3-chloropropane-1,2-diol

Toxicity to reproduction: other studies

Administrative data

Endpoint:

toxicity to reproduction: other studies

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Clear description of material & methods and results in a non-GLP and non-guideline study.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1994

Materials and methods

Test guideline

Guideline:

other:

Principles of method if other than guideline:

Male rats (10 per group) were administered oral doses of 0, 1, 5, or 25 mg [alpha]-chlorohydrin per kg bw, once daily by gavage for 14 days.
After dosage administration on TD 14, the last day treatment, 5 males per group were cohabited with untreated virgin females (1:2) for up to 14 days. Vaginal lavage was performed daily on the cohabited female to detect the presence of sperm (evidence of mating). Females were killed by carbon dioxide asphyxiation on Gestation Day 13, 14 or 15. Numbers of corpora lutea, implantation sites, and early resorptions were counted. Fertility was expressed as percent implantation [(implantation/corpora lutea) x 100].
Five males per group were killed by carbon dioxide asphyxiation on TD 15 (termination of treatment) or 29 (2 weeks without treatment). The testes and epididymides were removed for further examination, and the testes were weighed.
Following parameters were studied: DNA flow cytometry on the right testis, histopathology of left testis and left epididymis, sperm collection from the right cauda epididymis with a short segment of the vas deferens for evaluation of sperm morphology/breakage and dertermination of the relative sperm concentrations/ motion of the samples.

GLP compliance:

not specified

Type of method:

in vivo

Test material

Test material information

Constituent 1

Reference substance name:

3-chloropropane-1,2-diol

EC Number:

202-492-4

EC Name:

3-chloropropane-1,2-diol

Cas Number:

96-24-2

Molecular formula:

C3H7ClO2

IUPAC Name:

3-chloropropane-1,2-diol

Details on test material:

- name: [alpha]-chlorohydrin; 3-chloro-1,2-propanediol, ACH
- 98% purity, purchased from Aldrich Chemical Co., Inc., Milwaukee, WI

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

- male Charles River sprague-Dawley Crl: CD(SD)BR rats
- approx. 16 weeks of age
- weight: 475 +/- 19 g (mean +/- SD)

- Adult female Crl:CD(SD)BR rats used for the purpose of mating
- approx. 9 weeks of age
- weight: 227 +/- 11 g (mean +/- SD)

- Housing: except for mating period, all rats were individually housed in ventilated cages. During cohabitation: one male + two females.
- Diet: Purina Certified Rodent Chow No 5002 and water provided at libitum
- Temp: maintained at approx. 22 +/- 2 °C
- Relative humidity: approx 50 +/- 20 %
- Photoperiod of the room: 12h light, 12h dark

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

Dose volumes were based on test day (TD) 1 and TD 8 body weights. The test volume was 5 ml/kg bw.

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

14 days

Frequency of treatment:

once daily

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 1, 5, 25 mg/kg bw/d
Basis:
actual ingested

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Details on study design:

Body weights are recorded at study initiation and at weekly intervals.
Food consumption was measured for TD 1-7 and TD 8-13.

Statistics:

General linear modeling was used.
Body weight and food consumption were analyzed using repeated measures data analysis. When a group-by-interval interaction was significant, data from each interval were analyzed for a treatment effect. Mating and fertility data were rank transformed before submitting to a one-way analysis of variance. Because each male was cohabited with 2 females, "first mating" and 'best mating" were identified to maintain the male as the sampling unit.
Values for first and best matings were analyzed separately. The remaining endpoints were analyzed using a two-way analysis of variance for day and treatment effects. Data were transformed using both a Freeman-Turkey transformation and a rank transformation. The results were consistent. Asequential trend test was applied to all endpoints for a linear trend in treatment group means. A Student-Newman-Keuls multiple range test or pair-wise t tests with Bonferroni's correction were performed for nonlinear treatment effects when the overall F-value < 0.01, and the trend test was not significant. All statements of statistical significance refer to a two-tailed P-value <= 0.05, unless otherwise stated.

Results and discussion

Effect levels

Dose descriptor:

NOAEL

Effect level:

1 mg/kg bw/day

Based on:

test mat.

Sex:

male

Basis for effect level:

other: sperm production + sperm quality/motility

Observed effects

All of the rats survived the 14-day treatment with ACH, and there were no treatment-related clinical findings. There were no treatment-related diffenrences in body weight during the 14-day period without treatment.
Main testes weights were not affected by ACH doses of 1 or 5 mg/kg/day, but were increased on TD 15 in the 25-mg/kg dose group. Of the 5 males examined on TD 15, 4 had testes weights that were 153% to 181% of the control mean. Testes weight for the remaining male was 70% of the control mean value. Although mean testes weights in the 25-mg/kg dose group were not significantly different from the control group on TD 29, 3 of 5 males had testes weights that were outside the control range and 62% to 83% of the control mean.
Changes in testicular cell DNA ploidy occurred only in males of the 25 mg/dose group. The percentage of haploid cells was depressed compared to the control values, while the percentages of diploid and tetraploid cells were increased. Alterations in the percentages of haploid and diploid cells were more pronounced on TD 29 than on TD 15.
Testicular lesions occurred in the 25-mg/kg dose group.
On TD 29, disruption of spermatogenesis was pronounced in 4 of 5 males.
Epididymal lesions also occurred only in the 25-mg/kg dose group. On TD 15, sperm were scant to absent in the tubular lumina of the initial segment.
In the caput epididymis, evidence of chronic active interstitial inflammation was observed in all 5 males, and sperm granulomas were present in 4 of 5 males. In the affected males, sperm were absent from the tubular lumina of the initial segment and caput and scant in the proximal cauda. No lesions were observed in the epididymides of males of the 1- and 5-mg/kg dose groups. The concentration of sperm in the 4-mL "swim-out" was depressed in the 25-mg/kg dose group. The mean concentrations of epididymal sperm in this dose group were 61% and 36% of the control mean for TD 15 and 29, respectively. On TD 15 sperm motion characteristics were profoundly altered in the 5-and 25-mg/kg dose groups. The percentage of motile sperm was depressed in both the 5-and 25-mg/kg dose groups. However, the percentage of motile sperm collected from males of the 5-mg/kg dose group on TD 29 was significantly (P<0.05, pair-wise t test with Bonferroni's correction) higher than on TD 15.
In the affected males (4/5), sperm were absent from the tubular lumina of the initial segment and caput and scant in the proximal cauda. No lesions were observed in the epididymides of males of the 1- and 5-mg/kg dose groups. The concentration of sperm in the 4-mL "swim-out" was depressed in the 25-mg/kg dose group. The mean concentrations of epididymal sperm in this dose group were 61% and 36% of the control mean for TD 15 and 29, respectively. On TD 15 sperm motion characteristics were profoundly altered in the 5-and 25-mg/kg dose groups. The percentage of motile sperm was depressed in both the 5-and 25-mg/kg dose groups. However, the percentage of motile sperm collected from males of the 5-mg/kg dose group on TD 29 was significantly (P<0.05, pair-wise t test with Bonferroni's correction) higher than on TD 15.

Any other information on results incl. tables

On TD 15, the most pronounced effect was the increase in testicular weight (attributed to edema).

On TD 29 (2 weeks after treatment was terminated), alterations in DNA ploidy ratios were more evident as were morphologic changes in the germinal epithelium. The decrease in percentage of haploid cells in the tested from rats from the 25 mg/kg dosed group suggested that sperm production was compromised.

Effects on sperm motion were visibly apparent on TD15 and measurable at the 5 and 25 mg/kg dose levels. The parameters that differed significantly from the control group at both 5 and 25 mg/kg dose levels were percent motile and percent progressively motile. Both parameters are clearly associated with the reversible antifertility effect of the substance. Doses of 25 mg/kg bw/d resulted in an increase in the percentage of tailless sperm. It is suggested by the authors that the effect is primarily posttesticular.

The usefullness of the mating component in this study is evaluated as limited.

Applicant's summary and conclusion

Conclusions:

[Alpha]-chlorohydrin was administered orally by gavage to male rats at doses of 0, 1, 5 or 25 mg/kg bw/d for 14 days.
Testicular and epididymal lesions occured at 25 mg/kg bw/d. DNA ploidy distributions were predictive of testicular damage, with effects more pronounced on TD 29 than on TD 15.
Sperm motion was altered at the 5 and 25 mg/kg dose levels on TD15. The percentage of motile sperm and the percentage of progressively motile sperm were markedly depressed at both the 5 and 25 mg/kg dose levels where antifertility effects occurred. Sperm velocities and amplitude of lateral head displacement were depressed at the 25 mg/kg dose level on both TD 15 and 29. Additionally, decreased epidymal sperm concentrations and increased breakage were recorded at this dose level.