and other contiguous tissue (left and right kidneys were weighed together): brain, spleen, kidney, thymus and liver.

Statistics:

Data were processed to give group mean values and standard deviations, where appropriate. Where the data allowed, the following methods were used for statistical analysis Groups 2, 3 and 4 against Group 1.
All statistical tests were two-sided with minimum significance levels of 5 % and 1 %. Non-parametric statistics were not routinely conducted. When used, Dunnett’s test was conducted regardless of the outcome of the analysis of variance (ANOVA) or analysis of covariance (ANCOVA).
Data were examined for unusually high or low values which could influence the statistical analysis and interpretation (possible outliers). After examining for any outliers, if the variances were clearly heterogeneous, transformations (e.g. log, double arcsine or square root) were used in an attempt to stabilise the variances. If the transformations failed, the data set was examined and a decision taken on further action.

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

no effects observed

Description (incidence and severity):

With the exception of yellow stained bedding seen in the cages of both sexes given 250 or 1000 mg/kg/day (which was considered to be a result of the colour of the test item), there were no clinical signs related to test item administration.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, non-treatment-related

Description (incidence):

There was only one early decedent, Female 188 given 1000 mg/kg/day, which was killed on Day 23 of gestation due to dystocia. There were no observations in the female reproductive organs that would have caused the dystocia. As there were no other instances of these macroscopic and microscopic findings in other animals this death was considered not to be test item related.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

From Week 3 for males given 250 mg/kg/day and Week 5 for males given 1000 mg/kg/day, animals gained slightly less weight than the Controls. These differences achieved statistical significance over Weeks 0 to 14 and Weeks 0 to 15 for males given 1000 mg/kg/day (p<0.05). Overall body weight gain (Weeks 0 to 16) was 4 % and 9 % lower than Controls, in the 250 mg/kg/day and 1000 mg/kg/day dose groups respectively, although not statistically significantly different from Controls. Males given 50 mg/kg/day gained weight at a similar rate to, or slightly higher than, the Controls throughout the study. This resulted in an overall body weight gain (Weeks 0 to 16) 3 % higher than Controls.
Females given 50, 250 or 1000 mg/kg/day gained slightly more weight than Controls during the pre-paring period, statistically significantly so for most of this period (p<0.05 and p<0.01), for females given 1000 mg/kg/day.
During the gestation period, females given 1000 mg/kg/day gained slightly more weight than Controls, (p<0.05 over Days 0 to 20 of gestation). Females given 50 or 250 mg/kg/day during gestation and all groups of females given the test item during lactation gained weight at a similar rate to the Controls.

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

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):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Microscopic treatment-related findings were seen in the liver in males and females and in the kidneys in males.
Liver:
Minimal or slight hepatocellular hypertrophy was seen in males at all dose levels and in females at the high dose level only. The incidence and severity of this finding were dose related in males.
Kidney:
A treatment-related cortical tubular basophilia was seen in a number of males at all dose levels. Cortical tubular basophilia was accompanied by cortical inflammatory cell infiltrate in some of the affected animals.

Histopathological findings: neoplastic:

no effects observed

Other effects:

no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

Effect levels (P0)

1

Dose descriptor:

LOAEL

Effect level:

50 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

histopathology: non-neoplastic

2

Dose descriptor:

NOAEL

Effect level:

250 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

histopathology: non-neoplastic

Target system / organ toxicity (P0)

1

Critical effects observed:

yes

Lowest effective dose / conc.:

50 mg/kg bw/day (nominal)

System:

urinary

Organ:

kidney

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

2

Critical effects observed:

yes

Lowest effective dose / conc.:

250 mg/kg bw/day (nominal)

System:

hepatobiliary

Organ:

liver

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Results: P1 (second parental generation)

General toxicity (P1)

Clinical signs:

no effects observed

Description (incidence and severity):

With the exception of yellow stained bedding seen in the cages of treated animals (which was considered to be a result of the colour of the test item), there were no clinical signs related to administration of the test item.

Mortality:

mortality observed, non-treatment-related

Description (incidence):

Female 390 (1000 mg/kg/day), was found dead on Day 23 of age; however no findings were seen at necropsy. As this was an isolated occurrence, this death was considered not to be test
item related.
Males 231, 238 and 243 (50 mg/kg/day) were found dead on Days 42, 41 and 40 of age, respectively; findings at necropsy suggested that these deaths were a result of dosing trauma.
Female 377 (1000 mg/kg/day) was killed on Day 18 of gestation due to an abnormal gait (at necropsy this animal was found to have suffered a dislocated hip).

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

Some statistically significant differences in food intake were noted between animals given the test item and Controls, however, these were considered to be incidental and not test item related.

Food efficiency:

no effects observed

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):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

At the end of the treatment period, there were dose related, statistically significant increases in group mean body weight adjusted liver (p<0.01), kidney (p<0.05 and p<0.01 for males given 250 or 1000 mg/kg/day, respectively) and thyroid weights (p<0.01) for males given the test item, when compared with Controls. There was also a dose related increase in body weight adjusted liver weight for all groups of females given the test item (p<0.05 and p<0.01 for females given 250 or 10 mg/kg/day, respectively) and increases in body weight adjusted kidney (p<0.01) and thyroid weights (p<0.01) for females given 1000 mg/kg/day, when compared with Controls.

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Microscopic treatment-related findings were seen in the liver in males and females and in the kidneys in males.
Liver:
Minimal or slight hepatocellular hypertrophy was seen in males and females given 250 or 1000 mg/kg/day.
Kidney:
A treatment-related increase in the incidence of cortical tubular basophilia was seen in a number of males at all dose levels.

Histopathological findings: neoplastic:

no effects observed

Other effects:

no effects observed

Reproductive function / performance (P1)

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

Effect levels (P1)

Dose descriptor:

LOAEL

Effect level:

50 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

histopathology: non-neoplastic

Target system / organ toxicity (P1)

1

Critical effects observed:

yes

Lowest effective dose / conc.:

50 mg/kg bw/day (nominal)

System:

urinary

Organ:

kidney

Treatment related:

yes

Dose response relationship:

no

Relevant for humans:

not specified

2

Critical effects observed:

yes

Lowest effective dose / conc.:

250 mg/kg bw/day (nominal)

System:

hepatobiliary

Organ:

liver

Treatment related:

yes

Dose response relationship:

yes

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Description (incidence and severity):

With the exception of yellow stained bedding seen in the cages of treated animals (which was considered to be a result of the colour of the test item), there were no clinical signs related to administration of the test item.

Dermal irritation (if dermal study):

not examined

Mortality / viability:

mortality observed, non-treatment-related

Description (incidence and severity):

Female 390 (1000 mg/kg/day), was found dead on Day 23 of age; however no findings were seen at necropsy. As this was an isolated occurrence, this death was considered not to be test item related.
Males 231, 238 and 243 (50 mg/kg/day) were found dead on Days 42, 41 and 40 of age, respectively; findings at necropsy suggested that these deaths were a result of dosing trauma. Female 377 (1000 mg/kg/day) was killed on Day 18 of gestation due to an abnormal gait (at necropsy this animal was found to have suffered a dislocated hip).

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

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

Sexual maturation:

no effects observed

Description (incidence and severity):

There was no effect of the test item on the age of balano-preputial separation.
For females there was a statistically significant (p<0.01) delay in vaginal opening at 1000 mg/kg/day. For the Control animals the group mean was 31.3 days and for females given 1000 mg/kg/day the group mean was 32.5 days. As the mean difference between these groups was only just over one day, this finding was considered not to be of biological significance.

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

At the end of the treatment period, there were dose related, statistically significant increases in group mean body weight adjusted liver (p<0.01), kidney (p<0.05 and p<0.01 for males given 250 or 1000 mg/kg/day, respectively) and thyroid weights (p<0.01) for males given the test item, when compared with Controls. There was also a dose related increase in body weight adjusted liver weight for all groups of females given CA4920 (p<0.05 and p<0.01 for females given 250 or 1000 mg/kg/day, respectively) and increases in body weight adjusted kidney (p<0.01) and thyroid weights (p<0.01) for females given 1000 mg/kg/day, when compared with Controls.

Gross pathological findings:

no effects observed

Histopathological findings:

effects observed, treatment-related

Description (incidence and severity):

Microscopic treatment-related findings were seen in the liver in males and females and in the kidneys in males.
Liver:
Minimal or slight hepatocellular hypertrophy was seen in males and females given 250 or 1000 mg/kg/day.
Kidney:
A treatment-related increase in the incidence of cortical tubular basophilia was seen in a number of males at all dose levels

Other effects:

no effects observed

Description (incidence and severity):

There was no effect of treatment on sperm parameters.
The number of follicles in the ovaries of females was similar across all the groups, including Controls. Occasional differences were considered a likely consequence of individual animal variability and were considered not to be related to treatment.

Developmental neurotoxicity (F1)

Behaviour (functional findings):

not examined

Developmental immunotoxicity (F1)

Developmental immunotoxicity:

not examined

Effect levels (F1)

1

Dose descriptor:

LOAEL

Generation:

F1

Effect level:

50 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

histopathology: non-neoplastic

2

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

50 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

histopathology: non-neoplastic

Target system / organ toxicity (F1)

1

Critical effects observed:

yes

Lowest effective dose / conc.:

50 mg/kg bw/day (nominal)

System:

hepatobiliary

Organ:

liver

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

2

Critical effects observed:

yes

Lowest effective dose / conc.:

250 mg/kg bw/day (nominal)

System:

urinary

Organ:

kidney

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Results: F2 generation

General toxicity (F2)

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

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

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Adjusted liver (male) and kidney (female) weights were significantly increased in animals given 1000 mg/kg/day, when compared with Controls.

Gross pathological findings:

no effects observed

Histopathological findings:

not examined

Other effects:

no effects observed

Developmental neurotoxicity (F2)

Behaviour (functional findings):

not examined

Developmental immunotoxicity (F2)

Developmental immunotoxicity:

not examined

Effect levels (F2)

Dose descriptor:

NOAEL

Generation:

F2

Effect level:

1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

organ weights and organ / body weight ratios

Target system / organ toxicity (F2)

Critical effects observed:

no

Lowest effective dose / conc.:

1 000 mg/kg bw/day (nominal)

System:

hepatobiliary

Organ:

kidney

liver

Overall reproductive toxicity

Reproductive effects observed:

no

Applicant's summary and conclusion

Conclusions:

No effect on reproductive performance, mating behaviour, conception or pup development in either generation was noted during the course of the study and therefore, for effects on
reproduction, the No Observed Adverse Effect Level was considered to be 1000 mg/kg/day.
In terms of general toxicity, a marginal decrease in male body weight gain was seen at 250 or 1000 mg/kg/day. Liver, kidney and thyroid gland weights were increased in animals given the test item when compared with Controls and were associated, in the parental animals of both generations, with microscopic findings of hepatocellular hypertrophy and increased renal cortical tubular basophilia.

Executive summary:

Effects of the test item on the integrity and performance of the male and female reproductive systems, including gonadal function, the oestrous cycle, mating behaviour, conception, gestation, parturition, lactation and weaning, and the growth and development of the offspring over two successive generations in the rat, when administered orally by gavage.

Four groups of 24 male and 24 female rats of the Crl:WI(Han) strain were dosed by oral gavage at dose levels of 0 (1 % aqueous carboxymethylcellulose), 50, 250 or 1000 mg/kg/day of the test item for 10 weeks before pairing, during pairing, gestation, lactation and until necropsy. Four groups of 24 male and 24 female F1 generation animals were selected from the weaned P generation litters; these animals were dosed once daily by oral gavage at dose levels of 0, 50, 250 or 1000 mg/kg/day from Day 21 of age for approximately 10 weeks before pairing, during pairing, gestation and lactation and until necropsy. All animals were examined for effects on general condition, body weight and food consumption. The stage of the oestrous cycle was recorded for at least 21 days prior to pairing for P and F1 females, and during the pairing period vaginal smears were taken daily until sperm were found in the smear. The females were allowed to litter and rear their offspring to weaning. The day of sexual development was recorded for all selected F1 animals. Anogenital distance was recorded for all F1 generation pups on Day 1 of age. The P and F1 parental males were subjected to macroscopic necropsy once successful littering was completed. The testes and epididymides were removed and weighed and sperm evaluation was conducted. The P and F1 parental females were killed and subject to necropsy on Day 21 of lactation. A macroscopic necropsy was performed and the number of implantation scars was recorded. For the P and F1 parental males and females a selection of organs were weighed, fixed and microscopically examined. Unselected P generation pups and all F1 generation pups were killed on Day 21 of age. A gross macroscopic necropsy was performed on all pups and, for one male and one female pup per litter from the P and F1 generations, brain, liver, kidney, spleen and thymus weights were recorded. Homogenisation resistant testicular spermatid counts were performed for the P and F1 parental males and ovarian follicle evaluation for the F1 generation parental females.

There were no deaths or adverse clinical observations considered to be related to the test item administration.

A marginal decrease in group mean body weight gain was evident in males given 250 or 1000 mg/kg/day over the duration of the dosing period, when compared with Controls; however, all other groups given the test item across both generations gained weight at a similar rate to, or slightly higher than, Controls throughout the study. There was no effect on food intake for any dose group across either generation, when compared with Control animals. Oestrous cycles, fertility and mating data in both generations were unaffected by treatment with the test item.

There were no test item related effects on the number of pups born or cumulative pup survival for the P or F1 generation litters, when compared with Controls.

There was no biologically significant effect on the age of sexual maturity for males and females and there was also no effect of treatment on the anogenital distance for F1 generation pups.

There was a dose-related increase in group mean body weight adjusted liver weights for all groups of P and F1 generation parental males, P Generation parental females given 1000 mg/kg/day, F1 parental females given 250 or 1000 mg/kg/day, Day 21 of age P

generation female pups and F1 generation male pups given 1000 mg/kg/day. There was a dose-related increase in group mean body weight adjusted kidney weights for all test item treated P generation parental males, P generation parental females given 1000 mg/kg/day, F1 generation parental males given 250 mg/kg/day, F1 generation parental males and females given 1000 mg/kg/day and for Day 21 of age P and F1 generation female pups given 1000 mg/kg/day. Group mean adjusted thyroid gland weights were higher than Controls for P and F1 generation parental males and females given 1000 mg/kg/day P generation parental males given 250 mg/kg/day and F1 generation parental males given 50 or 250 mg/kg/day. There was no effect of treatment on sperm parameters or spermatid counts in the P or F1 generation males or ovarian follicles of F1 generation females.

Treatment-related microscopic findings in the P generation were found in the liver (hepatocellular hypertrophy) in males at all dose levels and in females given 1000 mg/kg/day only and in the kidneys (cortical tubular basophilia) in males at all dose levels. Treatmentrelated microscopic findings in the F1 generation were similar to those seen in the P generation with hepatocellular hypertrophy in males and females given 250 or 1000 mg/kg/day and an increased incidence of cortical tubular basophilia in the kidneys in males at all dose levels.

No effect on reproductive performance, mating behaviour, conception or pup development in either generation and therefore, for effects on reproduction were observed, the No Observed Adverse Effect Level was considered to be 1000 mg/kg/day.