p-nonylphenol

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from peer reviewed journal

Data source

Reference

Reference Type:

publication

Title:

Maternal and offspring toxicity but few sexually dimorphic behavioral alterations result from nonylphenol exposure

Author:

Sherry A. Ferguson, Katherine M. Flynn, K. Barry Delclos, Retha R. Newbold

Year:

2000

Bibliographic source:

Neurotoxicology and Teratology 22 (2000) 583–591

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: refer below principle

Principles of method if other than guideline:

Study access to determine the developmental effects of test substance p-nonylphenol

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

p-nonylphenol

EC Number:

203-199-4

EC Name:

p-nonylphenol

Cas Number:

104-40-5

Molecular formula:

C15H24O

IUPAC Name:

4-nonylphenol

Test material form:

liquid: viscous

Details on test material:

- Name of test material (as cited in study report): p-nonylphenol
- Molecular formula (if other than submission substance): C15-H24-O
- Molecular weight (if other than submission substance): 220.354
- Smiles notation (if other than submission substance): c1(ccc(O)cc1)CCCCCCCCC
- InChl (if other than submission substance): 1S/C15H24O/c1-2-3-4-5-6-7-8-9-14-10-12-15(16)13-11-14/h10-13,16H,2-9H2,1H3
- Substance type: Organic
- Physical state: viscous liquid

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: National Center for Toxicological Research (NCTR)
- Age at study initiation: Pregnant rats
- Weight at study initiation: exact weight was not mention but all treatment groups had approximately equal body weights
- Fasting period before study: No data available
- Housing: individually in a standard polycarbonate tub cage lined with wood chip bedding.
- Diet (e.g. ad libitum): NIH-31 diets ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: No data available

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 ± 3°C
- Humidity (%): 50 ± 10%.
- Air changes (per hr): No data available
- Photoperiod (hrs dark / hrs light): 12:12-h light-dark cycle

IN-LIFE DATES: From: To: No data available

Administration / exposure

Route of administration:

oral: feed

Type of inhalation exposure (if applicable):

not specified

Vehicle:

other: Diet

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: diet is based on the NIH-31 formula, except that case in replaces the protein contributed by soy and alfalfa, soy oil is replaced by corn oil, and the vitamin mix is adjusted for irradiation.

DIET PREPARATION
- Rate of preparation of diet (frequency): No data available
- Mixing appropriate amounts with (Type of food): NP was mixed into the standard 5K96 feed by the Diet Preparation Staff.
- Storage temperature of food: No data available

VEHICLE
- Justification for use and choice of vehicle (if other than water): No data available
- Concentration in vehicle: No data available
- Amount of vehicle (if gavage): No data available
- Lot/batch no. (if required): No data available
- Purity: No data available

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

HPLC analytical methods

Details on mating procedure:

- Proof of pregnancy: sperm plug date is GD 0

Duration of treatment / exposure:

No data

Frequency of treatment:

Daily

Duration of test:

From GD(gestational day) 0 to PND(postnatal day) 77

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 1.25 ,25 ,100 mg/kg
Basis:
no data

No. of animals per sex per dose:

0- (n= 11),
1.25 - (n= 10),
25- (n= 10),
100- (n= 9)

Control animals:

not specified

Details on study design:

- Dose selection rationale: These doses were chosen with the goal of choosing a high dose that alters the reproductive tract or other estrogen-sensitive organs of the offspring while causing only minimal maternal toxicity or other overt fetal toxicity.

- Rationale for animal assignment (if not random): no data available

Examinations

Ovaries and uterine content:

Body weight and food intake: Body weight and food intake were measured weekly for each dam on GDs 1, 7, 14, and 21 and on PNDs 8, 15, and 21. Total weight gain during pregnancy was calculated by subtracting the GD 1 body weight measurement from the GD 21 measurement.

Fetal examinations:

Individual offspring weights were measured
on PNDs 2, 8, 15, 21, 28, 42, 56, 70, and 77.

Food intake was measured weekly after weaning.
Play behavior
Male and female pair 1 were assessed for play behavior.

open-field activity
PNDs 64–66 open-field activity, and flavored solution
intake. Male and female pair 3 were assessed for
PNDs 22–24 open-field activity.

Residential running wheel activity: one male and one female from each litter were housed individually with a residential running wheel.

Intake of flavored solutions: intake of two flavored solutions was determined in one male and one female from each litter. Animals were individually housed throughout this test period. Intake of a sweet solution containing 0.3% saccharin in water was measured on PNDs 69 to 71 by placing two bottles on each subject’s cage, one containing only water and the other containing the saccharin solution. Intake of a salt solution containing 3.0% sodium chloride.

Statistics:

Post hoc tests (two-sided Dunnett’s or Student’s– Newman–Keuls

Indices:

No data available

Historical control data:

No data available

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Physical measures:
Dams and litters: there were no significant effects of NP exposure on gestation duration or dam body weight during pregnancy and lactation, although dams in the 2,000-ppm group gained 17% less during GDs 1 to 21 than control dams. However, there was a significant treatment effect on dam food consumption. Post hoc testsindicated that dams in the 25-, 500-, and 2,000-ppm groups consumed significantly less food than control dams.

Body weight: There were no significant effects of NP exposure on gestation duration or dam body weight during pregnancy and lactation although dams in the 2,000-ppm group gained 17% less during GDs 1 to 21 than control dams. Post hoc tests indicated that dams in the 1.25 ,25 ,100 mg/kg groups consumed significantly less food than control dams.

Effect levels (maternal animals)

Dose descriptor:

LOEL

Effect level:

1.25 mg/kg diet

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
Physical measures:
Dams and litters: Sex ratio of live pups, and number of live or dead pups per litter did not differ significantly as a result of NP exposure.

Body weight: Post hoc tests indicated that males in the 2,000-ppm group weighed significantly less than same-sex controls beginning at PND 28 and continuing through the end of the study at PND 77. Similar to male offspring, however, females in the 2,000-ppm group weighed significantly less than control females beginning on PND 28 and continuing through PND 77.

Food consumption: Offspring in the 2,000-ppm group
consumed less than the control group at all ages. Offspring
in the 25-ppm group consumed less than controls on the
week of PNDs 50 to 56. The decrease in food consumption
in all groups that occurred PNDs 64 to 77 is likely related to the fact that on PND 63, animals were individually housed rather than housed with a same-sex sibling.

Behavioral assessments:
Open-field activity: There were no statistically significant treatment-related effects in the analysis of PNDs 43 to 45 open-field behavior. At PNDs 65 to 67, there was a significant interaction of sex by NP treatment on total activity and post hoc comparisons indicated that females
in the 500-ppm group were less active than same-sex
controls.
Females of 25-ppm group are more active than
control females. Females of 500-ppm group are less active than control females.

Play behavior: There were no significant effects of NP treatment on frequency of pinning behavior.

Residential running wheel activity: Females were more active than males on all nights and days. There were no significant effects of NP treatment on day (light period) activity (data not shown) or night (dark period) activity.

Intake of flavored solutions:
There were significant effects of NP treatment and sex on intake of the sodium solution. The sex effect indicated that females consumed approximately 1.5 times the amount of the salt solution as males. Post hoc tests of the significant NP treatment effect indicated that only the 2,000-ppm group was significantly different from controls, consuming more of the sodium solution.

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

The endpoint for the developmental toxicity was found to be LOEL at 1.25 mg/kg to rats when treated p- nonylphenol (104-40-5).

Executive summary:

Developmental toxicity was performed on rats by given treatment of p-nonylphenol from from GD(gestational day) 0 to PND(postnatal day) 77 with different concentrations 0, 1.25 ,25 ,100 mg/kg having n=11, n=10, n=10 and n=9.

Each dam was housed individually in a standard polycarbonate tub cage lined with wood chip bedding. Food and water were provided ad libitum.Two weeks prior to mating, dams were shifted from the standard autoclaved NIH-31 pellet diet to an irradiated soy and

alfalfa-free powdered diet.NP was mixed into the standard 5K96 feed by the Diet Preparation Staff.

Body weight and food intake were measured weekly for each dam on GDs 1, 7, 14, and 21 and on PNDs 8, 15, and 21 days.Individual offspring weights were measured on PNDs 2, 8, 15, 21, 28, 42, 56, 70, and 77.Behavioral assessments of offspring were done includes Open-field activity,Play behavior, Residential running wheel activity, Intake of flavored solutions.

There were no significant effects of NP exposure on gestation duration or dam body weight during pregnancy and lactation , although dams in the 2,000-ppm group gained 17% less during GDs 1 to 21 than control dams. However, there was a significant treatment effect on dam food consumption .Post hoc tests indicated that dams in the 25-, 500-, and 2,000-ppm groups consumed significantly less food than control dams. Post hoc tests indicated that males in the 2,000- ppm group weighed significantly less than same-sex controls beginning at PND 28 and continuing through the end of the study at PND 77. Males in the two lower NP dose groups were affected less severely: those in the 500-ppm group weighed significantly less on PNDs 56 to 77 and those in the 25-ppm group weighed significantly less on PND 72 only.Body weights of female offspring in the 25- and 500-ppm groups were not significantly different from control females at any time.

Offspring in the 25-ppm group consumed less than controls on the week of PNDs 50 to 56. The decrease in food consumption in all groups that occurred PNDs 64 to 77 is likely related to the fact that on PND 63, animals were individually housed rather than housed with a same-sex sibling.

No treated group was significantly different from control in offspring behavioral assessments. So on the basis of decreased food intake and weight gain it was found thattheendpoint for the developmental toxicity was found to be LOEL at 1.25 mg/kg to rats when treated p- nonylphenol (104-40-5).