Registration Dossier

Administrative data

Endpoint:
toxicity to reproduction: other studies
Type of information:
experimental study
Adequacy of study:
disregarded due to major methodological deficiencies
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Not to GLP, No a standard study but follows basic scientific principles

Data source

Reference
Reference Type:
publication
Title:
Effect of zinc on manganese induced testicular injury in rats
Author:
Chandra SV , Saxena DK and Hasan MZ
Year:
1975
Bibliographic source:
Ind. Health, 13: 51-56

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
4 groups of 10 rats were used, group 1 was exposed to the control, group 2 was exposed to MnSO4, group 3 was exposed to ZnSO4 and group 4 was exposed to both MnSO4 and ZnSO4 daily via i.p injection for 30 days. All animals were sacrificed at the end of the exposure period; 1 testis was kept for the estimation of the manganese of zinc content and the other testis was fixed for histology.
GLP compliance:
no
Type of method:
in vivo

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Manganese sulphate (B.D.H.)
- Molecular formula (if other than submission substance): MnSO4.4H2O
- Analytical purity: Analytical reagent quality

Test animals

Species:
rat
Strain:
other: Hooded
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Industrial Toxicology Research Centre bred
- Age at study initiation: Not reported
- Weight at study initiation: 150 ± 20 g
- Diet : Pellet diet from Hindustan Levers India Ltd. ad libitum
- Water : Tap water ad libitum

Administration / exposure

Route of administration:
intraperitoneal
Vehicle:
physiological saline
Details on exposure:
PREPARATION OF DOSING SOLUTIONS: 6 mg/kg of MnSO4.4H2O dissolved in 0.2 mL of physiological saline. 2 mg/kg of ZnSO4.7H2O dissolved in 0.2 mL physiological saline.

- Dosing scheme: Group 1 was exposed to the control, group 2 was exposed to MnSO4, group 3 was exposed to ZnSO4 and group 4 was exposed to both MnSO4 and ZnSO4 daily via i.p injection for 30 days.
Analytical verification of doses or concentrations:
no
Details on analytical verification of doses or concentrations:
Not applicable
Duration of treatment / exposure:
30 days
Frequency of treatment:
Single daily treatment for 30 days for groups I, II and III. For group IV, animals were dosed once in the morning with ZnSO4 (same concentration and volume) and dosed once in the afternoon of the same day with MnSO4 (same concentration and volume) for 30 days.
Duration of test:
Not applicable
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
6 mg/kg
Basis:
nominal conc.
MnSO4 in 0.2 mL physiol. saline
Remarks:
Doses / Concentrations:
2 mg/kg
Basis:
nominal conc.
ZnSO4 in 0.2 mL physiol. saline
No. of animals per sex per dose:
10 animals were dosed in each group
Control animals:
yes, concurrent vehicle
Details on study design:
At the end of the experimental period, all animals were sacrificed under ether anaesthesia. One testis was kept for the estimation of manganese and zinc contents and the other testis from each rat was fixed in 10% neutral formalin for histology. After routine processing the tissues were embedded in paraffin and sections were cut at 5 µ. The staining was done with haematoxylin and eosin and for the histochemical demonstration of calcium by the method of Von Kossa.
Statistics:
Data were analysed by Fisher's test. The statistical significance was calculated between two values of control and treated rats and a p value of 0.05 or less was considered significant.

Results and discussion

Effect levels

Dose descriptor:
conc. level:
Effect level:
6 mg/kg bw/day (nominal)
Sex:
male
Basis for effect level:
other: A decrease in the number of spermatocytes was noted along with degeneration in the seminiferous epithelium

Observed effects

HISTOPATHOLOGY: The sections of the testis after administration of manganese sulphate (6mg Mn/kg) showed degenerative changes in the seminiferous epithelium of some of the tubules, the number of spermatids were markedly depleted and these tubules were devoid of spermatocytes. Rats treated with zinc sulphate did not show any morphological change. Rats treated with both salts did not reveal any pathological change.

Any other information on results incl. tables

Table 1: Manganese and zinc contents in testis

 

Groups (No. of Rats)

Treatment given daily for 30 days

Manganese contents µg/g of wet tissue

Zinc contents µg/g of wet tissue

I (10)

0.2 mL physiological saline intraperitoneally (controls)

0.302 ± 0.06

6.753 ± 0.72

II (10)

MnSO4.4H2O, 6 mg Mn/kg intraperitoneally

0.723 ± 0.01

p < 0.01

8.111 ± 0.6

p < 0.05

III (10)

ZnSO4.7H2O, 2 mg Zn/kg intraperitoneally

0.429 ± 0.01

N.S.

9.80 ± 0.5

p < 0.01

IV (10)

MnSO4.4H2O, 6 mg Mn/kg and ZnSO4.7H2O, 2 mg Zn/kg intraperitoneally

0.573 ± 0.01

p < 0.01

11.09 ± 0.32

p < 0.001

Values represent the mean ± S.E. of 6 rats p values of 0.05 or less are significant

 

Applicant's summary and conclusion

Conclusions:
The increase in manganese content in testis of rats treated with both manganese and zinc sulphates is less than in testicular tissue of animals administered with manganese sulphate alone. It was also observed that the increase in the testicular contents of zinc is more in animals treated with both the salts as compared to the zinc contents of testis after treatment with zinc sulphate alone. The simultaneous administration of zinc and manganese in experimental animals results in less accumulation of manganese and more concentration of zinc in testis. Excess of zinc may be preventing the interference of manganese with the energy synthesizing enzyme system of the cells of seminiferous tubules and therefore preventing cellular death.