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Toxicological information

Repeated dose toxicity: oral

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Administrative data

Endpoint:
short-term repeated dose toxicity: oral
Remarks:
combined repeated dose and reproduction / developmental screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2014-09-25 to 2015-05-15
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 guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
Version / remarks:
1996
Deviations:
no
Qualifier:
according to guideline
Guideline:
other: EPA Health Effects Test Guidelines, OPPTS 870.3650 Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test, July 2000
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Limit test:
no

Test material

Constituent 1
Reference substance name:
(3E)-12-[(2-{2-[(E)-[2,2-dimethyl-3-(morpholin-4-yl)propylidene]amino]propoxy}propoxy)methyl]-12-ethyl-2,2,5,8-tetramethyl-1-(morpholin-4-yl)-7,10,14-trioxa-4-azaheptadec-3-en-16-ol; 4-[(3E,20E)-12-[(2-{2-[(E)-[2,2-dimethyl-3-(morpholin-4-yl)propylidene]amino]propoxy}propoxy)methyl]-12-ethyl-2,2,5,8,16,19,22,22-octamethyl-23-(morpholin-4-yl)-7,10,14,17-tetraoxa-4,20-diazatricosa-3,20-dien-1-yl]morpholine; 4-[(3E,20E)-12-ethyl-2,2,5,8,16,19,22,22-octamethyl-23-(morpholin-4-yl)-7,10,14,17-tetraoxa-4,20-diazatricosa-3,20-dien-1-yl]morpholine
EC Number:
700-879-7
Cas Number:
1379822-00-0
Molecular formula:
NA: UVCB substance
IUPAC Name:
(3E)-12-[(2-{2-[(E)-[2,2-dimethyl-3-(morpholin-4-yl)propylidene]amino]propoxy}propoxy)methyl]-12-ethyl-2,2,5,8-tetramethyl-1-(morpholin-4-yl)-7,10,14-trioxa-4-azaheptadec-3-en-16-ol; 4-[(3E,20E)-12-[(2-{2-[(E)-[2,2-dimethyl-3-(morpholin-4-yl)propylidene]amino]propoxy}propoxy)methyl]-12-ethyl-2,2,5,8,16,19,22,22-octamethyl-23-(morpholin-4-yl)-7,10,14,17-tetraoxa-4,20-diazatricosa-3,20-dien-1-yl]morpholine; 4-[(3E,20E)-12-ethyl-2,2,5,8,16,19,22,22-octamethyl-23-(morpholin-4-yl)-7,10,14,17-tetraoxa-4,20-diazatricosa-3,20-dien-1-yl]morpholine
Test material form:
liquid

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Toxi-Coop Zrt. Cserkesz u. 90. H-1103 Budapest Hungary
- Age at study initiation: Males: 14 - 15 weeks old, Females: 14 - 15 weeks old
- Weight at study initiation: Males: 352 - 422 g, Females: 204 - 252 g, the weight variation in animals involved at the starting point of the study did not exceed ± 20% of the mean group weight of each sex
- Housing: Before mating: 2 animals of the same sex/ cage Mating hours: 1 male and 1 female / cage. Pregnant females were housed individually. Males after mating: 2 animals / cage
- Diet: Ssniff® SM R/M-Z+H "Autoclavable complete feed for rats and mice – breeding and maintenance" produced by ssniff Spezialdiäten GmbH, D-59494 Soest, Germany ad libitum
- Water: Tap water from municipal supply, as for human consumption from a 500 mL bottle ad libitum
- Acclimation period: 34 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 °C
- Humidity (%): 30 - 70
- Air changes (per hr): 10-15 air changes/hour by central air-condition system
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
polyethylene glycol
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS: Formulations were prepared in the formulation laboratory of the Test Facility daily. Analysis of formulations (checking of concentration and homogeneity) was performed in the Analytical Laboratory of Test Facility two times during the study.

VEHICLE
- Justification for use and choice of vehicle: The test item is not soluble in water therefore PEG 400 was used for preparing formulations appropriate for oral administration. PEG 400 was shown to be a suitable vehicle to facilitate formulation analysis for the test item. The same vehicle was used previously for very similar substances with good results. Sufficient historical control data with this vehicle are available.
- Concentration in vehicle: The test item was formulated in the vehicle in concentrations of 200, 60 and 20 mg/mL.
- Lot/batch no.: 14B110500
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Checking of concentration of test item in formulations prepared in Polyethylene glycol 400. The test item was analyzed using HPLC with MS detection based on the peaks of oligomers of main constituent.

Analysis of formulations (checking of concentration and homogeneity) was performed in the Analytical Laboratory of Test Facility two times during the study. Five samples (5 mL, each) were taken from different places from each concentration (Groups 2, 3 and 4) and all samples were measured. Similarly, five samples (5 mL, each) were taken from the vehicle (Group 1), from different places, and analyzed. Date of sampling and analysis: October 01 and November 05, 2014.

Apparatus:

UHPLC system: Flexar LC Solvent Manager
No.: 260S12071605F
Flexar FX UHPLC Autosampler
No.: 293H2080102B
Flexar FX-10 UHPLC Pump A
No.: 291S12071663FX
Flexar Column Oven
No.: OVPF120715458

Mass spectrometer: AB SCIEX QTRAP 5500
No.: AU29511207

Balances: BL 120S Sartorius, No.: 15307011
AB54-S Mettler-Toledo, No.: 1122092721
BP 210D Sartorius, No.: 60602907

Vortex: Reamix 2789, No.: 730170

Ultrasonic bath: Branson 3210, No.: A700343D

HPLC Conditions

Column: Purospher STAR RP-18 endcapped 30-2 mm, 3 μm; No.: 720093
Mobil Phase: 1 mM Ammonium Formate in Methanol
Flow Rate: 0.6 mL/min
Injection volume: 5 μL
Run time: 5 minutes

MS Conditions

Scan Type: Q1 Multiple Ions (Q1 MS)
Polarity: positive
Ion Source: Heated Nebulizer
Ionisation mode Atmospheric Pressure Chemical Ionization (APCI)
Detector: Q1 Mass (Da): 824 for (x+y+z) = 4 oligomer Dwell: 200 msec
Q1 Mass (Da): 882 for (x+y+z) = 5 oligomer Dwell: 200 msec
Q1 Mass (Da): 940 for (x+y+z) = 6 oligomer Dwell: 200 msec
Parameter Table: Curtain Gas (CUR): 30 Temperature (TEM): 500 Nebulizer gas (GS1): 35 Heater Gas (GS2): 25 Nebulizer Current (NC): 4 DP (Declustering Potential): 150 EP (Entrance Potential): 10
Run time: 5 minutes
Duration of treatment / exposure:
Male animals were dosed for 43 days, female animals were dosed for 14 days pre-mating, during mating period, through gestation and up to lactation days 3-6 (altogether for 43 - 58 days depending on day of mating). The day of delivery (viz. when parturition was complete) was defined as day 0 post-partum.
Frequency of treatment:
Daily
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day (actual dose received)
Dose / conc.:
100 mg/kg bw/day (actual dose received)
Dose / conc.:
300 mg/kg bw/day (actual dose received)
Dose / conc.:
1 000 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
12 males and 12 females per group
Control animals:
yes
Details on study design:
The dose setting with 1000, 300 and 100 mg/kg bw/day doses based on findings obtained in a previous repeated dose oral gavage toxicity study with Sika Hardener MTJ in rats and after consultation of the Sponsor (Supporting study, Toxi-Coop study no. 644-400-0049). In general, the doses were selected with the aim of inducing toxic effects but no death or suffering at the highest dose and a NOAEL at the lowest dose.
Positive control:
none

Examinations

Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Once, prior to the first exposure and once weekly thereafter.

BODY WEIGHT: Yes
- Time schedule for examinations: Males: First day of dosing, weekly thereafter and on the day of necropsy. Females: Weighed on the first day of dosing, then weekly on gestation days 0, 7, 14 and 21 and on post-partum day 0 and post-partum day 4. Additionally, female animals were weighed on gestational days 10 and 17 in order to give accurate treatment volumes, but these data were not evaluated statistically. Body weight was measured on day of necropsy for animals subjected to organ weighing (all male animals and females selected for further examinations).

FOOD CONSUMPTION AND COMPOUND INTAKE:
- The food consumption was determined weekly by reweighing the non-consumed diet with an accuracy of 1 g during the treatment period except mating days (pre-mating and post mating for male animals and non-pregnant females, during pre-mating, gestation days 0, 7, 14 and 21, lactation days 0 and 4)

HAEMATOLOGY: Yes
- Time schedule for collection of blood: One day after the last treatment
- Anaesthetic used for blood collection: No data
- Animals fasted: Yes
- How many animals: 5 males and 5 females
- Parameters checked in table 1 were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: one day after the last treatment
- Animals fasted: Yes
- How many animals: 5 males and 5 females from each group
- Parameters checked in table 2 were examined.
Sacrifice and pathology:
GROSS PATHOLOGY: Yes (see table 3)
HISTOPATHOLOGY: Yes: Detailed histological examinations were performed on the ovaries, uterus, vagina, pituitary, testes and epididymides of all animals in the control and high dose groups.
Detailed histological examination of the ovaries covered the follicular, luteal, and interstitial compartments of the ovary, as well as the epithelial capsule and ovarian stroma.
For testes and epididymides, examinations were performed with special emphasis on stages of spermatogenesis in the male gonads and histopathology of interstitial testicular cell structure.
Full histopathology examinations were performed on the preserved organs and tissues of the randomly selected animals (n=5 animals/ sex/ group) in the control and high dose groups. Examinations of the kidneys were extended to animals of the mid dose group because treatment-related changes were observed in the kidneys in the high dose group, following consultation with the Sponsor’s scientific monitor.
Other examinations:
At the time of termination, fasted body weight (all male animals) and weight of the testes, epididymides of all parental animals were determined with an accuracy of 0.01 g. In addition, for five males and females randomly selected from each group, adrenals, brain, heart, kidneys, liver, spleen and thymus were weighed. Fasted body weight of these female animals was determined, too. Paired organs were weighed together; absolute organ weight was reported. Relative organ weight (to body and brain weight) were calculated and reported.
Statistics:
The statistical evaluation of appropriate data were performed with the statistical program package SPSS PC+4.0. The homogeneity of variance between groups was checked by Bartlett’s homogeneity of variance test. Where no significant heterogeneity was detected a one-way analysis of variance (ANOVA) was carried out. If the obtained result was significant Duncan Multiple Range test was used to access the significance of inter-group differences. Getting significant result at Bartlett’s test the Kruskal-Wallis analysis of variance was used and the inter-group comparisons were performed using Mann-Whitney U-test. Chi2 test was performed if feasible. The frequency of clinical signs, pathology and histopathology findings were calculated. Results were evaluated in comparison with values of control group (i.e. control value).

Results and discussion

Results of examinations

Clinical signs:
no effects observed
Mortality:
mortality observed, treatment-related
Description (incidence):
Test item related death occurred at 1000 mg/kg bw/day (3/12 males and 4/12 females). Three male animals died on Days 26, 34 or 40. Three pregnant animals and one dam were found dead on gestation days 21, 22 or on lactation day 3. There were no preceding clinical signs in any of these animals.
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
The body weight development was slightly reduced at 1000 mg/kg bw/day (male and female). The body weight gain of male animals at 1000 mg/kg bw/day was reduced during the first two weeks (pre-mating period) of the study. This resulted in a statistically significant difference in the total body weight gain and in the mean body weight compared to the control from Day 13 up to the end of the study. As these changes was associated with a slightly less mean body weight of these animals (approximately -5 % or -6%), this alteration therefore was not considered to be toxicologically significant.
The body weight gain exceeded that of the control group in male animals at 300 and 100 mg/kg bw/day between Days 34 and 41. However, these changes did not cause relevant or significant changes in the mean body weight of these groups.
The body weight development was similar to that of the controls for the female animals administered with 1000, 300 or 100 mg/kg bw/day of Sika Hardener MTJ during the pre-mating and gestation periods. Slight statistical significance was only detected for the higher mean body weight gain of female animals at 300 mg/kg bw/day between Days 0 and 7, which had no influence on the mean body weight and was judged to be indicative of biological variation and not related to the test item. The mean body weight of dams at 1000 mg/kg bw/day was slightly but statistically significantly less than in the control group on lactation days 0 and 4.
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Description (incidence and severity):
A test item related influence on the mean daily food consumption was observed in male and female animals at 1000 mg/kg bw/day during the first week of premating period and in female animals at 1000 mg/kg bw/day during the course of gestation period and between lactation days 0 and 4. The mean daily food consumption was significantly lower with respect to control group for these groups. This finding coincided with the reduction of body weight of male animals on week 1 and of dams during the lactation period as described above.
Compared to the control animals, statistical significance was also observed in the slightly higher mean food consumption of male animals at 300 mg/kg bw/day between Days 20 and 27 as well as at 100 mg/kg bw/day between Days 20 and 27 and between Days 34 and 41. However these differences with respect to the control were with small degree and were considered to be without any toxicological relevance.
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
no effects observed
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
The absolute and relative weights of examined organs did not demonstrate any test item related adverse alterations. There were slight increases in the absolute and/or relative weights of the kidneys at 1000 mg/kg bw/day (males and females randomly selected) However, the values were within the historical control ranges.
Statistical significances were observed at the reduced mean fasted body weight and brain weight, at the higher mean liver and kidneys weight (both relative to body weight), at the higher mean kidneys and adrenal glands weights (both relative to brain weight) with respect to the control in male animals at 1000 mg/kg bw/day. The mean weights of kidneys, testes and adrenal glands (absolute, each), mean liver weight relative to body weight, and the mean kidneys and testes weights (both relative to brain weight) exceeded that of the control group in male animals at 300 mg/kg bw/day. Other statistically significant changes in low dose male animals were the higher mean testes and adrenal weights.
In the female animals selected for additional toxicological examinations at 1000 mg/kg bw/day, statistically significant differences were observed at the mean fasted body weight, at the mean kidneys and thymus weights (both absolute and relative to the body and brain weights) and at the mean brain weight relative to body weight. A statistically significant difference with respect to the control was detected at the slightly lower mean adrenal gland weight relative to body and brain weight in female animals at 300 mg/kg bw/day.
The slight changes in weights of adrenal glands, thymus, testes, brain, and liver were not considered to be toxicologically relevant due to the small degree and in the lack of associated histopathological alterations.
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
Sika Hardener MTJ caused hyaline droplet nephropathy and tubular necrosis in the kidneys of prematurely died animals, and hyaline droplet nephropathy in the kidneys of male animals at 1000 mg/kg bw/day.
Histopathological examination revealed hyaline droplet nephropathy and tubular necrosis in the kidneys and congestion and alveolar edema in the lungs in all dead animals (3/3 male and 4/4 female). These lesions were considered as related to the application of the high dose of the test item. In one of the prematurely died female animal hemorrhage was detected in the uterus, which was considered as individual disorder after the delivery.
Hyaline droplet nephropathy was also observed in the kidneys of male animals (5/5) at 1000 mg/kg bw/day randomly selected for histopathological examination. Hyaline droplet nephropathy and “hydrocarbon nephropathy” are terms describe a spectrum of morphologic changes in the kidneys of male rats induced by a variety of structurally related and unrelated compounds. There is abnormal accumulation of a-2µ-globulin phagolysosomes of tubular epithelium. One proposed mechanism suggests that the chemical or a metabolite binds with the a-2µ-globulin or alters the structure so that the tubular cell lysosomal enzymes cannot degrade the protein complex. Other proposed mechanisms include a direct cytotoxic effect. It is unlikely that the various chemicals associated with hyaline droplet nephropathy in the male rat act by the same mechanism. Some chemicals which produce hyaline droplet nephropathy in male rats produce renal toxicity (unassociated with a-2µ-globulin) in female rats, whereas other chemicals produce no effects in the kidney of female rats. Marked tubular necrosis and regeneration of tubular epithelium are sometimes seen.
No hyaline droplet nephropathy or tubular necrosis in the kidneys was seen in the surviving female animals (5/5) of the high dose group or in male (5/5) and female animals (5/5) of the mid dose group (300 mg/kg bw/day) randomly selected for histopathological examinations.
Alveolar emphysema in minimal or mild degree was observed in the lungs of male (1/5 control and 2/5 at 1000 mg/kg bw/day) and female (2/5 control) animals. Pulmonary emphysema occurred sporadically and was considered to be consequence of hypoxia, dyspnea and circulatory disturbance developed during exsanguination.
Hyperplasia of bronchus associated lymphoid tissue (BALT) in some control and test item treated animals (1/5 male and 1/5 female control; 1/5 male and 1/5 female at 1000 mg/kg bw/day) is a physiological phenomenon.
Dilatation of the uterine horns in non-pregnant female animal (1/12) at 1000 mg/kg bw/day is a slight neuro-hormonal phenomenon in connection with the sexual function – estrus phase – of the inner genital organs.
Histopathological findings: neoplastic:
no effects observed
Details on results:
The investigated organs of reproductive system (testes, epididymides), were histologically normal and characteristic on the sexually mature organism in all examined male animals at 1000 mg/kg bw/day (12/12) and in the control group (12/12 for both groups). The various spermatogenic cells (the spermatogonia, the spermatocytes, the spermatids and spermatozoa), representing different phases in the development and differentiation of the spermatozoons and the interstitial cells were the same in quantity and morphologically in the testes of investigated control and treated animals. The histological picture of epididymides and pituitary was normal in all cases as well.
The ovaries had a normal structure characteristic on the species, age and phase of the active sexual cycle in all investigated female animals (dams and non-pregnant female) in the control and test item treated groups (12/12 for both groups). The cortex contained primary, secondary and tertiary follicles and corpora lutea, indicating the active maturation of oocytes and ovulation. The epithelial capsule and ovarian stroma was normal in all cases as well. The uterus, cervix, vagina and pituitary had a normal structure in accordance with the phase of sexual cycle in the investigated animals.
No morphological evidence of acute or subacute injury (degeneration, inflammation, necrosis etc.) of the digestive system, cardiovascular system, immune system, hematopoietic system, the skeleton, the muscular system, the male reproductive system or the central, or peripheral nervous system was detected.
No difference was observed by light microscopic investigation regarding the quantity or cyto-morphology of lymphoid cells in the spleen, thymus, lymph nodes, Peyer’s patches and of the myeloid and erythroid blast cells in the bone marrow (in the sternum and femur) between the test items treated and control animals.
The structure and the cell morphology of the endocrine glands was the same in the control and treated animals.

Effect levels

Key result
Dose descriptor:
NOAEL
Effect level:
300 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Systemic toxicity of male and female rats

Target system / organ toxicity

Key result
Critical effects observed:
not specified
Lowest effective dose / conc.:
300 mg/kg bw/day (actual dose received)
System:
urinary
Organ:
kidney

Applicant's summary and conclusion

Conclusions:
Under the conditions of the present study, Sika Hardener MTJ administered orally (by gavage) at 1000 mg/kg bw/day caused premature death and hyaline droplet nephropathy and tubular necrosis in the kidneys in male (3/12) and female (4/12) Hsd.Brl.Han: Wistar rats.
Slightly reduced body weight development, food consumption, increases in the kidneys weights (males and females) and hyaline droplet nephropathy (males) were observed in surviving animals at 1000 mg/kg bw/day. There was no adverse influence on the reproductive performance (gonad function, mating behavior, conception, pregnancy, parturition) in parental male and female Hsd.Brl.Han: Wistar rats at 1000 mg/kg bw/day.
At 300 and 100 mg/kg bw/day, there were no test item related adverse alterations or impairment of the reproductive performance (gonad function, mating behavior, conception, pregnancy, parturition) in parental male and female animals.
The offspring’s body weight development was slightly depressed at 1000 mg/kg bw/day between postnatal days 0 and 4.

Based on these observations the No Observed Adverse Effect Levels (NOAEL) were determined as follows:

NOAEL for systemic toxicity of male/female rats: 300 mg/kg bw/day
NOAEL for reproductive performance of male/female rats: 1000 mg/kg bw/day
NOAEL for F1 Offspring: 300 mg/kg bw/day
Executive summary:

The purpose of this combined repeated dose toxicity study with the reproduction/developmental toxicity screening test was to obtain initial information on the toxic potential of Sika Hardener MTJ and its possible effects on male and female reproductive performance such as gonadal function, mating behavior, conception, pregnancy, parturition as well as development of the F1 offspring from conception to day 4 post-partum when repeatedly administered orally (by gavage) to parental animals at doses of 1000 mg/kg bw/day, 300 mg/kg bw/day and 100 mg/kg bw/day compared to control animals.

Four groups of Hsd.Brl.Han: Wistar rats (n=12/sex/group) were administered with the test item orally (by gavage) once a day at 0 (vehicle), 1000, 300 and 100 mg/kg bw/day doses corresponding to concentrations of 0, 200, 60 and 20 mg/mL. The application volume was 5 mL/kg bw. Control animals received the vehicle, Polyethylene glycol 400 (PEG 400).

The suitability of the vehicle at the intended concentrations of the test item was analytically verified up front. The concentration of the test item in the dosing formulations was checked two times during the study. Sika Hardener MTJ concentrations in the dosing formulations varied in the acceptable range between 98 % and 108 % of the nominal values confirming the proper dosing.

All animals of the parent (P) generation were dosed prior to mating (14 days) and throughout mating. In addition, males received the test item or vehicle after mating up to the day before the necropsy (altogether for 43 days). Females were additionally exposed through the gestation period and up to lactation days 3 -6, i.e. up to the day before necropsy (altogether for 43-58 days). Observations included mortality, clinical signs, body weight, food consumption, mating, pregnancy and delivery process, as well as development of offspring. Five dams and the male mating partners were randomly selected from each group to examine further signs of toxicity such as functional observations, hematology, clinical chemistry, gross necropsy, organ weighing and histopathology.

The dams were allowed to litter, and rear their offspring up to day 4 post-partum. Litters were weighed and offspring were observed for possible abnormalities and were euthanized on postnatal day 4. All parental animals were subjected to gross pathology just after found dead or one day after the last treatment. Histopathology examination was performed on reproductive organs (testes, epididymides, uterus and ovaries) and pituitary in the control and high dose groups. Additionally, full histopathology was performed on the organs and tissues of parental animals (male and female) selected for general toxicological examinations in the control and high dose groups. The kidneys of male and female animals in the mid dose group selected for general toxicological examinations were processed and evaluated histopathologically due to the renal changes observed in animals of the high dose.

The results were interpreted comparing treatment groups with respect to controls, which were treated concurrently with vehicle (Polyethylene glycol 400) only. Historical control data were also considered.

Mortality

Three male animals, three pregnant females during gestation and one dam during lactation, which were administered with 1000 mg/kg bw/day, were found dead during the course of the study. There were no preceding clinical signs in any of these animals. Histopathological examinations revealed hyaline droplet nephropathy and tubular necrosis in the kidneys, congestion and alveolar edema in the lungs as cause of death in all of these animals. These lesions were considered as related to the application of the high dose of the test item.

Clinical observation

Adverse clinical signs of systemic toxicity related to the test item were not detected at any dose level, neither at the daily nor the detailed weekly clinical observations. The behavior and physical condition of the animals was not impaired at each dose level (1000, 300 or 100 mg/kg bw/day) during the entire treatment period.

Body weight and body weight gain

The body weight development was slightly reduced at 1000 mg/kg bw/day with respect to their controls in male animals considering the whole administration period and in female animals during the lactation period.

Food consumption

The daily mean food consumption was slightly reduced in male and female animals at 1000 mg/kg bw/day during week 1 and in female animals at 1000 mg/kg bw/day during the course of gestation and lactation periods.

Hematology

No test item-related changes were observed in investigated hematology or blood coagulation parameters.

Clinical chemistry

Clinical chemistry examinations did not reveal any adverse changes in the examined parameters.

Necropsy

Specific macroscopic alterations related to the test item were not found at necropsy.

Organ weight

There were no test item related changes in brain, testes and epididymides weights of male animals at any dose level. There were slight increases in the absolute and/or relative weights of the kidneys at 1000 mg/kg bw/day (males and females randomly selected) However, the values were within the historical control ranges.

Histopathology

In the kidneys, hyaline droplet nephropathy and tubular necrosis, in the lungs, congestion and alveolar edema were detected in all prematurely died animals at 1000 mg/kg bw/day.

Hyaline droplet nephropathy was also observed in the kidneys of all examined male animals at 1000 mg/kg bw/day randomly selected for examination. Renal alterations in the form of hyaline droplet nephropathy or tubular necrosis were not detected in the female animals at 1000 mg/kg bw/day or in the male and female animals belonging to the 300 mg/kg bw/day group.

Histopathological examinations did not reveal any test item related changes in male or female genital organs (ovaries, testes and epididymides) or in pituitary in at 1000 mg/kg bw/day.

Reproduction

There were no test item related differences between the control and test item treated groups in delivery data of dams and in the reproductive performance of male and female animals.

Offspring

The offspring’s body weight development was slightly depressed between postnatal days 0 and 4. There was no increased mortality and no adverse clinical or necropsy findings were detected in the offspring terminated as scheduled.

Conclusion

Under the conditions of the present study, Sika Hardener MTJ administered orally (by gavage) at 1000 mg/kg bw/day caused premature death and hyaline droplet nephropathy and tubular necrosis in the kidneys in male (3/12) and female (4/12) Hsd.Brl.Han: Wistar rats.

Slightly reduced body weight development, food consumption, increases in the kidneys weights (males and females) and hyaline droplet nephropathy (males) were observed in surviving animals at 1000 mg/kg bw/day. There was no adverse influence on the reproductive performance (gonad function, mating behavior, conception, pregnancy, parturition) in parental male and female Hsd.Brl.Han: Wistar rats at 1000 mg/kg bw/day.

At 300 and 100 mg/kg bw/day, there were no test item related adverse alterations or impairment of the reproductive performance (gonad function, mating behavior, conception, pregnancy, parturition) in parental male and female animals.

The offspring’s body weight development was slightly depressed at 1000 mg/kg bw/day between postnatal days 0 and 4.

Based on these observations the No Observed Adverse Effect Levels (NOAEL) were determined as follows:

NOAEL for systemic toxicity of male/female rats: 300 mg/kg bw/day

NOAEL for reproductive performance of male/female rats: 1000 mg/kg bw/day

NOAEL for F1 Offspring: 300 mg/kg bw/day