Experimental study on the appearance of the dark cell in the chick liver: light and electron microscopic observation.

The presence of the so-called "dark cell" has been reported in the liver, (C I a r a, 1932, T a u c h i et al., 1953) as well as in the kidney, small intestine and in the cancer tissues (T a u c h i, 1961), even in the light microscopic observation. The proper cell is confirmed its presence also on the electron microscopic level, in the liver (T a k a g 1960, 1964, Yasuda et al., 1968) and in the pancreas (I c h i k a w a, 1967), within the range of the parenchymal organs. During the course of the histochemical experiment to demonstrate the site of succinic dehydrogenase, unexpected accumulation of the dark cells was found in the normal chick liver. While in the tissue blocks from the same liver and treated with the regular procedure for the electron microscopy, there are only few dark cells scattered randomly in the tissue. These phenomena awake interest in searching for the conditions to facilitate the appearance of the dark cell in the liver. The present study was undertaken to look for the experimental condition to visualize the dark cell in the chick liver, aiming at the elucidation of reason for the appearance of the dark cell.