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Study Information
Study Attribute Value
CEBS Accession Number: 002-02417-0010-0000-7
Chemical Name: Methapyrilene hydrochloride
CASRN: 135-23-9
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: 860299
Study Result: Negative


Table Instructions and Notes:
Studies are indicated to be "Nontoxic" when the observed reductions in relative total growth did not indicate that the maximum tolerated dose was achieved.

Nonactivation Trial: 1 Experiment Call: Negative
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Water 
 0         
 68 69 192 94 73
    105 107 211 67
    100 114 195 65
    93 109 188 67
Test Chemical Methapyrilene hydrochloride 
50         
 88 77 191 72 76
    90 74 213 79
  
100         
 64 59 195 102 100
    78 62 229 98
  
200         
 65 37 241 124 121*
    68 42 238 117
  
300         
 87 35 185 71 96
    51 20 183 120
  
400         
   
Positive Control Methyl Methane Sulfonate 
15         
 26 16 438 551 406*
    47 27 368 262

Nonactivation Trial: 2 Experiment Call: Negative
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Water 
 0         
 68 94 89 44 46
    82 92 108 44
    71 109 85 40
    65 105 109 56
Test Chemical Methapyrilene hydrochloride 
100         
 56 64 106 63 53
    65 79 84 43
  
200         
 54 51 98 61 58
    55 54 90 55
  
300         
 54 39 98 60 61
    49 36 92 62
  
400         
   
Positive Control Methyl Methane Sulfonate 
15         
 36 29 130 120 121*
    43 33 154 121

Induced S9 Trial: 1 Experiment Call: Negative
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Water 
 0         
 69 100 48 23 24
    76 97 46 20
    79 98 68 29
    77 105 52 23
Test Chemical Methapyrilene hydrochloride 
100         
 68 98 54 27 30
    93 97 90 32
  
200         
 57 70 67 39 35
    72 84 68 31
  
300         
 80 84 82 34 39*
    74 67 97 44
  
400         
 97 67 88 30 32
    88 65 90 34
  
500         
 99 39 95 32 36
    79 55 95 40
Positive Control 3-Methylcholanthrene 
2.5       
 49 26 519 353 355*
    55 26 592 357

Induced S9 Trial: 2 Experiment Call: Negative
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Water 
 0         
 83 105 89 36 42
    75 99 105 47
    79 109 98 41
    74 88 103 46
Test Chemical Methapyrilene hydrochloride 
150         
 52 54 104 66 42
    53 57 27 17
  
250         
 63 45 40 21 22
    67 64 44 22
  
350         
 64 38 59 31 36
    65 40 78 40
  
450         
 69 33 48 23 27
    63 28 57 30
  
550         
 49 5 43 29 28
    63 12 50 26
  
650         
   
Positive Control 3-Methylcholanthrene 
2.5       
 71 66 381 180 197*
    72 53 463 213

Footnotes:
Asterisks(*) indicate significant responses.
r = rejected value due to quality control criteria
# = reduced sample size because of the loss of one culture dish due to contamination