The Interaction of Carcinogenic Hydrocarbons with Tissues VI. Studies on Zero-Time Binding to Proteins*

A comparison has been made of the methods used for homogenizing and processing tissues in hydrocarbon-skin protein binding studies. The procedure of choice is to use a glass homogenizer cooled in ice and to precipitate the proteins with acetone. The zerotime binding of a number of hydrocarbons has been studied and has been found to be negligible. The zero-time binding of several derivatives of 1,~,5,6-dibenzanthracene has been studied, and in general they bind much more than the parent hydrocarbon, especially ~-phenylphenanthrene-3,~'-dialdehyde, which is not carcinogenic. An at tempt was made to find out whether this compound is a metabolite of 1,~,5,6-dibenzanthracene in mouse skin in vivo. Only negligible amounts could be detected. The significance of these results for the hypothesis that the formation of a tissue-carcinogen complex is an early step in carcinogenesis is discussed.