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Study Information
Study Attribute Value
CEBS Accession Number: 002-02732-0001-0000-7
Chemical Name: Primidone (primaclone)
CASRN: 125-33-7
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 945872_SCE
Study Result: Negative

Study Result: Negative
Activation Trial Trial Call
No Activation  1  Negative 
Induced Rat Liver S9  1_S9  Negative 

Trial #: 1    Activation: No Activation    Date: 04/06/1989    Trial Call: Negative   
  Dose
µg/mL		 Number
Cells
Examined		 Number
Chromosomes
Examined		 Total
Number
SCEs		 SCE /
Chromosome		 SCE /
Cell		 Hours in
BRDU		 % Increase
Over Solvent
Control
Vehicle Control Dimethyl Sulfoxide 
0         
 50 1048 365 0.348 7.30 26.0 -12.470
Dimethyl Sulfoxide 
0         
 50 1048 417 0.398 8.34 31.0 0.000
Test Chemical Primidone (primaclone) 
125         
 50 1048 411 0.392 8.22 26.0 -1.439 
417         
 50 1048 416 0.397 8.32 31.0 -0.240 
1250         
 50 1037 454 0.438 9.08 31.0 10.028
Positive Control Mitomycin-C 
 0.001     
 50 1052 672 0.639 13.44 26.0 60.538
Mitomycin-C 
 0.005     
 10 210 269 1.281 26.90 26.0 221.928
Trend: 1.389        
Probability: 0.082        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 04/06/1989    Trial Call: Negative   
  Dose
µg/mL		 Number
Cells
Examined		 Number
Chromosomes
Examined		 Total
Number
SCEs		 SCE /
Chromosome		 SCE /
Cell		 Hours in
BRDU		 % Increase
Over Solvent
Control
Vehicle Control Negative (Not Specified) 
0         
 50 1046 394 0.377 7.88 26.0 -7.552
Dimethyl Sulfoxide 
0         
 50 1048 427 0.407 8.54 26.0 0.000
Test Chemical Primidone (primaclone) 
125         
 50 1046 457 0.437 9.14 26.0 7.230 
417         
 50 1045 418 0.400 8.36 26.0 -1.827 
1250         
 50 1045 368 0.352 7.36 26.0 -13.570
Positive Control Cyclophosphamide 
 0.125     
 50 1053 567 0.538 11.34 26.0 32.156
Cyclophosphamide 
 0.5       
 10 210 184 0.876 18.40 26.0 115.046
Trend: -2.308        
Probability: 0.989