Registration Dossier

Administrative data

Endpoint:
behavioural effects
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: This study is classified as reliable with restrictions because there are no statements indicating if the study was conducted according to GLPs or other accepted guidelines.

Data source

Reference
Reference Type:
publication
Title:
Behavioral toxicology of volatile organic solvents v. comparisons of the behavioral and neuroendocrine effects among n-alkanes
Author:
Glowa, J.R.
Year:
1991
Bibliographic source:
Journal of the American College of Toxicology 10(6):639-646

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
The test substance was tested for its ability to impair performance and stimulate hypothalamic-pituitary activity in mice. Performance was assessed using operant responding maintained under a fixed interval 60-sec schedule of milk presentation. Exposure duration was based on time the mice needed to complete the milk-presentation series. Cumulative concentration-effect functions for the test substance were obtained by incrementally increasing exposure concentrations until responding was abolished. Recovery from these rate-decreasing effects was determined 30 min after exposure to the highest concentration.
GLP compliance:
not specified
Type of method:
in vivo
Endpoint addressed:
neurotoxicity

Test material

Constituent 1
Chemical structure
Reference substance name:
Pentane
EC Number:
203-692-4
EC Name:
Pentane
Cas Number:
109-66-0
Molecular formula:
C5H12
IUPAC Name:
pentane

Test animals

Species:
mouse
Strain:
CD-1
Sex:
male

Results and discussion

Details on results:
Concentrations of less than 10,000 ppm n-pentane slightly increased responding. Larger concentrations decreased responding in a concentration-related manner, with 30,000 and 56,000 ppm decreasing responding approximately 50% and 100%, respectively. Responding recovered fully 30 min following the removal of 56,000 ppm pentane. Serum adrenocorticotropin hormone (ACTH) levels increased in a dose-dependent manner; ACTH release is related to hypothalamic-pituitary axis activity. The concentration expected to decrease responding 10% In 1 out of 10, 1 out of 100, and 1 out of 1000 such experiments was calculated to be 10,226; 4057; and 1429, respectively, and the mean (In) concentration to result in a 50% (EC50) and 10% (EC10) decrement in responding was 36,130 +/- 9531 and 26,553 +/- 12,980, respectively.

Applicant's summary and conclusion

Conclusions:
Concentrations of less than 10,000 ppm n-pentane slightly increased responding. Larger concentrations decreased responding in a concentration-related manner, with 30,000 and 56,000 ppm decreasing responding approximately 50% and 100%, respectively. Responding recovered fully 30 min following the removal of 56,000 ppm pentane. Serum adrenocorticotropin hormone (ACTH) levels increased in a dose-dependent manner; ACTH release is related to hypothalamic-pituitary axis activity. The concentration expected to decrease responding 10% In 1 out of 10, 1 out of 100, and 1 out of 1000 such experiments was calculated to be 10,226; 4057; and 1429, respectively, and the mean (In) concentration to result in a 50% (EC50) and 10% (EC10) decrement in responding was 36,130 +/- 9531 and 26,553 +/- 12,980, respectively.
Executive summary:

In a neurotoxicity study, n-pentane was administered to 8 adult male CD-1 mice/concentration by dynamic whole body exposure at five concentrations, in order to assess the effect of the test substance on response time.

 

No mortality or signs of systemic toxicity were reported. The LOAEL and NOAEL were not reported. The concentration expected to decrease responding 10% In 1 out of 10, 1 out of 100, and 1 out of 1000 such experiments was calculated to be 10,226; 4057; and 1429, respectively, and the mean (In) concentration to result in a 50% (EC50) and 10% (EC10) decrement in responding was 36,130 +/- 9531 and 26,553 +/- 12,980, respectively.

 

This study received a Klimisch score of 2 and is classified as reliable with restrictions because there are no statements indicating if the study was conducted according to GLPs or other accepted guidelines.