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Study Information
Study Attribute Value
CEBS Accession Number: 002-01525-0014-0000-0
Chemical Name: 5,5-Diphenylhydantoin (phenytoin)
CASRN: 57-41-0
NTP Study Type: Genetic Toxicology - Rodent Cytogenetics
NTP Study ID: 252423_CA
Study Result: Negative


Table Instructions and Notes:

Below are the detailed Chromosome Abberation data. You may also view the summary data for this study.


Initial Treatment Date Tissue Sample Time (h) Sex Species Strain Protocol Result
04/04/1985 Bone Marrow 17 Male Mouse B6C3F1 Intraperitoneal Injection x 1/study, 17 hour Negative

  Dose
(mg/kg)		 Animal
Number		 No.
Cells		 Chromatid Isochromatid Exchanges Aberrations
Breaks Gaps Breaks Gaps 'Tid 'Some Other Total Per Cell % Cells w/ Abs
(+ Gaps) (- Gaps) (+ Gaps) (- Gaps)
Positive Control Dimethylbenzanthracene 
100         
 2073 50 5 8 1 0 0 0 0 14 0.28 0.12 20.00 10.00
    2075 50 6 10 0 1 0 0 0 17 0.34 0.12 20.00 8.00
    2076 50 5 3 0 0 0 0 0 8 0.16 0.10 12.00 6.00
    2077 50 1 2 0 0 0 0 0 3 0.06 0.02 6.00 2.00
    2080 50 3 3 0 0 0 0 0 6 0.12 0.06 10.00 6.00
    2082 50 5 8 0 0 0 0 0 13 0.26 0.10 14.00 8.00
    2092 50 0 3 0 0 0 0 0 3 0.06 0.00 6.00 0.00
    2101 50 7 1 0 0 0 0 0 8 0.16 0.14 14.00 12.00
Average         4.0 4.8 0.1 0.1 0.0 0.0 0.0 9.0 0.18 0.08 12.75 6.50
± SEM                         0.04 0.02 1.92 1.40
 
Test Chemical 5,5-Diphenylhydantoin (phenytoin) 
125         
 2074 50 1 0 0 0 0 0 0 1 0.02 0.02 2.00 2.00
    2079 50 1 1 0 0 0 0 0 2 0.04 0.02 4.00 2.00
    2083 50 0 1 0 0 0 0 0 1 0.02 0.00 2.00 0.00
    2087 50 0 0 0 0 0 0 0 0 0.00 0.00 0.00 0.00
    2118 50 0 1 0 0 0 0 0 1 0.02 0.00 2.00 0.00
    2119 50 0 0 0 0 0 0 0 0 0.00 0.00 0.00 0.00
    2120 50 1 2 0 0 0 0 0 3 0.06 0.02 6.00 2.00
    2121 50 0 1 0 0 0 0 0 1 0.02 0.00 2.00 0.00
Average         0.4 0.8 0.0 0.0 0.0 0.0 0.0 1.1 0.02 0.01 2.25 0.75
± SEM                         0.01 0.00 0.70 0.37
 
Test Chemical 5,5-Diphenylhydantoin (phenytoin) 
250         
 2078 50 0 0 0 0 0 0 0 0 0.00 0.00 0.00 0.00
    2091 50 0 1 0 0 0 0 0 1 0.02 0.00 2.00 0.00
    2097 50 1 0 0 0 0 0 0 1 0.02 0.02 2.00 2.00
    2098 50 1 1 0 0 0 0 0 2 0.04 0.02 4.00 2.00
    2099 50 0 0 0 0 0 0 0 0 0.00 0.00 0.00 0.00
    2103 50 1 1 0 0 0 0 0 2 0.04 0.02 4.00 2.00
    2108 50 0 0 0 0 0 0 0 0 0.00 0.00 0.00 0.00
    2114 50 0 2 0 0 0 0 0 2 0.04 0.00 4.00 0.00
Average         0.4 0.6 0.0 0.0 0.0 0.0 0.0 1.0 0.02 0.01 2.00 0.75
± SEM                         0.01 0.00 0.65 0.37
 
Test Chemical 5,5-Diphenylhydantoin (phenytoin) 
500         
 2084 50 0 0 0 0 0 0 0 0 0.00 0.00 0.00 0.00
    2089 50 0 0 0 0 0 0 1 1 0.02 0.02 2.00 2.00
    2090 50 0 1 0 0 0 0 0 1 0.02 0.00 2.00 0.00
    2102 50 1 0 0 0 0 0 0 1 0.02 0.02 2.00 2.00
    2105 50 2 0 0 0 0 0 0 2 0.04 0.04 4.00 4.00
    2107 50 0 1 0 0 0 0 2 3 0.06 0.04 2.00 0.00
    2109 50 1 0 0 0 0 0 1 2 0.04 0.04 4.00 4.00
    2110 50 0 1 0 0 0 0 0 1 0.02 0.00 4.00 2.00
Average         0.5 0.4 0.0 0.0 0.0 0.0 0.5 1.4 0.03 0.02 2.50 1.75
± SEM                         0.01 0.01 0.50 0.59
 
Vehicle Control No Stressor 
 0         
 2086 50 0 1 0 0 0 0 0 1 0.02 0.00 2.00 0.00
    2094 50 1 1 1 0 0 0 0 3 0.06 0.04 6.00 4.00
    2096 50 0 1 0 0 0 0 0 1 0.02 0.00 2.00 0.00
    2100 50 0 0 0 0 0 0 1 1 0.02 0.02 0.00 0.00
    2104 50 2 0 0 0 0 0 0 2 0.04 0.04 4.00 4.00
    2111 50 0 1 0 0 0 0 0 1 0.02 0.00 2.00 0.00
    2112 50 0 2 0 0 0 0 0 2 0.04 0.00 4.00 0.00
    2115 50 1 2 0 0 0 0 0 3 0.06 0.02 6.00 2.00
Average         0.5 1.0 0.1 0.0 0.0 0.0 0.1 1.8 0.04 0.02 3.25 1.25
± SEM                         0.01 0.01 0.75 0.65
 
Footnotes:
CRO: Corn Oil
DMBA: Dimethylbenzanthracene
IP/IJ: Intraperitoneal injection
INHAL: Inhalation