Appearance of a Carcinoid–like Pattern in Rat Hepatic Tumors Induced by 3′–Methyl‐4–dimethyl ‐aminoazobenzene

Abstract

This study investigated the histological distribution of argyrophilic cells in experimental hepatic neoplasms, the number of these cells, and the proportion of neoplasms with such cells. Seventy 6–week–old male Donryu rats were given a 0.06% 3′–methyl–4–dimethyl–aminoazobenzene (3′–MeDAB) diet for 10 weeks, followed by an ordinary diet for an additional 10 weeks. Of the 70 rats, 50 were used for this investigation; 29 had hepatic tumors, 18 had cholangiofibrosis, and the other three had oval cell proliferation only. Hepatic tissues were stained with Grimelius and Fontana–Masson stains as well as routine hematoxylin–eosin stain. Argyrophilic cells were found in the hepatic neoplasms of 8 rats without argentaffin cells, while cholangiofibrosis was associated with argentaffin cells in almost all cases. Of the 8 rats with argyrophilic cells, three had an abundant population of these cells. The argyrophilic cells were found in areas of the neoplasms with a glandular, trabecular, tubular, or poorly differentiated pattern. Electron microscopy revealed that the neoplastic cells with a positive argyro–phil reaction contained small round electron–dense endocrine granules. In addition, in the areas of cholangiofibrosis, two different types of gut endocrine cells were present (G and EC cells). These results suggest that 3′–MeDAB might induce hepatic carcinoid under certain conditions, though we have yet to confirm the development of a pure hepatic carcinoid due to this substance.

Serum and Liver Tissue Metabonomic Study on Fatty Liver in Rats Induced by High‐Fat Diet and Intervention Effects of Traditional Chinese Medicine Qushi Huayu Decoction

“…A portion from each of the right lobes of the liver obtained from each rat was fixed in 10% neutral formalin, embedded in paraffin, and sliced into 5 μ m thick sections. The samples were stained with hematoxylin-eosin (H&E) and Sirius red, respectively [ 24 ].…”

Liver stem cells: when the going gets tough they get going

“…For instance, they can differentiate into intestinal absorptive cells (Tatematsu et al 1985), goblet cells (Tatematsu et al 1985;Golding et al 1995), and endocrine and Paneth cells (Karaki et al 1991;Elmore & Sirica 1993). In humans, endocrine differentiation can occur in normal bile ducts (Kurumaya et al 1989), in ductular hyperplasia accompanying regeneration after submassive necrosis (Roskams et al 1991), and in cholangiocarcinomas (Roskams et al 1993b).…”

Pluripotential liver stem cells: facultative stem cells located in the biliary tree

“…In rodents, oval cells are certainly not restricted to differentiation along the biliary and hepatocyte cell lineages, and additionally appear to have the lineage potential of uncommitted gastrointestinal stem cells in being able to differentiate into intestinal absorptive cells (Tatematsu et al 1985), goblet cells (Tatematsu et al 1985, Golding et al 1995, and both endocrine and Paneth cells (Karaki et al 1991, Elmore & Sirica 1993. In man endocrine differentiation also occurs in normal bile ducts (Kurumaya et al 1989), during ductular hyperplasia accompanying both regenerating liver after submassive necrosis (Roskams et al 1991) and in primary liver tumours (Roskams et al 1993a, Roskams et al 1993b.…”