Government Funding Lapse

Because of a lapse in government funding, the information on this website may not be up to date, transactions submitted via the website may not be processed, and the agency may not be able to respond to inquiries until appropriations are enacted. The NIH Clinical Center (the research hospital of NIH) is open. For more details about its operating status, please visit  cc.nih.gov. Updates regarding government operating status and resumption of normal operations can be found at opm.gov.

U.S. flag

An official website of the United States government

Dot gov

The .gov means it's official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Study Information
Study Attribute Value
CEBS Accession Number: 002-02343-0002-0000-6
Chemical Name: L-Tryptophan
CASRN: 73-22-3
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 702434_CA
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: 03/19/1986    Harvest Time: 13 hour(s)   Trial Call: Negative   
  Dose
µg/mL		 Total
Cells Examined		 Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs
Vehicle Control: Medium 
0         
 200 4 0.020 1.5 1 0.005 0.5 3 0.015 0.5 0 0.000 0.0
Test Chemical: L-Tryptophan 
300         
 200 1 0.005 0.5 0 0.000 0.0 1 0.005 0.5 0 0.000 0.0 
500         
 200 2 0.010 1.0 1 0.005 0.5 1 0.005 0.5 0 0.000 0.0 
1000         
 200 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
Positive Control: Mitomycin-C 
 0.125     
 200 42 0.210 16.0 14 0.070 6.0 28 0.140 11.5 0 0.000 0.0
Mitomycin-C 
 0.25      
 50 21 0.420 40.0 11 0.220 22.0 10 0.200 20.0 0 0.000 0.0
Trend: -1.514 -0.691 -0.807  
Probability: 0.935 0.755 0.790  


Trial #:1_S9   Activation: Induced Rat Liver S9    Date: 04/16/1986    Harvest Time: 13 hour(s)   Trial Call: Negative   
  Dose
µg/mL		 Total
Cells Examined		 Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs
Vehicle Control: Medium 
0         
 200 3 0.015 1.5 0 0.000 0.0 3 0.015 1.5 0 0.000 0.0
Test Chemical: L-Tryptophan 
300         
 200 5 0.025 2.5 1 0.005 0.5 4 0.020 2.0 0 0.000 0.0 
500         
 200 1 0.005 0.5 0 0.000 0.0 1 0.005 0.5 0 0.000 0.0 
1000         
 200 2 0.010 1.0 0 0.000 0.0 2 0.010 1.0 0 0.000 0.0
Positive Control: Cyclophosphamide 
2.5       
 200 20 0.100 9.5 6 0.030 2.5 14 0.070 7.0 0 0.000 0.0
Cyclophosphamide 
7.5       
 50 26 0.520 42.0 6 0.120 12.0 20 0.400 34.0 0 0.000 0.0
Trend: -0.891 -0.419 -0.800  
Probability: 0.813 0.662 0.788