kresoxim-methyl (ISO);methyl (E)-2-methoxyimino-[2-(o-tolyloxymethyl)phenyl]acetate

Repeated dose toxicity: oral

Administrative data

Endpoint:

chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (no ophthalmoscopic examination, urinalysis or neurobehavioural examination)

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 452 (Chronic Toxicity Studies)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPP 83-1 (Chronic Toxicity)

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Japan/MAFF: Testing Guidelines for Toxicology Studies; Chronic Toxicity Study; p. 37 - 49, 1985

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

methyl (2E)-2-methoxyimino-2-[2-[(2-methylphenoxy)methyl]phenyl]acetate

EC Number:

604-351-6

Cas Number:

143390-89-0

Molecular formula:

C18 H19 N O4

IUPAC Name:

methyl (2E)-2-methoxyimino-2-[2-[(2-methylphenoxy)methyl]phenyl]acetate

Details on test material:

- Name of test material (as cited in study report): Reg. No. 242 009 (test substance number: 91/180 (used from May 23, 1991 to September 19, 1991), 91/180-1 (used from September 18, 1991 to April 29, 1992) and 91/180-2 (used from from April 23, 1992 to June 30, 1993); lab code letters: STUR)
- Lot/batch No.: N 27 (III a1), N 30 (III a2) and N 36 (III c1) respectively; date of manufacturing: April 05, 1991, June 17, 1991 and October 23, 1991 respectively
- Storage condition of test material: dark, +4°C
- Physical state: solid (powder) / light brown
- Analytical purity: 94% and 95.9% respectively (Reversed-Phase - HPLC with UV-Detection)
- Stability under test conditions: the storage stability was guaranteed over the study period
- Other: the homogeneity of the test substance was confirmed by analysis (Reversed-Phase - HPLC with UV-Detection)

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Wistar rats (CHBB: Thom; SPF); from Dr. K. Thomae GmbH, D-W7950 Biberach/Riss, FRG
- Age at study initiation: the male animals were supplied on May 13, 1991 and the female animals on May 27, 1991 at an age of 32 days (males) or 33 days (females), respectively; 42 days old when the administration of the test substance started
- Weight at study initiation: animals of comparable weight; 196 g (181 - 213 g) for males and 147 g (134 - 165 g) for females at treatment begin.
- Fasting period before study: none specified
- Housing: singly in stainless steel wire mesh cages, Type DK-III (Becker & Co., Castrop-Rauxel, FRG; floor area about 800 cm2)
- Diet (e.g. ad libitum): Kliba maintenance diet rat/mouse/hamster, 343 meal, supplied by Klingentalmuhle AG; CH-4303 Kaiseraugst, Switzerland
- Water (e.g. ad libitum): drinking water
- Acclimation period: on the day of arrival a 10-day (males) or 9-day (females) adaption period started

ENVIRONMENTAL CONDITIONS
The animals were housed in fully air-conditioned rooms. There were no deviations from these ranges which influenced the results of the study.
- Temperature (°C): 20 - 24
- Humidity (%): 30 - 70
- Photoperiod (hrs dark / hrs light): 12/12 (6:00 - 18:00 / 18:00 - 6:00 hours)

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:

DIET PREPARATION
- Rate of preparation of diet (frequency): weekly
- Mixing appropriate amounts with (Type of food): substance weighed was thoroughly mixed with a small portion of the feed and subsequently mixed using a BOSCH mixer. This premix was then adjusted to the concentration desired with the appropriate amount of feed and mixed in a laboratory mixer of GEBR. LOEDIGE for about 10 minutes.
- Storage temperature of food: room temperature

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Before the start of the study the stability of the test substance in the diet over 10 and 32 days was ordered (HPLC with UV-Detection). The homogeneity analysis of the mixtures was ordered on the lowest and highest dose also as the concentration control at the beginning of the study.

Duration of treatment / exposure:

24 months

Frequency of treatment:

continuously

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
0, 200, 800, 8000 and 16000 ppm
Basis:
nominal in diet

Doses / concentrations 2

Remarks:

Doses / Concentrations:
about 9 (males) /12 (females), 36 / 48, 370 / 503 mg/kg and 746 / 985 mg/kg bw
Basis:
other: Based on diet consumption; the content of test substance in the test substance/food mixes was determined by HPLC with UV detection.

No. of animals per sex per dose:

20

Control animals:

yes, plain diet

Details on study design:

- Dose selection rationale: the selection of the doses for this study was based on results of previous studies:
(1) In a 4-week study the test substance was administered to 5 male and 5 female Wistar rats per group at doses of 1000, 4000 and 16000 ppm in the diet. Following substance-induced findings were observed: (a) 16000 ppm (about 1455 mg/kg body weight); increased values of γ-glutamyltransferase and albumin in male animals. (b) 4000 ppm (about 370 mg/kg body weight) and 1000 ppm (about 93 mg/kg body weight); no substance-induced changes

(2) In a 3-month study the test substance was administered to 10 male and 10 female Wistar rats per group at doses of 500, 2000, 8000 and 16000 ppm in the diet. Following, substance-related adverse findings were observed: (a) 16000 ppm (about 1272 mg/kg body weight); slightly reduced body weights in males (resulting in reduced values of about 6% at the end of the study), reduced body weight change in males (resulting in reduced values of about 9% at the end of the study), decrease in aspartate aminotransferase in the males, increase in γ-glutamyltransferase in the serum of the males, statistically significant increase of the relative liver weight confirmed in both sexes and distinct change of the distribution and the amount concerning the fatty infiltration in the liver of both sexes. (b) 8000 ppm (about 625 mg/kg body weight); slightly reduced body weights in males (resulting in reduced values of about 9% at the end of the study), reduced body weight change in males (resulting in reduced values of about 14% at the end of the study), decrease in aspartate aminotransferase in the males, increase in γ-glutamyltransferase in the serum of the males, statistically significant increase of the relative liver weight in the females, and distinct decrease of the amount and a change of the distribution pattern of the fat in the liver of the females. (c) 2000 ppm (about 159 mg/kg body weight); statistically significant increase of the relative liver weight in female animals, without a morphological correlate. (d) 500 ppm (about 40 mg/kg body weight); no substance-related adverse effects.

Based upon these results, following dose levels were chosen for the present study: (a) 16000 ppm as highest dose level which should cause toxic effects. Moreover, this dose level should result in a test substance intake close to 1000 mg/kg body weight per day, which is the highest dose recommended for testing according to EPA's present MTD concept. (b) 8000 and 800 ppm as intermediate doses. (c) 200 ppm: as lowest dose level which should result in a clear "no observed adverse effect level".

Positive control:

None

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: a check was made twice (Mondays to Fridays) and once a day (Saturdays, Sundays and on public holidays) for general observations and for any dead or moribund animals. Once a week an additional exact clinical examination was carried out.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: see above; a check was made twice a day Mondays to Fridays and once a day Saturdays, Sundays and on public holidays for any dead or moribund animals.

BODY WEIGHT: Yes
- Time schedule for examinations: all animals; in order to randomize the animals body weight was determined before the start of the administration period and once a week during the first 13 weeks of the study, and at 4-week intervals thereafter up to the end of the study. The difference between the body weight on the respective day of weighing and the body weight on day 0 was calculated as the body weight change.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- 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: Yes

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: Yes

OPHTHALMOSCOPIC EXAMINATION: Yes
Prior to the start of the study and at the end of the administration period the eyes of all animals of the control group and highest dose group were examined using an ophthalmoscope (HEINE FOCALUX).

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at days 92, 179/180, 365, 547/548 and 729/732 blood was taken from the retroorbital venous plexus in the morning from non-fasted animals. For hormone examinations blood was collected after decapitation
- Anaesthetic used for blood collection: No
- Animals fasted: No
- How many animals: all
- Parameters examined: parameters determined using a particle counter (leukocytes, erythrocytes, hemoglobin, haematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration and platelets); clotting analyses (carried out using a ball coagulometer; thromboplastin time).

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: see above
- Animals fasted: Yes; only for hormone examination (see above)
- How many animals: all
- Parameters examined: enzymes (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and γ-glutamyltransferase); blood chemistry (sodium, potassium, chloride, inorganic phosphate, calcium, urea, creatinine, glucose, total bilirubin, total protein, albumin, globulins, triglycerides, cholesterol and magnesium).

URINALYSIS: Yes
- Time schedule for collection of urine: days 99, 187, 376, 554 and 726
- Metabolism cages used for collection of urine: Yes
- Animals fasted: No
- Parameters examined: volume, color, turbidity, nitrite, pH, protein, glucose, ketones, urobilinogen, bilirubin, blood, specific gravity, sediment

NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes; At the end of the study and after 16 - 20 hours fasting period, the animals were sacrificed by decapitation under C02 anesthesia. The exsanguinated animals were necropsied and assessed by gross pathology. The animals which died intercurrently were necropsied and assessed by gross pathology as soon as possible after death. From all animals sacrificed at the end of the study, the terminal body weight as well as the weights of adrenal glands, brain, kidneys, liver, and testes were determined.

HISTOPATHOLOGY: Yes; subsequently to the gross-pathological examinations, the following organs or tissues were fixed in 4% formaldehyde solution: Adrenal glands, aorta, bone (sternum, femur), bone marrow (sternum), brain, cecum, colon, duodenum, epididymides, esophagus, eyes, female mammary gland area, femorotibial joint, heart, ileum, jejunum, kidneys, liver, lungs, lymph nodes (mandibular, mesenteric), ovaries, oviducts, pancreas, parathyroid glands, pituitary gland, prostate gland, rectum, salivary glands (mandibular, sublingual), sciatic nerve, seminal vesicles, skeletal muscle, skin, spinal cord (cervical, thoracic, lumbar), spleen, stomach, testes, thymus, thyroid gland, trachea, urinary bladder, uterus, vagina, and all macroscopic abnormalities. After the organs have been fixed, processing, the examination by light microscopy and the evaluation of findings was performed.

Other examinations:

None

Statistics:

(1) Clinical examinations: mean and standard deviation were calculated for the variables feed consumption, body weight and test substance intake for each group and tabulated together with the individual values for feed consumption and body weight. The statistical significance of the clinical data (body weight) was checked using the KRUSKAL-WALLIS test and the MANN-WHITNEY U-test. (2) Clinical chemistry and hematology: mean and standard deviation were calculated for each test group and tabulated together with the individual values. Except for the differential blood count, a statistic one-way analysis of variance is done via the KRUSKAL-WALLIS test. If the resulting p-value is equal or less than 0.05 a pairwise comparison of each dose group with the control group was carried out. This comparison is done using the MANN-WHITNEY U-test for the hypotheses of equal medians. (3) Urinalyses: A pairwise comparison of each dose group with the control was carried out using FISHER's exact test for the hypothesis of equal proportions. (4) Pathology: mean and standard deviation were calculated for the statistical evaluation of the study for the variables of body weight and of absolute and relative organ weights (related to body weight) of the animals in each test group and tabulated together with the individual values (absolute and relative organ weights). A non-parametric one-way analysis of variance was done via the KRUSKAL-WALLIS-h test. If the resulting p-value is less than 0.05 a pairwise comparison of each dose group with the control group was carried out. This comparison was performed using the WILCOXON-Test for the hypothesis of equal medians.

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

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

not specified

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

effects observed, treatment-related

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not specified

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

effects observed, treatment-related

Details on results:

CLINICAL SIGNS AND MORTALITY
- No substance-related effects were obtained in any of the doses tested. The clinical findings throughout the study in all groups occurred sporadically both in controls and treated animals and were not treatment-related.

- In males the mortality until day 735 was 15% in test group 0, 60% in test group 1, 25% in test group 2, 20% in test group 3, and 20% in test group 4. In females the mortality until day 735 was 25% in test group 0, 25% in test group 1, 40% in test group 2, 20% in test group 3, and 15% in test group 4 (see Table 1). Thus, the administration of the test substance did not influence the survival of the animals. The high mortality in males of test group 1 was assessed as being incidental.

BODY WEIGHT AND WEIGHT GAIN
In males of test groups 3 and 4, body weight was very slightly impaired throughout the study (about 5% below controls), with statistical significance on day 42 (test group 4). This was assessed to be substance-related. In males of test group 1 and 2, body weights were slightly higher than controls (without statistical significance). This was assessed as being incidental.
In females of test groups 3 and 4, body weight was impaired statistically significant on several days and the values were roughly about 10% below controls. In females of test groups 1 and 2, there were isolated statistically significant deviations on days 42 and 91. The statistically significant deviations in groups 1 and 2 were assessed as being incidental, as they occurred only sporadically, and as in males treated with the same dose levels body weights were even higher than controls.
Body weight change values were impaired statistically significant in males of test groups 3 and 4 on several days, and the values were roughly about 10% below controls. In males of test group 1 and 2, body weight changes were slightly higher than controls (without statistical significance). This was assessed as being incidental.
In females of test groups 3 and 4, body weight change was impaired statistically significant on most of the days and the values were about 15% below controls. In females of test groups 1 and 2, there were lower values with statistical significance on few days. The statistically significant deviations in groups 1 and 2 were assessed as being incidental, as they occurred only sporadically, and as in males treated with the same dose levels body weight changes were even higher than controls.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
No clear substance-related findings were obtained. All values were within the biological range of variation.
No abnormalities in test substance intake (see Table 2)

FOOD EFFICIENCY
No substance-related effects were seen. All values were within the biological range of variation.

OPHTHALMOSCOPIC EXAMINATION
The ophthalmological examinations carried out revealed no substance-related findings.

HAEMATOLOGY
No substance-induced changes were observed in the hematological parameters and clotting analyses. No substance-related changes were observed in the results of the clotting analyses of both sexes.

CLINICAL CHEMISTRY
- Enzymes (see Table 3-5): the test substance caused conspicuous changes in the serum enzyme activities examined. Among the parameters tested alanine aminotransferase (decrease), alkaline phosphatase (decrease) and γ-glutamyltransferase (increase) showed statistically significant differences compared to the corresponding control. The decrease in alkaline phosphatase activity (range: 10-40%; Table 3) and in alanine aminotransferase activity (range 15-30%; Table 4), although mostly significant in treatment groups, showed no clear dose-response relationship. In contrary, the increase in γ-glutamyltransferase activity (only in males; Table 5) was dose-related and rose continuously in the course of the study.

- Blood chemistry: No substance-related changes were observed in the blood chemistry parameters of the treatment animals in either sex.

- Other deviations were observed, but are marginal, incidental or inconsistent, when compared with the other sex. Accordingly, these changes are considered to be of no toxicological significance.

URINALYSIS
No substance-related changes were observed in the results of the urinalyses of both sexes.

ORGAN WEIGHTS
At postmortem examination of the animals, a toxicologically significant increase in relative liver weight was recorded for males of groups 3 (8000 ppm) and 4 (16000 ppm); the absolute weight was increased in males of group 4.

GROSS PATHOLOGY
As compared with controls, the incidence of liver masses was increased in both sexes combined of groups 3 and 4. The incidence of cysts in the liver was also increased in males and in both sexes combined of group 4. The remainder of macroscopic findings was considered to be spontaneous in 'nature.

HISTOPATHOLOGY: NEOPLASTIC AND NON-NEOPLASTIC
At gross and microscopic examination, a significant increase in liver tumors was recorded in groups 3 and 4. Histopathologically, a total of 9 and 14 carcinomas were present in these groups as compared to one in control females. In males, the incidence in groups 3 and 4 was 3 and a, in females 6 and 6. These differences proved to be statistically significant for males of group 4 and for both sexes combined of groups 3 and 4.
Treatment-related non-neoplastic findings were also seen in the liver. The incidence and degree of severity of slight to severe eosinophilic foci of hepatocellular alteration increased in males of groups 3 and 4. Minimal to moderate hepatocellular hypertrophy increased in incidence and severity in males and females of group 4.
All other neoplastic and non-neoplastic lesions recorded in this study were considered to be of a spontaneous nature.

Effect levels

Dose descriptor:

NOAEL

Effect level:

800 ppm

Sex:

male/female

Basis for effect level:

other: The "no observed adverse effect level" under the conditions of this study both for oncogenicity and for overall toxicity was 800 ppm (about 36 mg/kg body weight in males and 48 mg/kg body weight in females).

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

The following adverse findings were obtained:

(1) 16000 ppm (about 746 mg/kg body weight in males and 985 mg/kg body weight in females):

- (a) Slightly reduced values of body weight in males (about 5% below controls) and females (about 10% below controls);

- (b) Reduced values of body weight change in males (about 10% below controls) and females (about 15% below controls);

- (c) Increase in γ-glutamyltransferase in the males;

- (d) Increased absolute and relative liver weights in males;

- (e) Increased incidence of hepatocellular carcinomas in males and combined in males and females;

- (f) Increase in incidence and degree of severity of eosinophilic foci of hepatocellular alteration in males;

- (g) Increased incidence of hepatocellular hypertrophy in males and females

 

(2) 8000 ppm (about 370 mg/kg body weight in males and 503 mg/kg body weight in females):

- (a) Slightly reduced values of body weight in males (about 5% below controls) and females (about 10% below controls)

- (b) Reduced values of body weight change in males (about 10% below controls) and females (about 15% below controls)

- (c) Increase in γ-glutamyltransferase in the males

- (d) Increased relative liver weight in males

- (e) Increased incidence of hepatocellular carcinomas (males and females combined)

- (f) Increase in incidence and degree of severity of eosinophilic foci of hepatocellular alteration in males

 

(3) 800 ppm (about 36 mg/kg body weight in males and 48 mg/kg body weight in females):

- (a) No substance-related adverse effects

 

(4) 200 ppm (about 9 mg/kg body weight (males) and 12 mg/kg body weight (females):

- (a) No substance-related adverse effects

 

Table 1: Mortality

Days after treatment begin	Number of deaths (%) in the indicated treatment group after the indicated days after treatment begin
	Group 0 (0 ppm)		Group 1 (200 ppm)		Group 2 (800 ppm)		Group 3 (8000 ppm)		Group 4 (16000 ppm)
	Males	Females	Males	Females	Males	Females	Males	Females	Males	Females
0	0 (0%)	0 (0%)	0 (0%)	0 (0%)	0 (0%)	0 (0%)	0 (0%)	0 (0%)	0 (0%)	0 (0%)
147	0 (0%)	0 (0%)	0 (0%)	0 (0%)	1 (5%)	0 (0%)	0 (0%)	0 (0%)	0 (0%)	0 (0%)
343	0 (0%)	0 (0%)	0 (0%)	0 (0%)	1 (5%)	0 (0%)	0 (0%)	0 (0%)	1 (5%)	0 (0%)
399	0 (0%)	0 (0%)	0 (0%)	0 (0%)	1 (5%)	1 (5%)	0 (0%)	0 (0%)	1 (5%)	0 (0%)
427	0 (0%)	0 (0%)	1 (5%)	0 (0%)	1 (5%)	1 (5%)	0 (0%)	0 (0%)	1 (5%)	0 (0%)
483	0 (0%)	0 (0%)	1 (5%)	1 (5%)	1 (5%)	1 (5%)	0 (0%)	0 (0%)	1 (5%)	0 (0%)
511	0 (0%)	0 (0%)	1 (5%)	1 (5%)	1 (5%)	1 (5%)	0 (0%)	0 (0%)	1 (5%)	1 (5%)
539	0 (0%)	1 (5%)	1 (5%)	1 (5%)	1 (5%)	1 (5%)	0 (0%)	1 (5%)	2 (10%)	2 (10%)
567	0 (0%)	1 (5%)	1 (5%)	2 (10%)	2 (10%)	1 (5%)	0 (0%)	1 (5%)	2 (10%)	2 (10%)
595	1 (5%)	1 (5%)	2 (10%)	2 (10%)	3 (15%)	3 (15%)	0 (0%)	2 (10%)	2 (10%)	2 (10%)
623	2 (10%)	1 (5%)	4 (20%)	4 (20%)	4 (20%)	4 (20%)	0 (0%)	3 (15%)	2 (10%)	3 (15%)
651	2 (10%)	2 (10%)	4 (20%)	4 (20%)	5 (25%)	7 (35%)	2 (10%)	3 (15%)	2 (10%)	3 (15%)
679	2 (10%)	2 (10%)	5 (25%)	4 (20%)	5 (25%)	7 (35%)	3 (15%)	4 (20%)	2 (10%)	3 (15%)
707	3 (15%)	3 (15%)	8 (40%)	4 (20%)	5 (25%)	7 (35%)	3 (15%)	4 (20%)	4 (20%)	3 (15%)
735	3 (15%)	5 (25%)	12 (60%)	5 (25%)	5 (25%)	8 (40%)	4 (20%)	4 (20%)	4 (20%)	3 (15%)

 

 

Table 2: Intake of test substance

Test groups	Concentration of test substance in the diet	Mean daily substance intake in mg/kg body weight
		Male	Female
1	200 ppm	About 9	About 12
2	800 ppm	About 36	About 48
3	8000 ppm	About 370	About 503
4	16000 ppm	About 746	About 985

 

Table 3: Enzyme activity; alkaline phosphatase

Treatment (enzyme activity unit)	Groups (dose level)
		Day 92		Day 179		Day 365		Day 547		Day 732
		Males	Females	Males	Females	Males	Females	Males	Females	Males	Females
Control (µkat/l)	0 (0 ppm)	4.94	3.49	4.47	3.25	4.76	2.65	4.56	2.42	4.00	2.56
Test groups (% of control)	1 (200 ppm)	88.8*	77.7*	88.5*	77.3*	83.9*	73.2*	84.3*	76.1*	88.5	74.3*
	2 (800 ppm)	77.1*	72.6*	81.5*	70.5*	77.0*	71.8*	78.3*	72.0*	81.4*	69.1*
	3 (8000 ppm)	79.1*	72.0*	83.3*	66.5*	75.8*	64.5*	74.3*	62.8*	77.0*	64.3*
	4 (16000 ppm)	76.0*	75.9*	78.0*	66.9*	71.6*	88.6*	75.8*	63.0*	77.1*	69.7*
	*: significantly different from control values; µkat/l: microkatal/liter

 

Table 4: Enzyme activity; alanine aminotransferase

Treatment (enzyme activity unit)	Groups (dose level)
		Day 92		Day 179		Day 365		Day 547		Day 732
		Males	Females	Males	Females	Males	Females	Males	Females	Males	Females
Control (µkat/l)	0 (0 ppm)	1.01	0.88	0.94	0.90	1.05	0.96	1.10	0.96	0.75	0.88
Test groups (% of control)	1 (200 ppm)	99.6	85.9	99.6	94.5	100.8	95.1	89.1	83.8	99.2	79.8
	2 (800 ppm)	86.4*	75.1*	93.7	87.6	91.7	87.0	91.3	82.5*	102.1	83.7
	3 (8000 ppm)	77.5*	76.0*	88.7*	81.5	88.7	76.6*	80.4*	76.3*	94.1	93.4
	4 (16000 ppm)	72.7*	79.3*	80.9*	83.7	87.1	84.8	70.9*	71.3*	78.0*	85.2
	*: significantly different from control values; µkat/l: microkatal/liter

 

Table 5: Enzyme activity; γ-glutamyltransferase

 

Treatment (enzyme activity unit)	Groups (dose level)
		Day 92		Day 179		Day 365		Day 547		Day 732
		Males	Females	Males	Females	Males	Females	Males	Females	Males	Females
Control (nkat/l)	0 (0 ppm)	9	2	6	16	3	3	10	0	3	0
Test groups (% of control or mean±SD when control value = 0)	1 (200 ppm)	45.5	197.9	113.3	90.6	0	175.0	16.3	0	63.0	0
	2 (800 ppm)	100.0	329.2	65.8	66.1	0	75.0	88.9	4±14	188.9	0
	3 (8000 ppm)	481.8*	625.0	618.3*	138.9	1468.9*	223.3	834.5*	2±5	2868.8*	19±50
	4 (16000 ppm)	545.5*	947.9	774.2*	191.8	2019.0*	1006.7	1305.6*	3±6	4604.2*	7±12
	*: significantly different from control values; nkat/l: nanokatal/liter