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Study Information
Study Attribute Value
CEBS Accession Number: 002-02758-0001-0000-5
Chemical Name: Pyrilamine
CASRN: 91-84-9
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 304876_SCE
Study Result: Positive

Study Result: Positive
Activation Trial Trial Call
No Activation  1  Negative 
No Activation  2  Negative 
No Activation  3  Questionable 
Induced Rat Liver S9  1_S9  Weakly Positive 
Induced Rat Liver S9  2_S9  Test Failure 
Induced Rat Liver S9  3_S9  Negative 
Induced Rat Liver S9  4_S9  Positive 
Induced Rat Liver S9  5_S9  Positive 

Trial #: 1    Activation: No Activation    Date: 05/21/1989    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 1046 342 0.327 6.84 26.0 -14.795
Dimethyl Sulfoxide 
0         
 50 1045 401 0.384 8.02 31.0 0.000
Test Chemical Pyrilamine 
5         
 50 1048 433 0.413 8.66 26.0 7.671 
17         
 50 1043 400 0.384 8.00 26.0 -0.058 
50         
 50 1045 429 0.411 8.58 31.0 6.983 
167         
 0 0 0 0.000 0.00 0.0 N/A
Positive Control Mitomycin-C 
 0.001     
 50 1049 620 0.591 12.40 26.0 54.024
Mitomycin-C 
 0.005     
 10 211 278 1.318 27.80 26.0 243.348
Trend: 0.559        
Probability: 0.288        

Trial #: 2    Activation: No Activation    Date: 06/24/1989    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 1046 448 0.428 8.96 31.0 0.000
Negative (Not Specified) 
0         
 50 1049 401 0.382 8.02 31.0 -10.747
Test Chemical Pyrilamine 
5         
 50 1051 415 0.395 8.30 31.0 -7.807 
17         
 50 1049 420 0.400 8.40 31.0 -6.518 
50         
 50 1049 517 0.493 10.34 31.0 15.072 
167         
 0 0 0 0.000 0.00 0.0 N/A
Positive Control Mitomycin-C 
 0.001     
 50 1050 790 0.752 15.80 31.0 75.668
Mitomycin-C 
 0.005     
 10 212 342 1.613 34.20 31.0 276.655
Trend: 2.140        
Probability: 0.016        

Trial #: 3    Activation: No Activation    Date: 12/20/1989    Trial Call: Questionable   
  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 1046 372 0.356 7.44 26.0 0.000
Negative (Not Specified) 
0         
 50 1046 320 0.306 6.40 26.0 -13.978
Test Chemical Pyrilamine 
1.7       
 50 1047 379 0.362 7.58 26.0 1.784 
5         
 50 1044 400 0.383 8.00 26.0 7.733 
17         
 50 1040 437 0.420 8.74 26.0 18.151 
50         
 0 0 0 0.000 0.00 0.0 N/A
Positive Control Mitomycin-C 
 0.001     
 50 1046 608 0.581 12.16 26.0 63.441
Mitomycin-C 
 0.004     
 10 209 192 0.919 19.20 26.0 158.311
Trend: 2.530        
Probability: 0.006        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 05/02/1989    Trial Call: Weakly Positive   
  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 1052 427 0.406 8.54 26.0 -3.978
Dimethyl Sulfoxide 
0         
 50 1048 443 0.423 8.86 31.0 0.000
Test Chemical Pyrilamine 
50         
 50 1053 417 0.396 8.34 26.0 -6.316 
167         
 50 1047 428 0.409 8.56 31.0 -3.294 
500         
 50 1045 537 0.514 10.74 31.0 21.567 
1667         
 0 0 0 0.000 0.00 0.0 N/A
Positive Control Cyclophosphamide 
 0.125     
 50 1047 591 0.564 11.82 26.0 33.536
Cyclophosphamide 
 0.5       
 10 210 196 0.933 19.60 26.0 120.798
Trend: 3.085        
Probability: 0.001        

Trial #: 2_S9    Activation: Induced Rat Liver S9    Date: 06/15/1989    Trial Call: Test Failure   
  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 1050 391 0.372 7.82 26.0 0.000
Negative (Not Specified) 
0         
 50 1050 415 0.395 8.30 26.0 6.138
Test Chemical Pyrilamine 
50         
 50 1048 454 0.433 9.08 26.0 16.334 
167         
 50 1051 509 0.484 10.18 26.0 30.055 
500         
 50 1044 521 0.499 10.42 26.0 34.014 
1667         
 0 0 0 0.000 0.00 0.0 N/A
Positive Control Cyclophosphamide 
 0.125     
 50 1050 563 0.536 11.26 26.0 43.990
Cyclophosphamide 
 0.5       
 10 210 181 0.862 18.10 26.0 131.458
Trend: 4.686        
Probability: 0.000        

Trial #: 3_S9    Activation: Induced Rat Liver S9    Date: 07/25/1989    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 1046 452 0.432 9.04 31.0 0.000
Dimethyl Sulfoxide 
0         
 50 1043 397 0.381 7.94 26.0 -11.916
Test Chemical Pyrilamine 
125         
 50 1045 452 0.433 9.04 26.0 0.096 
250         
 50 1042 452 0.434 9.04 26.0 0.384 
500         
 50 1045 469 0.449 9.38 31.0 3.860 
750         
 0 0 0 0.000 0.00 0.0 N/A
Positive Control Cyclophosphamide 
 0.125     
 50 1044 569 0.545 11.38 26.0 26.126
Cyclophosphamide 
 0.5       
 10 209 205 0.981 20.50 26.0 126.987
Trend: 0.570        
Probability: 0.284        

Trial #: 4_S9    Activation: Induced Rat Liver S9    Date: 12/20/1989    Trial Call: Positive   
  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 1046 388 0.371 7.76 26.0 0.000
Negative (Not Specified) 
0         
 50 1047 371 0.354 7.42 26.0 -4.473
Test Chemical Pyrilamine 
17         
 50 1049 470 0.448 9.40 26.0 20.788 
50         
 50 1046 426 0.407 8.52 26.0 9.794 
167         
 50 1049 537 0.512 10.74 26.0 38.006 
500         
 0 0 0 0.000 0.00 0.0 N/A
Positive Control Cyclophosphamide 
 0.125     
 50 1050 729 0.694 14.58 26.0 87.171
Cyclophosphamide 
 0.5       
 10 210 272 1.295 27.20 26.0 249.180
Trend: 4.250        
Probability: 0.000        

Trial #: 5_S9    Activation: Induced Rat Liver S9    Date: 01/09/1990    Trial Call: Positive   
  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 1047 392 0.374 7.84 26.0 7.016
Dimethyl Sulfoxide 
0         
 50 1049 367 0.350 7.34 26.0 0.000
Test Chemical Pyrilamine 
150         
 50 1044 487 0.466 9.74 26.0 33.333 
200         
 50 1045 518 0.496 10.36 26.0 41.685 
250         
 50 1041 556 0.534 11.12 26.0 52.663
Positive Control Cyclophosphamide 
 0.125     
 50 1047 498 0.476 9.96 26.0 35.954
Cyclophosphamide 
 0.5       
 10 210 195 0.929 19.50 26.0 165.415
Trend: 6.205        
Probability: 0.000