Cinnamonitrile

Toxicity to reproduction

Administrative data

Endpoint:

reproductive toxicity, other

Remarks:

reproductive organ toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Data is from peer- reviewed journal

Data source

Reference

Reference Type:

publication

Title:

A repeated dose 28-day oral toxicity study of β-bromostyrene in rats

Author:

Atsushi Ono ; Katsumi Kobayashi; Hideki Serizawa; Tomoko Kawamura, Hina Kato, Mariko Matsumoto, Mika Takahashi, Mutsuko Hirata-Koizumi, Yuko Matsushima and Akihiko Hirose

Year:

2015

Bibliographic source:

Fundamental toxicological sciences vol.2(4)191-200,2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: TG 407

Principles of method if other than guideline:

Subacute repeated dose reproductive organ toxicity study of (2-bromovinyl)benzene in rat

GLP compliance:

not specified

Limit test:

no

Justification for study design:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

β-bromostyrene

EC Number:

203-131-3

EC Name:

β-bromostyrene

Cas Number:

103-64-0

Molecular formula:

C8H7Br

IUPAC Name:

(2-bromovinyl)benzene

Constituent 2

Reference substance name:

β-bromostyrene

IUPAC Name:

β-bromostyrene

Details on test material:

- Name of test material (as cited in study report):β -Bromostyrene ((2-bromovinyl)benzene)
- Molecular formula :C8H7Br
- Molecular weight :183.0473 g/mole
- Substance type:Organic
- Physical state:Liquid
- Impurities (identity and concentrations):0.4%

Specific details on test material used for the study:

- Name of test material (as cited in study report):β -Bromostyrene ((2-bromovinyl)benzene)
- Molecular formula :C8H7Br
- Molecular weight :183.0473 g/mole
- Substance type:Organic
- Physical state:Liquid
- Impurities (identity and concentrations):0.4%

Test animals

Species:

rat

Strain:

Sprague-Dawley

Remarks:

Crl:CD(SD)

Details on species / strain selection:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Atsugi Breeding Center of Charles River Japan, Inc. (Kanagawa, Japan)
- Age at study initiation: (P) x wks: 6 weeks;
(F1) x wks: No data available
- Weight at study initiation:
(P) Males: 182-216g;
Females: 145-171 g;
(F1) Males: No data available
Females: No data available

- Fasting period before study: No data available

- Housing: Animals were individually housed in wire-mesh steel bracket cages (W 250 × D 350 × H 200 mm) and identified by using ear tags.

- Use of restrainers for preventing ingestion (if dermal): No data available

- Diet (e.g. ad libitum): pellet diet (CRF-1, Oriental Yeast Co., Ltd., Tokyo, Japan) ad libitum

- Water (e.g. ad libitum): Tap water ad libitum

- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21-23°C
- Humidity (%): 49-66%
- Air changes (per hr): 10-15 times/hr
- Photoperiod (hrs dark / hrs light): 12 hr per /day (light on/off, 7:00/19:00)

IN-LIFE DATES: From: To: No data available

Administration / exposure

Route of administration:

oral: gavage

Type of inhalation exposure (if applicable):

not specified

Vehicle:

corn oil

Details on exposure:

VEHICLE
- Justification for use and choice of vehicle (if other than water): Corn oil
- Concentration in vehicle: 0, 30, 125 and 500 mg/kg/day
- Amount of vehicle (if gavage): 5 ml/kg
- Lot/batch no. (if required): Lot no. WKJ3948
- Purity: No data available

Details on mating procedure:

No data available

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

28 days

Frequency of treatment:

Once daily

Details on study schedule:

No data available

Doses / concentrations

Remarks:

0, 30, 125 and 500 mg/Kg/day

No. of animals per sex per dose:

Total: 72
0 mg/kg/day: 6 male, 6 female
30 mg/kg/day: 6 male, 6 female
125 mg/kg/day: 6 male, 6 female
500 mg/kg/day: 6 male, 6 female

For recovery period:
0 mg/kg/day: 6 male, 6 female
500 mg/kg/day: 6 male, 6 female

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Dose level were selected based on results obtained from 14-days range finding study using the same strains of rats. All males and females in the 1000 mg/kg died. Increases in relative liver and kidney weights were observed in 300 mg/kg group. Therefore, for the present study high dose was set at 500 mg/kg/day and middle and low doses was set at 125 and 30 mg/kg/day.

- Rationale for animal assignment (if not random): Stratified random sampling based on body weight

- Other: 6 male and 6 female of 0 and 500 mg/kg/day dose group kept without treatment as a recovery group for 14 days

Positive control:

No data available

Examinations

Parental animals: Observations and examinations:

Parental animals observation and examinations
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: 2-3 times daily during the dosing period and once daily during the recovery period
- Cage side observations checked in table [No.?] were included. Clinical signs of morbidity and mortality were observed.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: before the start of dosing and once a week during the dosing and recovery periods.

BODY WEIGHT: Yes
- Time schedule for examinations: Body
weight was recorded before dosing on Days 1, 4, 7, 10, 14, 17, 21, 24, and 28 of the dosing period and on Days 1, 3, 7, 10, and 14 of the recovery period.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes, Food consumption was measured on the same days as body weights.
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No data avaialbe

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
- Time schedule for examinations: At Week 4 of the dosing period and Week 2 of the recovery period.

OTHER:
HAEMATOLOGY: Yes
- Time schedule for collection of blood: The day after the end of dosing and recovery period
- Anaesthetic used for blood collection: Yes ,blood was collected from abdominal aorta under deep anesthesia after overnight starvation
- Animals fasted: Yes, overnight fasted.
- How many animals: From all 72 animals
- Parameters checked in table [No.?] were examined.: RBC, Hemoglobin, hematocrit, Mean corpuscular volume, Mean corpuscular hemoglobin, reticulocyte, platelets, prothrombin volume, WBC , lymphocytes, neutrophils,
eosinophils, basophils, monocytes, large unstained cells and blood clotting parameters, such as prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen level (FIB) were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: At the end of dosing period and at the end of recovery period
- Animals fasted: Yes, overnight fasted.
- How many animals: From all 72 animals
- Parameters checked in table [No.?] were examined.: alkaline phosphatase (ALP), total cholesterol (T-CHO), triglyceride (TG), phospholipid (PL), total bilirubin (T-BIL), glucose (GLU), blood urea nitrogen (BUN), creatinine (CRNN), sodium (Na), potassium (K), chlorine (Cl), calcium (Ca), inorganic phosphorus (P), total protein (TP), albumin (ALB), and albumin/globulin (A/G) ratio. Plasma isolated from heparinized blood was analyzed for aspartate and alanine aminotransferases (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and γ-glutamyl transpeptidase (γ-GTP).

URINALYSIS: Yes
- Time schedule for collection of urine: Conducted during week 4 in dosing period and week 2 in recovery period
- Metabolism cages used for collection of urine: No data
- Animals fasted: Yes, for 4 hours
- Parameters checked in table [No.?] were examined.: pH, proteins, ketone bodies, glucose, occult blood, bilirubin, urobilinogen, color, sediments, urine volume and osmolality were examined.

NEUROBEHAVIOURAL EXAMINATION:Yes
- Time schedule for examinations: A the end of dosing and recovery periods
- Dose groups that were examined: All animals were examined
- Battery of functions tested: sensory activity / grip strength / motor activity / other: Auditory, aaproach, touch, tail pinch response, pupilary, aerial righting reflexes, grip strengths and motor activity was recorded.

Oestrous cyclicity (parental animals):

No data available

Sperm parameters (parental animals):

No data available

Litter observations:

No data available

Postmortem examinations (parental animals):

Organ weight:
Absolute and relative weight of brain, adrenals, thymus, spleen, heart, liver, kidneys, testes, epididymides, ovaries and uterus were weighed.

GROSS PATHOLOGY: Yes
Organs and tissues of the whole body, including external surfaces, head, breast and abdomen were observed macroscopically.

The cerebrum, cerebellum, spinal cord (chest), sciatic nerve, pituitary gland, thyroid, parathyroids, adrenal glands, thymus, spleen, submandibular lymph nodes, mesenteric lymph nodes, heart, trachea, lung (including bronchial), stomach, duodenum, jejunum, ileum (including Peyer's patches), cecum, colon, rectum, liver, kidneys, urinary bladder, testes, epididymides, prostate, ovaries, uterus, sternum (including bone marrow), femur (including bone marrow), and femoral skeletal muscle were fixed in 10% phosphate-buffered formalin. The eyeballs and optic nerves were fixed in phosphate-buffered 3 vol % glutaraldehyde/2.5 vol % formalin, and the testes and epididymides were fixed in Bouin’s solution.

Paraffin sections for microscopic examination were routinely prepared and stained with hematoxylin-eosin.

In the control and high dose groups sacrificed at the end of the dosing period, all preserved organs were examined under a light microscope.

If treatment-related histopathological changes were found, the same tissues were examined for low and middle dose groups and the recovery group.

HISTOPATHOLOGY: Yes
Heart, Intestine, rectum, Kidney, Liver, Prostate, Skeletal muscle, Spleen, Glandular stomach, Thyroid and Urinary bladder were examined.

Postmortem examinations (offspring):

No data available

Statistics:

Statistical analysis were performed by using Bartlett’s test for homogeneity of distribution for quantitative data in open field observation, functional observation and urinalysis, grip strengths, motor activity, body weight, food and water consumption, hematological and blood biochemistry findings, and organ weights. The Dunnett’s multiple comparison test and the Dunnett’s-type mean rank sum test were conducted for homogenous and non-homogenous distribution, respectively to compare the control and individual treatment groups. Parametric data obtained during or after the recovery period were analyzed by F-test for homogeneity of distribution. For comparison, the Student’s t-test and the Aspin-Welch’s t-test were conducted for homogenous and non-homogenous distribution.

Reproductive indices:

No data available

Offspring viability indices:

No data available

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

effects observed, non-treatment-related

Dermal irritation (if dermal study):

not specified

Mortality:

mortality observed, non-treatment-related

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Food efficiency:

not specified

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

effects observed, treatment-related

Ophthalmological findings:

not specified

Haematological findings:

effects observed, treatment-related

Clinical biochemistry findings:

effects observed, treatment-related

Urinalysis findings:

effects observed, treatment-related

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not specified

Reproductive performance:

not specified

Details on results (P0)

Mortality: When treated with 500 mg/kg/day, One female rat found dead on Day 3.
The cause of death was unclear.

Clinical signs
When treated with 500 mg/kg/day, Decreases in spontaneous movement during weeks 3 and 4 were observed in male and female rat as compared to control.
However, no abnormalities were observed in the general conditions thereafter during the dosing period.
No clinical signs were observed in any animal during the recovery period.

Body weight: When treated with 125 mg/kg/day, significantly increased body weight were observed in female rat on days 17-24 during the dosing period.

Food consumption: When treated with 500 mg/kg/day, Significant decreased in food consumption at day 4 were observed in male and female rat in dosing period and in females at days 7 and 14 in recovery period.
When treated with 125 mg/kg/day, significant increased in food consumption at days 7-21 were observed in female rats as compared to control.

Water consumption: When treated with 125 mg/kg/day, significant decrease in water consumption was observed in female rats during Week 4 of the dosing period as compared to control. However, this change was not observed in the high dose group. No significant differences were seen with water consumption for either sex in the recovery group.

Haematology:
When treated with 500 mg/kg/day, decreased mean corpuscular hemoglobin (MCH) during dosing and eosinophils in recovery period were observed in male rat and increased Reticulocyte and decreased mean corpuscular hemoglobin concentration (MCHC) during dosing and increase monocytes at recovery period were observed in female rats as compared to control.

When treated with 125 mg/kg/day, decreased activated partial thromboplastin time and increased fibrinogen level were observed in female rats as compared to control.

Clinical chemistry:
When treated with 500 mg/kg/day, significant increased in total protein level in male and female rats, Ca, P and albumin level and decrease in aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase and creatinine in male rats and significant increased total cholesterol, triglycerides, phospholipids and Cl level in female rats at the end of dosing as compared to control.
Significant increased in triglycerides level was observed in female rats after the recovery period.
When treated with 125 mg/kg/day, significant decrease in aspartate aminotransferase, lactate dehydrogenase level and significant increased in Ca level in male rats and significant increased total cholesterol, phospholipids level in female rats as compared to control.

Urinanalysis:
When treated with 500 mg/kg/day, significant increases in urine volume in male and female rats, decrease in urine osmolality and small round epithelial cells in sediments were observed in male rats during week 4 of dosing period as compared to control.

When treated with 125 mg/kg/day, significant increases in urine volume and significant decrease in urine osmolality were observed in male rats as compared to control.
No significant differences were seen in urine volume, osmolality and qualitative measurements for either sex compared with the control groups during Week 2 of the recovery period.

Neurobehaviour:
When treated with 500 mg/kg/day, significant decrease in landing foot splay was observed in male rats during week 2 of the recovery period.
However, it was determined to be incidental because this sign was not observed during Week 4 of the dosing period.
Significant decrease in forelimb grip strength was observed in male rats during Week 2 of the recovery period, but this change was not observed during week 4 of dosing period.
Significant decrease was observed in male rats during week 2 of recovery period.
No significant change was observed in any male or female rats receiving the test substance during week 4 of the dosing period.

When treated with 125 mg/kg/day, significant increase in hindlimb grip strength was observed in female rats during week 4 of the dosing period as compared to control.
However, this was not observed in the high dose group.


Organ weights: When treated with 500 mg/kg/day, Significant increase in absolute and relative liver weight in male and female rats, significant increase in absolute and relative kidney weights and significant decrease in absolute testes weight in male rats and significant increase in relative kidney weights in female rats were observed as compared to control during dosing period.
Significant increase in relative liver and heart weight was observed in female rats as compared to control at the end of recovery period.
When treated with 125 mg/kg/day, Significant increase in relative liver weight and decrease in brain weight were observed in female rats at the end of the recovery period.
When treated with 30 mg/kg/day, decreases in relative spleen weight were observed in male rats as compared to control at the end of the recovery period.
Change in absolute testes weight at the end of dosing period in male rat, as well as increase in relative heart weight at 500 mg/kg/day in females at the end of the recovery period, relative brain weight at 125 mg/kg in females and relative spleen weight at 30 mg/kg in male are slight and/or lacked dosedependency.

Gross pathology: When treated with 500 mg/kg/day, excess fluids in the abdominal and thoracic cavities, an enlarged liver, and dark red foci in the glandular stomach and unilateral small thyroids observed in female rat and enlargement of liver was observed in male rats at the end of dosing period.
Enlargement of liver was observed in male rats at the end of recovery period.
When treated with 125 mg/kg/day, dark red foci in the lung in one male rat and dark red foci in the glandular stomach in one female rat were observed at end of the dosing period.
When treated with 30 mg/kg/day, unilateral small thyroids in one female rat were observed at end of the dosing period.

Histopathology:
When treated with 500 mg/kg/day, minimal to mild degree of eosinophilic bodies in tubular cells, Mild degeneration of renal tubular and minimal hyaline casts in kidneys, minimal to mild centrilobular hypertrophy of hepatocytes in liver and minimal hypertrophy of follicular cells in thyroids were observed in male rats and atrophy of Peyer’s patch in the ileum, dilation of the renal tubes with centrilobular necrosis and congestion in the liver, focal hemorrhage and accumulation of foamy cells in the lung, atrophy of the mesenteric and submandibular lymph nodes, an increase in hematopoiesis and atrophy of white pulp in the spleen, erosion in the glandular stomach, atrophy of the thymus, and a remnant of ultimobranchial bodies in the thyroid were observed in female rats as compared to control.
Minimal Lymphocyte infiltration in Prostate gland was observed in male rat at the end of dosing period was considered to be incidental findings due to the apparent situation or histopathological properties.
Minimal Tubular regeneration, mild to minimal Eosinophilic body in tubular cells interstitial mineralization Kidney and Hypertrophy of follicular cells in thyroid of male rat and Periportal vacuolation of hepatocytes in liver of female rat were observed at the recovery period.
When treated with 125 mg/kg/day, minimal to mild degree of eosinophilic bodies in tubular cells in kidney were observed in male rat and minimal hypertrophy of follicular cells in thyroids were observed in female rats as compared to control.
Other changes at the end of the dosing and/or recovery periods observed in the heart, rectum, kidneys, liver, prostate, skeletal muscle, spleen, stomach, thyroid, and urinary bladder were considered to be incidental findings due to the apparent situation or histopathological properties.

Effect levels (P0)

1

Dose descriptor:

NOAEL

Effect level:

125 mg/kg bw/day

Based on:

test mat.

Sex:

male

Basis for effect level:

clinical signs

mortality

body weight and weight gain

food consumption and compound intake

haematology

clinical biochemistry

urinalysis

organ weights and organ / body weight ratios

gross pathology

histopathology: non-neoplastic

Remarks on result:

other: No effect observed

2

Dose descriptor:

NOAEL

Effect level:

500 mg/kg bw/day

Based on:

test mat.

Sex:

female

Basis for effect level:

organ weights and organ / body weight ratios

Remarks on result:

other: NO effect on reproductive oragn

Target system / organ toxicity (P0)

Critical effects observed:

not specified

System:

other: not specified

Organ:

not specified

Treatment related:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Results: P1 (second parental generation)

General toxicity (P1)

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality:

not specified

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Reproductive function / performance (P1)

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not specified

Reproductive performance:

not specified

Effect levels (P1)

Dose descriptor:

other: not specified

Based on:

not specified

Sex:

not specified

Basis for effect level:

other: not specified

Remarks on result:

other: not specified

Target system / organ toxicity (P1)

Critical effects observed:

not specified

System:

other: not specified

Organ:

not specified

Treatment related:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Results: F1 generation

General toxicity (F1)

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality / viability:

not specified

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Sexual maturation:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Histopathological findings:

not specified

Other effects:

not specified

Developmental neurotoxicity (F1)

Behaviour (functional findings):

not specified

Developmental immunotoxicity (F1)

Developmental immunotoxicity:

not specified

Effect levels (F1)

Dose descriptor:

other: not specified

Generation:

other: not specified

Based on:

not specified

Sex:

not specified

Basis for effect level:

other: not specified

Remarks on result:

other: not specified

Target system / organ toxicity (F1)

Critical effects observed:

not specified

System:

other: not specified

Organ:

not specified

Treatment related:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Results: F2 generation

General toxicity (F2)

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality / viability:

not specified

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Sexual maturation:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Histopathological findings:

not specified

Other effects:

not specified

Developmental neurotoxicity (F2)

Behaviour (functional findings):

not specified

Developmental immunotoxicity (F2)

Developmental immunotoxicity:

not specified

Effect levels (F2)

Dose descriptor:

other: not specified

Generation:

other: not specified

Based on:

not specified

Sex:

not specified

Basis for effect level:

other: not specified

Remarks on result:

other: not specified

Target system / organ toxicity (F2)

Critical effects observed:

not specified

System:

other: not specified

Organ:

not specified

Treatment related:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Overall reproductive toxicity

Reproductive effects observed:

not specified

Treatment related:

not specified

Relation to other toxic effects:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Applicant's summary and conclusion

Conclusions:

NOAEL was considered to be 125 mg/kg/day for male and 500 mg/kg/day for female when Sprague Dawley [Crl:CD()SD] male and female rats treated with β-bromostyrene

Executive summary:

In a Subacute repeated dose toxicity study, Sprague Dawley [Crl:CD()SD] male and female rats treated with β-bromostyreneorally by gavage in the concentration of 0, 30, 125 and 500 mg/kg/day.One female rat found dead on Day 3 and Decreases in spontaneous movement during weeks 3 and 4 were observed in male and female rats. No clinical signs were observed in any animal during the recovery period.Significantly increased body weight was observed in female rat on days 17-24 during the dosing period and significant decrease in water consumption was observed in female rats during week 4 of the dosing period a 125 mg/kg/day dose group as compared to control. Significant decreased in food consumptionat day 4 were observed in male and female rat in dosing period and in females at days 7 and 14 in recovery period at 500 mg/kg/day andsignificant increased in food consumption at days 7-21were observed in female rats at 125 mg/kg/day as compared to control.Decreased mean corpuscular hemoglobin (MCH) during dosing and eosinophils in recovery period were observed in male rat and increased Reticulocyte and decreased mean corpuscular hemoglobin concentration (MCHC) during dosing and increase monocytes at recovery period were observed in female rats and significant increased in total protein level in male and female rats, Ca, P and albumin level and decrease in aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase and creatinine in male rats and significant increased in total cholesterol, triglycerides, phospholipids and Cl level in female rats at the end of dosing. Significant increased in triglycerides level was observed in female rats after the recovery period at 500 mg/kg/day. Decreasedactivated partial thromboplastin time and increased fibrinogen level were observed in female rats andsignificant decrease in aspartate aminotransferase, lactate dehydrogenase level and significant increased in Ca level in male rats and significant increased in total cholesterol, phospholipids level in female rats observed at 125 mg/kg/day as compared to control. Significant increases in urine volume in male and female rats, decrease in urine osmolality and small round epithelial cells in sediments were observed in male rats during week 4 of dosing period at 500 mg/kg/day and significant increases in urine volume and significant decrease in urine osmolality were observed in male rats at 125 mg/lg/day as compared to control. No significant differences were seen in urine volume, osmolality and qualitative measurements for either sex compared with the control groups during week 2 of the recovery period. Significant decrease in landing foot splay and forelimb grip strength was observed in male rats during week 2 of the recovery period. However, it was determined to be incidental because this sign was not observed during week 4 of the dosing period at 500 mg/kg/day. Significant decrease in forelimb grip strength was observed in male rats during week 2 of recovery period. No significant change was observed in any male and female rats receiving the test substance during week 4 of the dosing period. Significant increase in hindlimb grip strength was observed in female rats during week 4 of the dosing period at 125 mg/kg/day as compared to control. However, this was not observed in the high dose group. Similarly, Significant increase in absolute and relative liver weight in male and female rats, significant increase in absolute and relative kidney weights and significant decrease in absolute testes weight in male rats and significant increase in relative kidney weights in female rats in dosing period and Significant increase in relative liver and heart weight was observed in female rats at 500 mg/kg/day as compared to control at the end of recovery period. Significant increase in relative liver weight and decrease in brain weight were observed at 125 mg/kg/day in female rats at the end of the recovery period. In addition, excess fluids in the abdominal and thoracic cavities, an enlarged liver, and dark red foci in the glandular stomach and unilateral small thyroids observed in female rat and enlargement of liver was observed in male rats at the end of dosing period. Enlargement of liver was observed in male rats at the end of recovery period in 500 mg/lg/day. Dark red foci in lung in one male rat and dark red foci in the glandular stomach in one female rat were observed at end of the dosing period at 125 mg/kg/day dose group. Minimal to mild degree of eosinophilic bodies in tubular cells, Mild degeneration of renal tubular and minimal hyaline casts in kidneys, minimal to mild centrilobular hypertrophy of hepatocytes in liver and minimal hypertrophy of follicular cells in thyroids were observed in male rats and atrophy of Peyer’s patch in the ileum, dilation of the renal tubes with centrilobular necrosis and congestion in the liver, focal hemorrhage and accumulation of foamy cells in the lung, atrophy of the mesenteric and submandibular lymph nodes, an increase in hematopoiesis and atrophy of white pulp in the spleen, erosion in the glandular stomach, atrophy of the thymus, and a remnant of ultimobranchial bodies in the thyroid were observed in female rats at 500 mg/kg/day as compared to control. Minimal Tubular regeneration, mild to minimal Eosinophilic body in tubular cells interstitial mineralization Kidney and Hypertrophy of follicular cells in thyroid of male rat and Periportal vacuolation of hepatocytes in liver of female rat were observed at the recovery period. Minimal to mild degree of eosinophilic bodies in tubular cells in kidney was observed in male rat and minimal hypertrophy of follicular cells in thyroids was observed in female rats at 125 mg/kg/day as compared to control. No effects were observed on reproductive organs of treated female rats as compared to control. Therefore, NOAEL was considered to be 125 mg/kg/day for male and 500 mg/kg/day for female when Sprague Dawley [Crl:CD()SD] male and female rats treated with β-bromostyrene