2,2-dimethyl-1,3-propanediyl dioleate

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

other: Data sharing dispute

Adequacy of study:

key study

Study period:

17 Feb - 30 Mar 2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

assessment report

Reference

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

other: data sharing dispute

Adequacy of study:

key study

Study period:

Nov - Dec 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Reason / purpose for cross-reference:

assessment report

Reason / purpose for cross-reference:

assessment report

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): only trade name given
- Substance type: pentaerythritol ester, tetrasubstituted
- Physical state: pale yellow liquid
- Analytical purity: 98%
- Composition of test material, percentage of components: pentaerythritol tetrasubstituted with fatty acids (C7: 52%; C8 branched: 25%; C9: 10%; C10: 13%)
- Stability under test conditions: 5 weeks

Species:

rat

Strain:

other: Alpk:APfSD

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Zeneca Pharmaceuticals, Alderly Park, Macclesfield, Cheshire, UK
- Age at study initiation: 28 d
- Weight at study initiation: 148.45 g (males); 122.6 g (females)
- Housing: sexes separately, five per cage, cages had measurements of 26.5 x 50.0 x 20.0 cm and were constructed of stainless steel mesh with one solid side.
- Diet: CT1 diet; Special Diets Services Limited, Witham, Essex, UK
- Water: tap water, ad libitum
- Acclimation period: approx. 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23
- Humidity (%): 45-65 (71 at one occasion)
- Air changes (per hr): 25-30
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: November 1992 To: December 1992

Route of administration:

oral: feed

Vehicle:

other: in diet

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: All diet preparations were based on CT1 diet (Special Diets Services Limited, Witham, Essex, UK). They were prepared by grinding the appropriate amount of test substance with 1 kg of milled CT1 diet. This premix was then added to 14 kg of diet and mixed thoroughly with a Pharma Blender Model PMA 100S (T K Filder).

DIET PREPARATION
- Rate of preparation of diet (frequency): 15 kg batches
- Mixing appropriate amounts with (Type of food): CT1 diet (Special Diets Services Limited, Witham, Essex, UK)
- Storage temperature of food: - 20°C, stored at room temperature for usage up to 14 days

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Chemical stability was determined for diet preparations over a period of 5 weeks following storage at room temperatureT or at -20°C.
Samples were extracted by chemical shaking with ethyl acetate. The supernatant was diluted with ethyl acetate to give solutions containing appropriate concentrations of the test substance. Extracts were analysed by gas chromatography using flame ionisation detection. The extract concentration was calculated by reference to data from a standard containing a known concentration.

Duration of treatment / exposure:

daily

Frequency of treatment:

28 d

Remarks:

Doses / Concentrations:
1000 ppm, 5000 ppm, 12500 ppm
Basis:
nominal in diet

Remarks:

Doses / Concentrations:
112, 562, 1450 mg/kg bw/d
Basis:
other: actual ingested for males

Remarks:

Doses / Concentrations:
119, 586, 1613 mg/kg bw/d
Basis:
other: actual ingested for females

No. of animals per sex per dose:

5

Control animals:

yes

Details on study design:

Dose selection rationale: Based on results of preliminary feeding studies

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily
- Cage side observations checked: changes in clinical condition and behaviour and significant changes were recorded.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: on Days 8, 15, 22, 29
- observations included, but were not limited to the assessment of autonomic function (e.g. lacrimation, salivation, piloerection, exophthalmus, urination, defecation, pupillary function, ptosis); description, incidence and severity of any convulsions, tremors, abnormal motor function, alteration in respiration, reactivity to stimuli, changes in the level of arousal, sensorimotor responses

BODY WEIGHT: Yes, measurement in replicate order immediately before feeding and at the same day once a week until termination.

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption for each animal determined and mean daily diet consumption calculated as mg food/kg body weight: Yes, on a weekly basis
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

HAEMATOLOGY: Yes
At termination, all rats were bled by cardiac puncture and samples were collected. Parameters determined: Hemoglobin, red cell count, haematocrit, mean cell volume, mean cell haemoglobin, mean cell haemoglobin concentration, platelet count, white blood cell count, neutrophil count, lymphocyte count, monocyte count, eosinophil count, prothrombin time and kaolin-cephalin time

CLINICAL CHEMISTRY: Yes
At termination, all rats were bled by cardiac puncture and samples were collected. Parameters determined: Albumin, total protein, cholesterol, triglycerides, urea, creatinine, glucose, total bilirubin and alkaline phosphatase, plasma gamma-glutamyl transferase, plasma alanine aminotransferase, plasma aspartate aminotransferase, plasma creatine kinase, plasma sodium, plasma potassium, plasma chloride, plasma calcium and plasma phosphorus

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: on Days 8, 15, 22, 29
- Dose groups that were examined: All
- Battery of functions tested: sensory activity / grip strength

Sacrifice and pathology:

GROSS PATHOLOGY: Yes

HISTOPATHOLOGY: Yes (adrenals, aorta, bladder, bone and bone marrow (femur), brain, caecum, colon, cervical lymph node, cervix, colon, duodenum, epididymis, eye and harderian gland, heart, ileum, jejunum, kidney, liver, lungs, mammary gland, mesenteric lymph node, nasal passages, oesophagus, oral cavity, ovaries, pancreas, parathyroid glad, pituary gland, prostate gland, rectum, salivary glands, sciatic nerve, seminal vesicles, skin, spinal chord, spleen, sternum, stomach, testes, thymus, thyroid gland, trachea, uterus, voluntary muscle)

Statistics:

Bodyweights were considered by analysis of covariance on initial body weight, separately for males and females.
Time to tail flick and fore and hindlimb grip strength at weeks 2, 3, 4 and 5 were considered by analysis of variance, separately for both sexes.
Haematological and clinical blood parameters were considered by analysis of variance.
Organ weights were considered by analysis of variance and covariance on final body weight separately for both sexes.

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

reduction in haemoglobin and haematocrit (males), reductions in haemoglobin, haematocrit and in white blood cell count (females).

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

minor reductions in plasma cholesterol, triglyceride, total protein levels and plasma alanine transferase activities in males

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

increased kidney weights (males), slightly increased kidney weights (females), increased liver weights (males/females) in 5000 and 12500 ppm groups

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

kidney: increased tubular hyaline droplet formation, tubular basophilia, granular cast formation (males). liver: minimal hepatocyte hypertrophy in 4/5 male rats

Histopathological findings: neoplastic:

no effects observed

Details on results:

DIET ANALYSIS:
All diets prepared were found to be within 4% of the target concentration. The homogeneity of the test material in the diet, determined at 1000 and 12500 ppm inclusion levels was within 2 % of the overall mean concentration for both levels. Chemical stability of the test material, assessed at the 1000 and 12500 ppm inclusion levels stored at room temperature or at -20 °C was satisfactory over the period of use.
Dose rates (based on nominal dietary levels) were highest at the start of the study and declined rapidly during the period of rapid growth to week 4.

MORTALITY
There were no mortalities.

FUNCTIONAL OBSERVATION BATTERY
A slightly reduced splay reflex was observed in one female of the 1000 ppm group (on days 29 and 30), in one male of the 5000 ppm group (on day 29) and in one male of the 12.500 ppm group (on day 29). As isolated observations, these were considered to be incidental.
There were no differences in time to tail flick in either sex which could be attributed to treatment. The statistically significant increase in time to response observed on day 22 for males (5000 ppm) and day 8 for females (1000 ppm) were considered to be incidental to treatment in the absence of similar changes at higher dose levels.
There was no evidence of any treatment related effects on forelimb or hindlimb grip strength.
Any other statistically significant changes were considered spurious and unrelated to treatment with the test material.

BODY WEIGHT AND WEIGHT GAIN
There were no statistically significant effects on body weight and all final bodyweights were within 3% of the respective controls, after adjusting for initial weight differences.

FOOD CONSUMPTION
Food consumption in all treated groups remained similar to, or exceeded that, of the respective control group throughout the study.

HAEMATOLOGY
There were statistically significant reductions in haemoglobin and haematocrit at 12.500 ppm in male rats. Statistically significant reductions in haemoglobin and haematocrit were seen in females at 1000 and 5000 ppm and in white blood cell count at 1000 ppm. In the absence of a coherent dose-response relationship, these differences were considered incidental to treatment.
Any other statistically significant changes were considered spurious and unrelated to treatment with the test material.

CLINICAL CHEMISTRY
There were minor reductions in plasma cholesterol, triglyceride and total protein levels and plasma alanine transferase activities in males at 12500 ppm compared to controls. Any other statistically significant changes were considered spurious and unrelated to treatment with the test material.
ORGAN WEIGHTS
Kidney weights adjusted for body weight were statistically significant increased in males at 5000 and 12500 ppm. All the females in the treatment groups had slightly raised kidney weights compared to control, but none achieved statistical significance, and there was no evidence of a coherent dose response relationship.
Liver weights adjusted for body weight were statistically significant increased in both sexes at 12500 ppm and in males at 5000 ppm.
Any other statistically significant changes were considered spurious and unrelated to treatment with the test material.

PATHOLOGY:
Macroscopic findings:
No treatment-related macroscopic findings were apparent at the end of the study.
HISTOPATHOLOGY:
Microscopic findings:
Treatment related findings were present in the kidney of male rats from all dose groups. In the 5000 and 12500 ppm dose group these comprised increased tubular hyaline droplet formation and tubular basophilia in all animals, and granular cast formation in four of the 5000 ppm animals and all of the 12500 ppm animals; the latter occurring at the cortico-medullary injection. In the 1000 ppm group, increased renal hyaline droplet formation and/or tubular basophilia were seen, but not granular cast formation.
In the liver, there was minimal hepatocyte hypertrophy in 4/5 male rats in the 12500 ppm group.

The increased kidney weights and microscopic findings of renal tubular basophilia, granular cast formation and increased hyaline droplet formation present in male rats at 5000 and 12.500 ppm are clearly treatment related. These findings are consistent with the well characterized light hydrocarbon nephropathy described for male rats, following to a variety of chemicals including light hydrocarbons such as unleaded gasoline and trimethyl pentane. The characteristics include an increased accumulation of hyaline droplets in male rat kidneys, the main constituent of which is alpha 2µ-globulin (Alden et al. Adv. Modern Environ Toxicol 7: 107-120 (1984); Stonard et al. Renal Heterogeneity and Target Cell Toxicity. Bach PH and Lock EA Eds, John Wiley and Sons (1985)). It is widely accepted that this phenomenon is specific to male rat and as such appears to have no relevance for man (Swenberg et al. Toxicol and App. Pharmacol. 97: 35-46 (1989)).

Dose descriptor:

NOAEL

Effect level:

1 613 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: No effects observed in female rats

Dose descriptor:

NOAEL

Effect level:

1 450 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: corresponding to 12500 ppm

Critical effects observed:

not specified

Cross-reference 2

Reason / purpose for cross-reference:

assessment report

Reference

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Reason / purpose for cross-reference:

assessment report

Reason / purpose for cross-reference:

assessment report

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

GLP compliance:

not specified

Species:

rat

Sex:

male/female

Route of administration:

oral: feed

Dose descriptor:

NOAEL

Effect level:

12 500 ppm

Based on:

test mat.

Sex:

female

Basis for effect level:

other: no effects observed

Dose descriptor:

NOAEL

Effect level:

1 613 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: no effects observed

Dose descriptor:

NOAEL

Effect level:

12 500 ppm

Based on:

test mat.

Sex:

male

Basis for effect level:

other: no effects observed

Dose descriptor:

NOAEL

Effect level:

1 450 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: no effects observed

Critical effects observed:

no

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Deviations:

yes

Remarks:

limited data on test material available

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

189120-64-7

Cas Number:

189120-64-7

IUPAC Name:

189120-64-7

Specific details on test material used for the study:

- Name of test material (as cited in study report): MRD-99-429
- Physical state: pale yellow liquid
- Analytical purity: no data
- Expiration date of the lot/batch: 09/2004
- Storage condition of test material: at room temperature

Test animals

Species:

rat

Strain:

other: Cr:CD BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc., New York, USA
- Age at study initiation: ca. 8 weeks
- Weight at study initiation: 246-287 g (males) and 178-206 g (females)
- Housing: animals were housed individually in suspended stainless steel and wire mesh cages with absorbent paper
- Diet: Certified Rodent Diet #5002 (PMI Feeds, Inc., Richmond, USA), ad libitum
- Water: water from an automatic watering system (ExxonMobil Research and Engineering Potable Water System), ad libitum
- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): ca. 19-22
- Humidity (%): 30-70
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 01 Mar 2000 To: 30 Mar 2000

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

peanut oil

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: dosing solutions were prepared weekly by dissolving appropriate amounts of the test substance in peanut oil yielding a final concentration of 2, 6 and 20% (w/v) for dose levels of 100, 300 and 1000 mg/kg bw/day, respectively.

VEHICLE
- Justification for use and choice of vehicle (if other than water): the test substance was soluble in the carrier at the concentrations required for this study
- Concentration in vehicle: 2, 6 and 20% (w/v) corresponding to 100, 300 and 1000 mg/kg bw/day, respectively
- Amount of vehicle (if gavage): 5 mL/kg bw
- Lot/batch no.: 29H0162

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

ANALYSIS METHOD
Analysis for the stability, uniformity, and concentration of the test and control material solutions were performed by the testing laboratory. Analysis for stability and uniformity was initiated prior to or concomitant with the experimental start. Concentration analysis were performed for the Week 1 and 4 mixtures. Samples of dosing solutions ranging from 1 and 50% (w/v) in peanut oil were diluted in ethyl acetate and analysed for uniformity, stability and concentrations using Gas Chromatography with Flame Ionization Detection (GC/FID).

ANALYSIS RESULTS
Satisfactory uniformity was observed. All values were within ± 14% of the nominal value with a maximum relative standard deviation of 2.4%. Stability data indicated that the test substance in peanut oil was stable for at least 15 days at room temperature. Concentration verification analyses indicated that the test substance concentrations were within 9% of the nominal values.

Duration of treatment / exposure:

28 days

Frequency of treatment:

daily, 7 days/week

Doses / concentrations

Remarks:

Doses / Concentrations:
100, 300 and 1000 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: based on a preliminary range-finding study, which revealed clinical signs of toxicity and mortality in treated animals, the high dose was set at 1000 mg/kg bw/day. The other dose levels (mid and low) were set at approximately half-log intervals from the high dose.

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: the animals were examined for viability twice daily. Clinical signs of toxicity as well as the nature, onset, severity, and duration of these effects were observed daily.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: once during Weeks 1, 2, and 3, all animals were observed in a standard arena for changes in skin, fur, eyes, mucous membranes, occurrence of secretions and excretions, and autonomic activity (e.g. lacrimation, piloerection, pupil size, and unusual respiratory pattern). Changes in gait, posture, and response to handling as well as the presence of clonic or tonic movements, stereotypies or unusual behaviour also were recorded.

BODY WEIGHT: Yes
- Time schedule for examinations: body weights were determined prior to initiation of dosing, on the day of treatment (Day 0), on Days 7, 14, 21, and 27 as well as on the day of sacrifice.

FOOD CONSUMPTION:
- Food consumption for each animal determined: Yes

HAEMATOLOGY: Yes
- Time schedule for collection of blood: on Day 28
- Anaesthetic used for blood collection: Yes (halothane)
- Animals fasted: Yes, overnight
- How many animals: all
- Parameters checked: haematocrit, haemoglobin, erythrocyte count, leukocyte count (total and differential, platelet count, reticulocyte count, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, prothrombin time and thromboplastin time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: on Day 28
- Animals fasted: Yes, overnight
- How many animals: all
- Parameters checked: albumin, urea nitrogen, calcium, creatinine, electrolytes (Na+, Cl-, K+), glucose, phosphorus, gamma glutamyl transpeptidase, serum alanine aminotransferase, serum aspartate aminotransferase, serum alkaline phosphatase, total protein, total bilirubin, cholesterol, triglycerides

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: prior to dosing and during Week 4
- Dose groups that were examined: all
- Battery of functions tested: sensory activity / grip strength / motor activity, other: functional observational battery

Sacrifice and pathology:

GROSS PATHOLOGY: Yes (see Table 1 under “Any other information of materials and methods incl. tables")
HISTOPATHOLOGY: Yes (see Table 1 under “Any other information of materials and methods incl. tables")

Other examinations:

Organ weights of liver, kidneys, adrenals, testes, brain, heart, spleen, thymus and epididymides were determined.

Statistics:

Statistical evaluation of equality of means was done by an appropriate one-way analysis of variance and a test for ordered response in the dose groups. First, Bartlett's Test was performed to determine if the dose groups have equal variance. If the variances were equal, the testing was done using parametric methods, otherwise nonparametric techniques were used. For the parametric procedures, a standard one-way ANOVA using the F distribution to assess significance was used. If significant differences among the means were indicated, Dunnett's Test was used to determine which treatment groups differed significantly from control. In addition to the ANOVA, a standard regression analysis for linear response in the dose groups was performed. For the nonparametric procedures, the test of equality of means was performed using the Kruskal-Wallis Test. If significant differences among the means were indicated, Dunn's Summed Rank Test was used to determine which treatment groups differed significantly from the control. In addition to the Kruskal-Wallis Test, Jonckheere's Test for monotonic trend in the dose-response was performed. Bartlett's Test for equal variance was conducted at the 1% level of significance. All other tests were conducted at the 5% and 1% level of significance.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

300 and 1000 mg/kg bw/day (f): statistically significant decrease in mean body weight gain between Day 7 and Day 14 (non-adverse)

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

1000 mg/kg bw/day: statistically significant decrease in mean corpuscular haemoglobin concentration (f, non-adverse); statistically significant decrease in neutrophils and statistically significant increase in lymphocytes (m, non-adverse)

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

1000 mg/kg bw/day (m): decrease in alanine aminotransferase; 300 and 1000 mg/kg bw/day (f): decreases in blood urea nitrogen and increases in sodium and calcium levels; 300 mg/kg bw/day (f): increase in cholesterol; non-adverse

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

300 and 1000 mg/kg bw /day (f): statistically significant increases in the mean relative liver weight (non-adverse)

Gross pathological findings:

no effects observed

Neuropathological findings:

effects observed, treatment-related

Description (incidence and severity):

300 and 1000 mg/kg bw/day (m): increased amount of hyaline droplets in the proximal cortical tubular epithelium (non-adverse)

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY
No mortalities and no treatment-related signs of toxicity occurred during the study period. There were single or very low incidences of dental abnormalities, dried red ocular discharge, and red material seen around the nose observed in one or more groups, including controls.

BODY WEIGHT AND WEIGHT GAIN
There were no biologically or statistically significant differences in mean body weight between treated and control animals. There was a statistically significant decrease in mean body weight gain between Day 7 and Day 14 in females treated with 300 and 1000 mg/kg bw/day. Since this change was not accompanied by any statistically significant difference in the mean body weights of females, it was not considered biologically significant.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
There were no statistically significant or biologically significant differences in mean food consumption during the study.

HAEMATOLOGY
A slight, statistically significant decrease in the mean corpuscular haemoglobin concentration was observed in females receiving 1000 mg/kg bw/day. However, this decrease was very small (-2%) and the parameters (haemoglobin and haematocrit) that are used to calculate this parameter were not statistically different from the control values. Thus, the change in mean corpuscular haemoglobin concentration was not considered biologically significant. In males, a statistically significant decrease in the neutrophils and a statistically significant increase in lymphocytes were noted at 1000 mg/kg bw/day. These changes appeared to be treatment-related, but due to the lack of any corresponding findings, these changes were not considered biologically significant.

CLINICAL CHEMISTRY
In males, a statistically significant decrease in alanine aminotransferase was observed at 1000 mg/kg bw/day compared to control. However, this alteration was not attributable to any toxic effects and thus considered to be of no biological relevance. In females, a statistically significant decrease in mean blood urea nitrogen and statistically significant increases in mean sodium and mean calcium were noted in the 300 and 1000 mg/kg bw/day groups. However, the biological significance of these differences was questionable. Additionally, there was a statistically significant increase in mean cholesterol in females receiving 300 mg/kg bw/day. This difference was not considered biologically significant due to the lack of a dose response relationship.

NEUROBEHAVIOUR
There were no statistically significant differences in the functional observational battery parameters between treated and control animals. There were no statistically significant differences between treated and control groups in motor activity.

ORGAN WEIGHTS
There were statistically significant increases in the mean relative liver weight in females treated with 300 and 1000 mg/kg bw/day (11 and 18%, respectively) when compared to the controls. Since the increase in mean relative liver weight was not correlated with any microscopic effects, it was not considered biologically significant.

GROSS PATHOLOGY
No treatment-related findings were observed at necropsy. Incidental findings included a single incidence of kinked tail in one male treated with 100 mg/kg bw/day and two instances of discoloured thymus in one male and one female of the control.

HISTOPATHOLOGY: NON-NEOPLASTIC
Microscopic examination did not reveal test substance-related microscopic changes in males treated at 100 mg/kg/day or in females treated with up to 1000 mg/kg bw/day. In contrast, an increased amount of hyaline droplets in the proximal cortical tubular epithelium were confirmed microscopically in the cytoplasm of the renal cortical tubular epithelial cells in male rats treated with 300 and 1000 mg/kg bw/day, respectively. this phenomenon is widely accepted to be specific to the male rat and as such is considered to have no relevance to manTherefore

Effect levels

Dose descriptor:

NOAEL

Effect level:

> 1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: overall effects

Target system / organ toxicity

Critical effects observed:

not specified