Kupffer cell hyperplasia in rats intoxicated by carbon tetrachloride as demonstrated by scanning electron microscopy.

Kupffer cells were observed and counted by scanning electron microscopy (SEM) to demonstrate rat Kupffer cell hyperplasia after carbon tetrachloride (CCl4) intoxication. Kupffer cell number per 0.1 mm2 of the periportal zone (65.0 +/- 4.2) was 1.6 times of that of the central zone (41.8 +/- 4.5) in normal rats (P less than 0.001). Kupffer cell number per mm3 of normal rat liver was about 16,500. Kupffer cells did not increase until 24 hours after CCl4 administration. However, at 48 hours, when hepatocytes showed necrosis in the central zone. Kupffer cells proliferated 1.7 times of control rats in the periportal zone and 5.2 times in the central zone. The present SEM study also disclosed surface changes of Kupffer cells after CCl4 administration. At 6 to 24 hours, ruffles, blebs and microvillous projections reduced in many Kupffer cells. At 48 hours, Kupffer cells became to have numerous long filopodia and microvillous projections and the cells were frequently connected with each other by filopodia. Several Kupffer cells and lymphocytes composed mesenchymal conglomerates in some places of the central necrotic zone. In conclusion, the present SEM study demonstrated predominant perilobular population of Kupffer cells in normal rats and Kupffer cell hyperplasia after CCl4 intoxication.