FIELD T-l 

 Column 57 



administered alone (only slightly more than 40%, in the foregoing illustration), 

 Field Y is coded with Symbol 3. Otherwise (42% through 49%, in the foregoing 

 example), Field Y is coded with Symbol 0. Finally, in the event that response 

 intensity should be only exactly equal to that of the most active of the compounds 

 when administered alone (exactly 40%, in the foregoing illustration), Field T-l 

 should be coded with either Symbol C or Symbol 9 and Field Y should be coded 

 with Symbol 1 (with Criterion 01 coded in Field X) to indicate that the additive 

 or antagonistic effect did not occur. Field T-l need not be double coded nor 

 two lines prepared in this case, because by coding the fact that one (C or 9) 

 occurred, it is implicit that the other (9 or C) did not occur. 



B. The test compound depresses the intensity of the organism's response to the secondary 

 compound, as compared to the intensity of response when the secondary compound is 

 administered alone. 



I. Specific action and intensity of action of each compound (of the two compounds 

 involved), when it is administered alone, is KNOWN. (See Figures 1 and 3. ) 



If the intensity of action of the secondary compound when administered alone is known 

 and the intensity of action of the test compound when administered alone is also known, 

 it can be determined (when the two are administered together, each in the same quantity 

 as when it was administered alone) whether the test compound's influence is one of 

 antagonism to the secondary compound's action (Symbol 9). Antagonism of a secondary 

 compound's action may be by a test compound which, when administered alone, performs 

 the same action (though not to the same degree) as the secondary compound (e. g. , both 

 increase or both decrease the biological state or physiological process coded in 

 Field T-2) or the antagonism may be by a test compound which, when administered alone, 

 performs the opposing action (one compound increases and the other decreases the 

 biological state or physiological process coded in Field T-2, when administered 

 alone). Antagonism is described below (1 and 2) for each of these situations. 



(1) Antagonism, when the test compound and secondary compound produce opposing 

 responses when administered alone. (See Figure 3. ) If, when administered 

 together, the response is the same as when the secondary compound was admin- 

 istered alone, but at a lower intensity , the effect of the test compound is coded 

 as antagonism; also, if no response occurs when the two are administered to- 

 gether or even if a response occurs opposite to that made to the secondary 

 compound when administered alone, the effect of the test compound is coded 



as antagonism. 



Note: In reference to the last- mentioned circumstance (when the response to 

 the two compounds administered together opposes the response to the secondary 

 compound when administered alone), the results should be coded as antagonism 

 of the secondary compound as long as the intensity of that opposing response 

 is equal to or less than the intensity of response to the test compound when 

 administered alone. However, when the intensity of that response opposing the 

 secondary compound's is greater than the intensity of response to the test 

 compound when the test compound is administered alone, a second code sheet 

 should always be prepared on which a code line is constructed whereby the 

 secondary compound of the first line is coded as the test compound synergizing 

 the action of the compound coded in the first line as the test compound. This 

 is indicated by Figure 3. 



(2) Antagonism, when the test compound and secondary compound cause the same 

 response but in different intensities when administered alone or when the test 

 compound did not affect the biological state or physiological process of Field 

 T-2 when administered alone . (See Figure 1. ) If the intensity of response, 

 when the compounds are administered together, is less than the intensity of 

 response to the secondary compound when administered alone, the effect of the 

 test compound is coded as antagonism. 



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