Hexylamine

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study Please refer to section 13 (read across statement).

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OTS 798.5395 (In Vivo Mammalian Cytogenics Tests: Erythrocyte Micronucleus Assay)

Deviations:

no

GLP compliance:

yes

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

Butylamine

EC Number:

203-699-2

EC Name:

Butylamine

Cas Number:

109-73-9

IUPAC Name:

butan-1-amine

Test animals

Species:

mouse

Strain:

ICR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Sprague Dawley, Inc., MD
- Age at study initiation: 6 - 8 weeks
- Weight at study initiation: 25 - 33 g (m); 24 - 33 (f)
- Assigned to test groups randomly: yes
- Fasting period before study:
- Housing: 5/cage/sex
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: >= 5 d


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 +-3 °C (74 +-6 °F)
- Humidity (%): 50 +-20
- Photoperiod (hrs dark / hrs light): 12 / 12


IN-LIFE DATES: From: To:

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

Distilled water

Details on exposure:

Dosage volume: 20 mL/kg bw

Duration of treatment / exposure:

24, 48, and 72 h post-application

Frequency of treatment:

1x

Doses / concentrations

Remarks:

Doses / Concentrations:
125, 250, and 500 mg/kg bw
Basis:
other: 6.25, 12.5, and 25 mg/mL, dose volume 20 mL/kg bw

No. of animals per sex per dose:

15 (5 per time interval per sex)

Control animals:

yes, concurrent vehicle

Positive control(s):

Cyclophosphamide, 40 mg/kg bw (oral, gavage)

Examinations

Tissues and cell types examined:

Bone-marrow from femurs, polychromatic erythrocytes (PE), normocytes (NE)

EXAMINATIONS:  
- Clinical observations: after dose administration  
- Number of micronucleated polychromatic erythrocytes per 1000 PCE  
- The proportion of polychromatic erythrocytes to total erythrocytes  

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION:
prior toxicity testing/range finding


TREATMENT AND SAMPLING TIMES: 1x dosing / 3x sampling 24, 48, and 72 h p.a.


DETAILS OF SLIDE PREPARATION: air-drying, fixing in methanol, staining with May-Grünwald-Giemsa cocktail


METHOD OF ANALYSIS: Light microscopy

Evaluation criteria:

Validity:
The mean incidence of micronucleated PCE (MPCE) must not exceed 5/1000 PCE (0.5 %) in the negative (vehicle) control.
The incidence of micronucleated PCE (MPCE) in the positive control must be significantly increased relative to the neg. control (p =<0.05).

Determinations in test groups:
Incidence of MPCE; proportion of PCE to total erythrocytes (impact on erythropoiesis) in each animal and group:
- positive response when there is a dose-response and one or more doses result in significant increases above neg. control.
- questionable when a single treatment results in a significant increase with no evidence of dose-response.
- negative when no significant increase is seen above the neg. control.

Statistics:

Kastenbaum-Bowman tables (binominal distribution) for significance of differences from neg. control

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

yes

Remarks:

Mortality of males at 72 h

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

RESULTS OF RANGE-FINDING STUDY
- Dose range for acute toxicity: 50 - 1500 mg/kg bw
- Solubility: miscible
- Clinical signs of toxicity in test animals: lethargy, prostration, mortality
- Result: LD50/3 = approx. 500 mg/kg bw, selected as upper dose level

RESULTS OF DEFINITIVE STUDY
- Induction of micronuclei (for Micronucleus assay): no increase
- Ratio of PCE/NCE: Maximum reduction of 44 % in the male animals of 500 mg/kg at 48-h treatment time. All other PCE/NCE ratios were less than 30 % compared to the respective vehicle animals.
- Appropriateness of dose levels and route: Highest dose causing treatment-related mortality,
reduction in the ratio of PCE/total erys =<44% indicating bioavailability at the target tissue.

Any other information on results incl. tables

Summary of the bone-marrow study with n-butylamine in ICR mice (from Report, Table 2)

Dose [mg/kg]	Sex	Time [h]	Animal number [m / f]	Ratio PCE/total Erys [m / f]	Ratio MPCE/5000 Erys scored [m / f]
Water	m / f	24	5 / 5	0.57 / 0.53	2 / 0
		48	5 / 5	0.52 / 0.49	3 / 2
		72	5 / 5	0.53 / 0.61	3 / 4
125	m / f	24	5 / 5	0.51 / 0.42	1 / 1
		48	5 / 5	0.48 / 0.52	1 / 4
		72	5 / 5	0.43 / 0.64	5 / 7
250	m / f	24	5 / 5	0.52 / 0.51	0 / 1
		48	5 / 5	0.52 / 0.46	3 / 4
		72	5 / 5	0.47 / 0.62	3 / 0
500	m / f	24	5 / 5	0.45 / 0.48	0 / 0
		48	4/ 5	0.29 / 0.35	~1 / 3
		72	0^+ / 5	-- / 0.53	- / 5
CP [40]	m / f	24	5 / 5	0.42 / 0.54	71 / 92*

EFFECT ON PCE/NCE RATIO: Maximum reduction of 44 % in the male animals of 500 mg/kg at 48-h treatment time.  All other PCE/NCE ratios were less than 30 % compared to the respective vehicle animals. GENOTOXIC EFFECTS: Not clastogenic MPCE FREQUENCY: No statistically significant increase in the number of micronucleated polychromatic erythrocytes per 1000 polychromatic erythrocytes relative to their respective vehicle controls.