Pancreatic hepatocytes associated with chronic 2,6-dichloro-p-phenylenediamine administration in Fischer 344 rats.

Pancreatic tissue (original and recut sections) from Fischer 344 rats fed 2,6-dichloro-p-phenylenediamine in a chronic (2-year) carcinogenesis bioassay was evaluated for presence of pancreatic hepatocytes (PH) by light microscopy. PH were found in dose groups as follows: males--0 ppm (controls)--0/50 (0%), 1,000 ppm--4/50 (8%), 2,000 ppm--9/50 (18%); females--0 ppm (controls)--1/50 (2%), 2,000 ppm-15/50 (30%), 6,000 ppm--15/49 (31%). This represented a significant dose-related increased incidence of PH in 2,000-ppm males, and 2,000- and 6,000-ppm females. A statistically significant increase (p less than 0.01) in pancreatic acinar atrophy and fibrosis was also seen in treated female rats, but the relationship of these lesions to the PH is unclear.