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 zero-time binding of a number of hydrocarbons has been studied and has been found to be negligible. The zero-time binding of several derivatives of 1,2,5,6-dibenzanthracene has been studied, and in general they bind much more than the parent hydrocarbon, especially 2-phenylphenanthrene-3,2′-dialdehyde, which is not carcinogenic. An attempt was made to find out whether this compound is a metabolite of 1,2,5,6-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.
This work was supported in part by a research grant, C-1132, from the National Cancer Institute, National Institutes of Health, Public Health Service, and by a grant from the Wisconsin Section of the American Cancer Society.