The Induction of Tumours of the Subcutaneous Tissues, Liver and Intestine in the Mouse by Certain Dyestuffs and their Intermediates

THE purpose of the experiments about to be described was to test a number of amines and azo-dyes for carcinogenic activity in the mouse, a species which has been comparatively little used for the investigation of this type of compound. The chemicals chosen were 2 dyes (auramine and magenta), the manufacture of which constitutes an industrial hazard according to Case and Pearson (1954); 6 dyes formerly or at present in use as food colorants (carmoisine, rhodamine B, sunset yellow, ponceau 2R, xylylazo-2-naphthol and o-tolylazo-2-naphthol); 3 dyestuffs intermediates (benzidine, 1-naphthylamine and 2-naphthylamine); and 2 ortho hydroxy amines related to known metabolites of aromatic amines (3: 3'-dihydroxybenzidine hydrochloride and 0-methyl-2-amino-1-naphthol hydrochloride). The tumours induced by the chemioals were of three types: subcutaneous sarcomas, hepatomas and intestinal polyps and carcinomas. Spontaneous intestinal tumours in the mouse have been described occasionally (Table I). Murray (1905, 1908) found 2 adenocarcinomas in the small intestin

A Further Study of Bladder Implantation in the Mouse as a means of Detecting Carcinogenic Activity: Use of Crushed Paraffin Wax or Stearic Acid as the Vehicle

IN previous investigations where bladder implantation in the mouse was used to detect carcinogenic activity (Bonser, Bradshaw, Clayson and Jull, 1956; Allen, Boyland, Dukes, Horning and Watson, 1957; Clayson, Jull and Bonser, 1958) the pellets were made either from molten paraffin wax or compressed cholesterol. Wax had the disadvantage that the chemicals under test were heated to 70 to 850 C. for several minutes and may thus have undergone decomposition before their introduction into the bladder. Cholesterol, when implanted bv itself. induced more tumours than paraffin wax, which impeded the interpretation of the results. This paper describes the use, in Leeds, of crushed paraffin wax as the vehicle in an attempt to combine the low incidence of tumours caused by melted paraffin wax with the lack of heating needed to make pellets by compression. In London, stearic acid was chosen as the vehicle because it could be compressed into pellets and because as a pure compound it overcame difficulties occasioned by the variability in composition of paraffin wax. The study of potent carcinogenic polycyclic hydrocarbons had hitherto been