Comparative carcinogenicity of two structurally similar phenylenediamine dyes (HC blue no. 1 and HC blue no. 2) in F344/N rats and B6C3F1 mice.

Abstract

Toxicology and carcinogenesis studies of 2 structurally-related p-phenylenediamines, HC Blue No. 1, and HC Blue No. 2 were conducted by administering each chemical in feed for 103 weeks to both sexes of Fischer 344/N rats and B6C3F1 (C57BL/6N x C3H/HEN) mice. Diets containing 0, 1500, or 3000 ppm HC Blue 1 were fed to male and female rats and male mice; female mice received diets with 0, 3000, or 6000 ppm. Diets containing 0, 5000, or 10,000 ppm HC Blue 2 were fed to male rats and mice and the females received diets containing 0, 10,000 or 20,000 ppm. These concentrations were compatible with long-term growth and survival. The results demonstrated substantial differences in the neoplastic and non-neoplastic lesions caused by these structural analogs. HC Blue 2 caused histocytosis in lungs and hyperostosis of the skull in rats, and splenic hematopoiesis, fibrous osteodystrophy, and hyperostosis of the skull in mice. These non-neoplastic lesions were not observed in rats or mice treated with HC Blue 1. Contrasting, in male and female mice, HC Blue 1 produced dose-related increases in the incidences of both adenomas and carcinomas of the liver. HC Blue 1 produced a marginally positive trend in hepatocellular nodules and carcinomas in male rats and dose-related increases in hyperplasias and neoplasms of the lungs in female rats. In contrast, there was no evidence of carcinogenicity for HC Blue 2 in either sex of rats or mice, despite the fact that it was administered 3-5 times the dose of the HC Blue 1. Since these 2 nitroaromatic compounds differ only in the methyl vs. 2-hydroxyethyl substituent on the secondary amine of ring carbon 4, the great discordance in their carcinogenicity is most probably due to side group-directed alteration in their metabolic profiles.

• Authors: F W Kari, J H Mennear, D Farnell, R B Thompson, J E Huff
• Journal: Toxicology (Toxicology) Vol. 56 Issue 2 Pg. 155-65 (Jun 01 1989) ISSN: 0300-483X [Print] Ireland
• PMID: 2734800 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Carcinogens
• Phenylenediamines
• N-methylamino-2-nitro-4-N',N'-bis(2-hydroxyethyl)aminobenzene
• HC Blue No. 2

Topics

• Animals
• Carcinogens
• Female
• Male
• Mice
• Mice, Inbred C3H
• Mice, Inbred C57BL
• Neoplasms, Experimental (chemically induced)
• Phenylenediamines (administration & dosage, toxicity)
• Rats
• Rats, Inbred F344
• Time Factors