Effect of sulfonated azo dyes on mouse tumors.

The possible relationship between deficient reticulo-endothelial function and neoplasia has been investigated by several workers (7). Some in vestigators utilized the hypothetical relationship between reticulo-endothelial function and tumors for therapeutic approaches; in other words, at tempts were made to combat malignant tumors by methods which were expected to increase reticuloendothelial activity. These mostly unsuccessful endeavors will not be reviewed here; however, it may be remarked that in most instances complex biologic stimuli were employed for the purpose of enhancing reticulo-endothelial function. It was thought possible that stimulation of reticulo-endot helial tissues by means of chemical compounds, defined as to their structure and amenable to ex act dosage, might represent a more promising approach (4). The present study was prompted by a report made by Cestari (1) in 1940 regarding the effect of sulfonated Sudan IV (scarlet red) on the Kuptfor cells in the rabbit. According to this author, pro longed intravenous injections of Sudan IV were followed by deposition of the dye in the KupfiVr cells; from there it gradually passed into parenchymal cells, causing degenerative changes and proliferation of connective tissue, and this ulti mately led to a condition resembling cirrhosis. When the author, however, used a sulfonated de rivative of Sudan IV, which was more readily water-soluble, this dye was taken up by the Kupffer cells, caused them to proliferate in re sponse to the storage, and was eliminated without any apparent damage to the liver. On the basis of this report, it was thought worth-while to investigate the effect of sulfonated azo dyes on reticulo-endothelial activity and tu mors of mice. A number of such compounds were made available by the National Aniline Division, Allied Chemical and Dye Corporation.1 The com-