Liver histopathology and accumulation of melano-macrophage centres in Hoplias malabaricus after long-term food deprivation and re-feeding

In the Neotropical traira Hoplias malabaricus, hepatocyte surface area declined after 30 days of fasting due to reserve utilization. Changes in normal organization of liver were not confirmed until 180 days of fasting. Severe histopathological changes occurred after 240 days. Pigment accumulation in the hepatocytes and increase in number and size (surface area) of melano-macrophage centres (MMC) were also verified during long-term food deprivation. The melano-macrophages were rich in ferric compounds, probably haemosiderin. This suggests that the activity of hepatic macrophages is related to the intense erythrocyte degradation that occurred in traira following long-term food deprivation. After re-feeding for 30 days, the liver presented a partial restoration, but the large MMC remained. When compared to the respective starved group, the hepatocytes of re-fed fish increased in size, revealing recovering cell activity and storage of some energy reserves. (C) 2007 The Authors.