5-Isothiazolecarboxamide, 3,4-dichloro-N-(2-cyanophenyl)-

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 Sep 2004 - 01 Aug 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Version / remarks:

adopted 1998

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.3100 (90-Day Oral Toxicity in Rodents)

Version / remarks:

adopted 1998

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: MAFF in Japan (12-Nousan-No. 8147, 2-1-9, 2000)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

3,4-dichloro-N-(2-cyanophenyl)-1,2-thiazole-5-carboxamide

EC Number:

619-682-1

Cas Number:

224049-04-1

Molecular formula:

C11H5Cl2N3OS

IUPAC Name:

3,4-dichloro-N-(2-cyanophenyl)-1,2-thiazole-5-carboxamide

Constituent 2

Reference substance name:

3,4-dichloro-2'-cyano-1,2-thiazole-5-carboxanilide

IUPAC Name:

3,4-dichloro-2'-cyano-1,2-thiazole-5-carboxanilide

Test animals

Species:

rat

Strain:

other: SPF Wistar Hannover

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Fuji Breeding Center, CLEA Japan, Inc. (Sizuoka, Japan)
- Age at study initiation: 4 weeks old
- Weight at study initiation: males: 60-80 g; females: 50-70 g
- Housing: Animals were housed in wire-mesh stainless steel cages in movable stainless steel racks. Each cage accommodated 6 animals of the same sex before grouping and 2 animals of the same sex after grouping
- Diet: Certified diet MF Mash (Oriental Yeast Co., Ltd., Tokyo, Japan); ad libitum
- Water: Water, which was passed through a rapid filtration unit with a sand filter and an absorption unit with a charcoal filter, and then sterilized with sodium hypochlorite and ultraviolet light, was used as a drinking water
- Acclimation period: 10 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 ± 2
- Humidity (%): 55 ± 15
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

DIET PREPARATION
Preparation of the test diet was performed once prior to initiation of treatment, biweekly (3 preparations) and then once after 4 weeks (1 preparation) during treatment. Overall 5 preparations were made. For each dose level, a required amount of the test substance was mixed with a part of the basal diet in a mortar to provide a premix. The premix was then added to the rest of the basal diet and blended to obtain good homogenity.
A stability test confirmed that the test substance in the diet was stable during storage under dark and cold conditions for 5 weeks.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Homogeneity of the test substance in the diet was checked for each dose level. The coefficient of variation for each dose level was within 3.2% and met the acceptable criteria defined by the laboratory.
The mean concentrations determined on the samples at nominal dose levels of 20, 500, 2500, and 20000 ppm were 20.0, 498.4, 2528.8 and 20067.8 ppm (n=2) respectively, which were 100-101% of the target concentrations and met the acceptable criteria defined by the laboratory (100±10%).
The control diet was confirmed to be free from contaminations with the test substance.

Duration of treatment / exposure:

93 days

Frequency of treatment:

daily

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
20, 500, 2500, 20000 ppm
Basis:
nominal in diet

Doses / concentrations 2

Remarks:

Doses / Concentrations:
1.18, 29.7, 148, 1238 mg/kg bw/day
Basis:
other: males: average test substance intake

Doses / concentrations 3

Remarks:

Doses / Concentrations:
1.39, 35.1, 178, 1398 mg/kg bw/day
Basis:
other: females: average test substance intake

No. of animals per sex per dose:

10

Control animals:

yes, plain diet

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: at least twice a day

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: at least once a day

BODY WEIGHT: Yes
- Time schedule for examinations: Body weights were recorded for all animals at initiation of treatment and once weekly during the treatment period.
- Group mean body weight was calculated at each measurement for each sex. Body weight gain was calculated weekly from the body weight for each dose group of each sex. Overall body weight gain throughout the treatment period was also calculated for each sex.

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption by each cage was measured once weekly during the treatment for a period of 4 consecutive days. The obtained values were divided by the number of animals alive in the cage and the number of days for measurement, indicating the mean daily food consumption per animals in the cage; group mean food consumption (g/rat/day) of each sex was calculated weekly from these data. An average of the group mean food consumption throughout the treatment period was also provided for each sex.
- Group mean test substance intake (mg/kg/day) was calculated weekly for each treated group of each sex according to the following formula:
Group mean test substance intake = (Group mean food consumption [g]) x (Nominal concentration [ppm]) / (Group mean body weight [g])

FOOD EFFICIENCY:
- Group mean food efficiency was calculated for each group of each sex weekly during the treatment period as a ratio (%) of the group mean body weight gain to the group mean food consumption per week. An overall average of the group mean food efficiency throughout the treatment period was also calculated for each sex.

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: during acclimatisation period and in week 13
- Dose groups that were examined: all animals in the acclimatisation period; animals from the control group and from the high dose group in week 13

HAEMATOLOGY: Yes
- Time schedule for collection of blood: week 13
- Anaesthetic used for blood collection: Yes (ether anesthesia)
- Animals fasted: Yes (overnight-fasting before blood collection)
- How many animals: all animals
- Parameters examined: hematocrit (Ht), hemoglobin concentration (Hb), erythrocyte count (RBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), platelet count (PLT), prothrombin time (PT), activated partial thromboplastin time (APTT), total leukocyte count (WBC), differential leukocyte count (lymphocyte (L), Neutrophil (N), Monocyte (M), Eosinophil (E), Basophil (B), large unstained cell (LUC)), reticulocyte count (Retics)

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: week 13
- Anaesthetic used for blood collection: Yes (ether anesthesia)
- Animals fasted: Yes (overnight-fasting before blood collection)
- How many animals: all animals
- Parameters examined: alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGTP), creatinine (Creat), blood urea nitrogen (BUN), total protein (TP), albumin (Alb), globulin (Glob), albumin/globulin ratio (A/G ratio), Glucose (Gluc), total cholesterol (T.Chol), triglyceride (TG), total bilirubin (T. Bil), calcium (Ca), inorganic phosphorus (P), sodium (Na), potassium (K), chloride (Cl)

URINALYSIS: Yes
- Time schedule for collection of urine: week 13
- Metabolism cages used for collection of urine: Yes
- Parameters examined: specific gravity, glucose, bilirubin, ketones, occult blood, pH, protein, urobilinogen, appearance, urine volume, urinary sediments,

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: week 11
- Dose groups that were examined: all animals
- Battery of functions tested: motor activity, grip strength (forelimb and hindlimb), sensory activity

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
The following organs and tissues were removed from all animals at necropsy and fixed in 10% neutral-buffered formalin. The lungs were instilled with formalin through the trachea before fixation. The testes of all males were fixed in FSA solution (Formalin-Sucrose-Acetic acid solution).
Organs examined: brain, pituitary, thyroids (including parathyroids, bilateral), heart, thymus, liver, kidneys (bilateral), spleen, adrenals (bilateral), testes (bilateral), epididymides (bilateral), ovaries (bilateral), uterus

HISTOPATHOLOGY: Yes
Histopathological examinations were performed on the following organs and tissues:
1. Those listed below from all animals in the control group and in the 20000 ppm group.
2. Forestomach and all gross lesions from all animals in the 20, 500 and 2500 ppm groups.
The tissues were embedded in paraffin and stained with hematoxylin and eosin by a routine method. The stained sections were examined microscopically. Sections of the forestomach in the 500 and 2500 ppm groups were prepared in another laboratory (Histo Science Laboratory Co., Ltd.).
Organs/tissues examined: brain (cerebrum, cerebellum, pons, and medulla), spinal cord (cervical, thoracic, and lumbar regions), sciatic nerve (unilateral), pituitary, thymus, thryroids with parathyroids (bilateral), adrenals (bilateral), spleen, bone with bone marrow (sternum; unilateral femur, cervical thoracic, and lumbar vertebrae), knee joint (unilateral), lymph nodes (cervical and mesenteric), heart, aorta, salivary glands (submandibular and sublingual), esophagus, stomach (forestomach and glandular stomach), liver, pancreas, duodenum, jejunum, ileum, cecum, colon, rectum, nasal cavity, pharynx, larynx, trachea, lung, kidneys (bilateral), urinary bladder, testes (bilateral), epididymides (bilateral), prostate, seminal vesicles (bilateral), coagulating glands (bilateral), ovaries (bilateral), uterus (horns and cervix), vagina, eyes (including retina and optic nerve, bilateral), harderian glands (bilateral), skeletal muscle (M. triceps surae, unilateral), skin (lumbodorsal region), mammary gland (adominal region), all gross lessions

Statistics:

Statistical significance of the difference between the control and treated groups was estimated at 5% and 1% levels of probability.
The following tests were used:
- Bartlett´s test for equality
- Dunnett´s multiple comparison test
- Dunnett´s type mean rank sum test
- Fisher´s exact probability test (one-tailed analysis)

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):

statistically significant decrease in body weight gain in males of the 20000 ppm group; considered to be treatment-related in combination with decreased food efficiency

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

effects observed, treatment-related

Description (incidence and severity):

decreased food efficiency in males treated at 20000 ppm; considered to be treatment-related in combination with decreased body weight gain

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

not examined

Ophthalmological findings:

effects observed, treatment-related

Description (incidence and severity):

One female in the 20000 ppm group showed corneal opacity.

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

The observed effects in males and females were considered to be not of toxicological relevance or were not treatment-related as there was no dose response relationship.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Males/females: significant increase in total cholesterol at 20000 and 2500 ppm and in gamma-glutamyl transpeptidase at 20000 ppm; considered to be treatment-related in combination with effect on the liver

Urinalysis findings:

effects observed, treatment-related

Description (incidence and severity):

Females in the 20000 ppm group showed a significant decrease in specific gravity; considered to be treatment-related in combination with effects on kidneys.

Behaviour (functional findings):

effects observed, treatment-related

Description (incidence and severity):

Females showed significant decreases in motor activity in all dose groups. The effects were considered to be incidental as there was no clear dose response relationship.

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Males at 20000 pppm and 2500 ppm: increased liver weights; females at 20000 ppm: increased liver and kidney weights; at 2500 ppm: increased liver weights; the effects were considered to be treatment-related.

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Males/females at 20000 ppm: increased incidence of mucosal epithelial hyperplasia of the limiting ridge of the forestomach (both sexes); pelvic dilatation in the kidney (males); hepatodiaphragmatic nodule in the liver (females).

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY
No animals died or were sacrificed in any treatment group during the treatment period.
General clinical observations: No significant changes in clinical signs were seen in any treatment group.
Detailed clinical observations: In the 2500 ppm group, males and females showed a significant decrease in the score (frequency) of rearing in the open field before initiation of treatment. However, no significant changes were noted in any parameters including rearing during the treatment period. In the 500 ppm group, a significant increase in the score of rearing in the open field was noted in males at Week 6. There were no significant changes in females. No abnormalities were detected in males and females of the 20000 ppm and 20 ppm groups.
The increase in the incidence of rearing males of the 500 ppm group at Week 6 was considered to be incidental as there was no dose response relationship.

BODY WEIGHT AND WEIGHT GAIN
In the 20000 ppm group, body weight gain in males was significantly lower than that of the controls from Weeks 4 to 5. Overall body weight gain in these animals during the treatment period was slightly lower compared to controls (93% of the control group; no statistical significance). Mean body weight at Week 13 was slightly lower compared to controls (95% of the control group; no statistical significance).
In the 20000 ppm group, body weight gain in females was significantly decreased from Weeks 6 to 7. Overall body weight gain and mean body weight at Week 13 of these females were comparable to the control animals (total body weight gain and mean body weight were 98% and 100% of the controls, respectively).
Although significant increases in body weight gain in males of the 2500 ppm group and females of the 20 ppm group from Weeks 11 to 12, mean body weight of these animals were comparable to the control group.
Body weights of males and females in the 500 ppm group were comparable to the control group.

FOOD CONSUMPTION AND COMPOUND INTAKE
There were no marked changes in food consumption in any treatment group.
Test substance intake was calculated from group mean food consumption, group mean body weight and nominal concentration of the test substance in the animal diet.

FOOD EFFICIENCY
Overall mean food efficiency in males of the 20000 ppm group was slightly lower compared to controls (94% of the control). There were no marked changes in food efficiency in females in the 20000 ppm group.
No marked changes in food efficiency in males and females treated at ≤ 2500 ppm were observed.

OPHTHALMOSCOPIC EXAMINATION
One female in the 20000 ppm group showed corneal opacity. There were no treatment-related changes in the high dose group at Week 13.

HAEMATOLOGY
Females (table 1)
Females in the 20000 ppm group showed significant increases in total leukocyte count, lymphocyte count and basophil count. Mean corpuscular volume, mean corpuscular hemoglobin, and prothrombin time in females were significantly decreased.
In the 2500 ppm group, the lymphocyte count was significantly increased.
In the 500 ppm group, females showed a significant increase in the lymphocyte count.
There were no significant changes in females of the 20 ppm group.
As the lymphocyte and total leukocyte counts were within the range of mean ± 2 SD (lymphocyte: 1.33 - 4.49 x 10³/µL; total leukocyte: 2.03 – 5.83 x 10³/µL) of the historical control data (females rats of the same strain and the same age), the findings were considered to have no toxicological significance. Furthermore due to the significant increases in lymphocyte and total leukocyte count, no treatment-related abnormalities were found in general clinical observations and histopathological or hematological parameters.
Also the shortening of the prothrombin time in females of the 20000 ppm group was considered to have no toxicological relevance as the value was within the range of mean ± 2 SD of the historical control data. In addition, no significant changes were observed in other hematological parameters related to blood coagulation such as activated partial thromboplastin time and platelet count. Moreover, significant decreases in mean corpuscular volume and mean corpuscular hemoglobin in females were not considered to be of toxicological significance as no significant changes in hematocrit, hemoglobin concentration or erythrocyte count were noted.
The increase in basophil count in females of the 20000 ppm group was considered to be not of toxicological significance.
Males (table 1)
Eosinophil count in males in the 20000 ppm group was significantly decreased.
In the 500 ppm group, males showed significant decreases in mean corpuscular hemoglobin concentration and eosinophil count.
In the 20 ppm group, the nucleated cell count in the bone marrow was significantly decreased in males.
There were no significant changes in males of the 2500 ppm group.
The decrease of eosinophil count in males of the 20000 and 500 ppm group was considered to be not of toxicological significance. The decreases in mean corpuscular hemoglobin concentration of the 500 ppm group and nucleated cell count in bone marrow of the 20 ppm group were not treatment-related as there was no dose response relationship.

CLINICAL CHEMISTRY
Females (table 2)
In the 20000 ppm group, females showed significant increases in gamma-glutamyl transpeptidase and total cholesterol. Females showed also a significant increase in albumin, but no significant change in total protein was observed.
In the 2500 ppm group, females showed a significant increase in total cholesterol. Females showed also a significant increase in triglyceride and a significant decrease in chloride.
There were no significant changes in females treated at 500 and 20 ppm.
Significant increase in total cholesterol at 20000 and 2500 ppm and in gamma-glutamyl transpeptidase at 20000 ppm were considered to be treatment-related and due to effects on the liver.
In general, changes detected in serum protein fraction (albumin levels) were considered to be of no biological significance.
The increase in triglyceride and the decrease in chloride in the 2500 ppm group were considered to be incidental as there was no dose response relationship.
Males (table 2)
In the 20000 ppm group, males showed significant increases in gamma-glutamyl transpeptidase and total cholesterol. Also significant increases in albumin/globulin ratio and potassium, and a significant decrease in alkaline phosphatase were noted.
In the 2500 ppm group, males showed a significant increase in total cholesterol. Potassium values were also significantly increased.
There were no significant changes in males treated at 500 and 20 ppm.
Significant increase in total cholesterol at 20000 and 2500 ppm and in gamma-glutamyl transpeptidase at 20000 ppm were considered to be treatment-related and due to effects on the liver.
An increase in potassium levels in the 20000 and the 2500 ppm dose groups was considered not to be of biological significance as the values were lower than the historical control data.
In general, changes detected in serum protein fraction (albumin levels) were considered to be of no biological significance.
A decrease in alkaline phosphatase levels was noted in males of the 20000 ppm group but with no toxicological significance.

URINALYSIS
Females
The 20000 ppm group showed a significant decrease in specific gravity. There were no significant changes in urinalysis in females treated at 2500, 500 and 20 ppm.
As an increase in relative kidney weight was observed in the high dose females, the decrease in specific gravity was considered to be treatment-related. However, the toxicological significance of the finding in kidney weight and specific gravity was considered to be limited.
Males
Only the 2500 ppm group showed a significant increase for bilirubin. There were no significant changes in urinalysis in males treated at 20000, 500 and 20 ppm. The increased bilirubin levels are considered to be incidental as there is no dose response relationship.

NEUROBEHAVIOUR
Females
In the 20000 ppm group, females showed significant decreases in motor activity from 10 to 20 min.
In the 2500 ppm group, females showed significant decreases in motor activity from 10 to 20 min and 40 to 50 min.
In the 500 ppm group, females showed significant decreases in motor activity from 40 to 50 min and 50 to 60 min as well as total motor activity throughout 60 min.
In the 20 ppm group, females showed significant decreases in motor activity from 40 to 50 min.
Historical control data of motor activity in rats of the same strain and at the same age showed lower values compared to the control group of the study. Motor activity in the treated groups was rather higher than the historical control values at all intervals even when motor activity in the treated groups was lower than the concurrent control group except for 50 to 60 minutes in the 500 ppm group. Therefore, the significant decreases observed in females of the treated groups were due to the high values of the control group and not considered to be treatment-related. A marked low value of motor activity in females of the 500 ppm group (50 to 60 minutes) was considered to be incidental as there was no dose response relationship.
Males
There were no significant changes in males.

ORGAN WEIGHTS
Females (table 3)
In the 20000 ppm group, significant increases were observed in absolute and relative liver weights and in relative kidney weights.
In the 2500 ppm group, significant increases were noted in relative and absolute liver weights.
Males (table 3)
In the 20000 ppm group, significant increases were noted in absolute and relative liver weights.
In the 2500 ppm group, significant increases were noted in relative liver weights.
In the 20 ppm group, males showed significant increases in absolute and relative thymus weights.
There were no significant changes in males and females treated at 500 ppm.
The increases in absolute and relative thymus weights in males of the 20 ppm group are considered to be incidental as there is no dose response relationship.

GROSS PATHOLOGY
There were no marked changes in the incidence and type of lesions in males and females in any treatment groups.

HISTOPATHOLOGY: NON-NEOPLASTIC
Significant treatment-related changes in the incidence of lesions were observed in males and females in the 20000 ppm group (table 4). In males and females, the incidence of mucosal epithelial hyperplasia of the limiting ridge of the forestomach was significantly increased. The lesion was localised in the border area between the fore- and glandular stomach, and the degree of intensity was slight in all of the cases. It was not accompanied by inflammatory changes such as ulcer.
Other microscopic lesions listed below were observed in animals of the 20000 ppm group and were not noted in animals of the control groups; they are, however, spontaneous lesions commonly observed in rats of the same strain and at the same age: increased extramedulary hematopoiesis of the spleen, acinar cell atrophy of the pancreas, pelvic dilatation in the kidney, and fat necrosis in the abdominal cavity in males; hepatodiaphragmatic nodule in the liver, and hydropic degeneration of follicular epithelial cell of the thyroid in females.

Effect levels

Dose descriptor:

NOAEL

Effect level:

500 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

Table 1: Hematology

Parameter	Sex and dose [ppm]
	Male				Female
	20	500	2500	20000	20	500	2500	20000
Mean corpuscular volume (MCV) [%]#	101	100	100	100	100	100	99	96*
Mean corpuscular hemoglobin (MCH) [%]#	101	98	99	99	100	100	98	95*
Mean corpuscular hemoglobin concentration (MCHC) [%]#	100	98**	99	100	100	100	100	99
Prothrombin time (PT)   [%]#	95	99	94	90	98	99	96	95**
Total leukocyte count (WBC)   [%]#	96	97	106	103	117	128	127	140*
Differential leukocyte count
Lymphocyte (L)   [%]#	97	102	114	107	127	143**	142**	164*
Eosinophil (E)   [%]#	100	60*	90	60*	117	133	100	83
Basophil (B)   [%]#	100	100	100	100	100	100	100	100**
Nucleated cell count in bone marrow   [%]#	86**	100	89	93	103	102	108	100

#Figures show ratios (%) to the control values (100%); *p≤0.01; **p≤0.05 (by Dunnett´s multiple comparison test).

 

Table 2: Biochemistry

Parameter	Sex and dose [ppm]
	Male				Female
	20	500	2500	20000	20	500	2500	20000
Alkaline phosphatase (ALP)   [%]#	108	89	90	77**	97	78	85	91
Gamma-Glutamyl transpeptidase (GGTP)   [%]#	0	100	100	200*	(0)	(1)	(1)	(1)*
Albumin (Alb)   [%]#	100	99	101	103	101	100	104	107**
Albumin/globulin ratio (A/G ratio)   [%]#	105	104	108	108**	102	102	103	108
Total cholesterol (T. Chol.)   [%]#	119	117	128*	156*	110	110	129**	156*
Triglyceride (TG)   [%]#	85	82	98	113	130	105	175**	135
Potassium (K)   [%]#	102	104	108**	107**	100	101	103	99
Chloride (Cl)   [%]#	100	100	100	99	100	100	98**	98

#Figures show ratios (%) to the control values (100%). For GGTP in females: actual measurement values (U//L) were given in parentheses because the control value was zero; *p≤0.01; **p≤0.05 (by Dunnett´s multiple comparison test).

 

Table 3: Organ weights

Organs		Sex and Dose [ppm]
		Males				Females
		20	500	2500	20000	20	500	2500	20000
Final body weight		100	99	99	95	98	97	103	99
Thymus	Absolute wt.  [%]#	131**	112	104	101	100	103	95	96
	Relative wt.   [%]#	132**	112	104	106	99	106	93	97
Liver	Absolute wt.   [%]#	102	100	109	123*	99	102	115*	123*
	Relative wt.   [%]#	103	101	111*	129*	102	104	113*	126*
Kidneys	Relative wt.   [%]#	97	98	102	105	103	105	105	109*

#Figures show ratios (%) to the control values (100%); *p≤0.01; **p≤0.05 (by Dunnett´s multiple comparison test)

 

Table 4: Histopathology

Organs/lesion	Sex and Dose [ppm]
	Males					Females
	0	20	500	2500	20000	0	20	500	2500	20000
Number of animals examined	10	10	10	10	10	10	10	10	10	10
Forestomach, Hyperplasia, mucosal epithelium in limiting ridge	0	0	0	0	7*	0	0	0	0	5*

*p≤0.01; **p≤0.05 (by Fisher´s exact probability test)