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Diss Factsheets

Administrative data

Endpoint:
cytotoxicity
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: - meets generally accepted scientific principles - reported information too limited for thorough assessment

Data source

Reference
Reference Type:
publication
Title:
N-methyl-N-nitro-N'-nitrosoguanidine, guanidine carbonate and guanidine nitrate--different action of single oral doses on cell proliferation in male rats.
Author:
Urban H, Danz M
Year:
1983
Bibliographic source:
Exp Pathol. 1983;24(2-3):189-96. PMID:6685659

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Guanidine carbonate (GC), Guanidine nitrate (GN) and N-methyl-N-nitro-N'-nitrosoguanidine (MNNG) were applied once at 60 mg/kg bw (dissolved in 1 % (w/w) cellulose ether in water) to random bred Sprague Dawley rats. After sacrifice 48 h post dosing different tissues were analysed.
GLP compliance:
no
Type of method:
in vivo
Endpoint addressed:
other: mitotic activity

Test material

Constituent 1
Chemical structure
Reference substance name:
Diguanidinium carbonate
EC Number:
209-813-7
EC Name:
Diguanidinium carbonate
Cas Number:
593-85-1
Molecular formula:
CH5N3.1/2CH2O3 (one guanidine species, as denoted in the ESIS database) CH5N3.CH5N3.CH2O3 (as in the crystalline from, basis for the molecular weight 180.1658 g/mol as given below)
IUPAC Name:
bis[amino(imino)methanaminium] carbonate
Details on test material:
- Name of test material (as cited in study report): Guanidine carbonate (GC), Guanidine nitrate (GN) and N-methyl-N-nitro-N'-nitrosoguanidine (MNNG)
- Provider: MNNG: Serva Heidelberg, FRG, ; GC and GN: VEB Berlin-Chemie, GDR

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: random bred male Sprague Dawley rats
- Age at study initiation: 70 d
- Weight at study initiation: not reported
- Fasting period before study: not reported
- Housing: in plastic boxes
- Diet (e.g. ad libitum): ad libitum, standard pellets: VEB KIM Altglienicke, Berlin, GDR
- Water (e.g. ad libitum): ad libitum, tap water
- Acclimation period: not reported

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 ± 2
- Humidity (%): not reported
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
other: 1 % (w/w) cellulose ether (tylose) in water
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
- substance dissolved in the vehicle.

Analytical verification of doses or concentrations:
no
Details on analytical verification of doses or concentrations:
n/a
Duration of treatment / exposure:
single oral exposure
Frequency of treatment:
single oral exposure
Post exposure period:
48 h
Doses / concentrations
Remarks:
Doses / Concentrations:
60 mg/kg bw
Basis:
actual ingested
No. of animals per sex per dose:
7 per sex and substance (only one dose group per substance + vehicle group)
Control animals:
yes, concurrent vehicle

Examinations

Examinations:
Histopathological analysis:
- sacrifice of animals via decapitation
- excision of identical sites of the upper oesophagus at the lower pole of the thyroid gland, the upper jejunum, the forestomach, the right anterior lobe of the liver and the adrenals
- fixation of tissue samples in Bouin's solution for 24 h and embedding in paraffin
- mitotic counting of pro-, meta-, ana- and telophases performed in HE stained sections of 5-7pm thickness.
- referring of the number of adrenocortical mitoses to equatorial sections: the MI refers to 2,000 nuclei (liver), to 2,500 nuclei (jejunum) or 500 nuclei (forestomach)
- only longitudinally cut crypts evaluated in the jejunum
- statistical evaluation of the average mitotic number of three cross sections per animal in the oesophagus
- calculation of the two-sided levels of error (p-values) by means of the parameter free u-test by MANN and WHITNEY.

Results and discussion

Details on results:
Inhibition of cell proliferation
- MNNG has generally strong inhibitory effects on cell proliferation.
- GC and GN do not affect significantly the mitotic activity of any investigated tissues except for the reduction of the proliferation of the forestomach epithelium by GN
- see table 1 for details

Any other information on results incl. tables

Table 3: Different effects of MNNG, Guanidine carbonate and Guanidine nitrate on the mitotic activity. n represents the number of animals

 

Mitoses per section (mean ± S.D.)

Mitotic index (mean ± S.D.)

 Test substance

n

adrenal cortex

n

oesophagus

n

liver (‰)

n

jejunum (%)

n

forestomach (%)

Solvent control (tylose)

7

13.2±3.82

7

31.4±4.03

7

1.7±0.85

6

4.7±0.52

6

3.6±0.51

Guanidine carbonate

7

12.3±3.45

7

32.9±1.20

7

1.0±0.86

7

4.4±0.45

-

not investigated

Guanidine nitrate

6

14.7±2.16

6

30.6±4.71

6

1.7±0.63

6

4.4 ± 0.45

5

2.2±0.97*)

MNNG

7

19.3±5.40*)

6

20.0±3.50*)

7

9.3±6.96*)

7

3.9±0.38*)

7

1.3±0.81*)

*) p ≤ 0.05

Applicant's summary and conclusion

Conclusions:
In a specific investigation Guanidine carbonate (GC), Guanidine nitrate (GN) and N-methyl-N-nitro-N'-nitrosoguanidine (MNNG) were applied once at 60 mg/kg bw (dissolved in 1 % (w/w) cellulose ether in water) to random bred Sprague Dawley rats (group size 6 - 7). After sacrifice 48 h post dosing different tissues were analysed for a decrease in the mitotic index as compared to the solvent control group. MNNG was found to have generally strong inhibitory effects on cell proliferation in all analysed tissues. GC and GN do not affect significantly the mitotic activity of any investigated tissues except for the reduction of the proliferation of the forestomach epithelium by GN.
Executive summary:

In a specific investigation Guanidine carbonate (GC), Guanidine nitrate (GN) and N-methyl-N-nitro-N'-nitrosoguanidine (MNNG) were applied once at 60 mg/kg bw (dissolved in 1 % (w/w) cellulose ether in water) to random bred Sprague Dawley rats (group size 6 - 7). After sacrifice 48 h post dosing different tissues were analysed for a decrease in the mitotic index as compared to the solvent control group. MNNG was found to have generally strong inhibitory effects on cell proliferation in all analysed tissues. GC and GN do not affect significantly the mitotic activity of any investigated tissues except for the reduction of the proliferation of the forestomach epithelium by GN.

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