The pattern of glycogen distribution in the liver

The behaviour of glycogen in the rat liver under conditions of fasting, refeeding, and cortisone administration has been investigated in a combined chemical and histochemical study. In contrast to the observations of others the distribution of glycogen in the liver was found to be reasonably uniform. Histochemically, the periodic acid‐Schiff reaction was considered to be the method of choice for the assessment of glycogen, particularly at low levels. In sections from frozen dried liver, however, reasonably good results could also be obtained with Best's carmine stain, although this stain was not very sensitive at the lower, and was thought to be too dense for accurate visual assessment at the higher levels of glycogen. As far as the intralobular distribution of glycogen was concerned, no fixed zones of “glycogen deposition” and “glycogen withdrawal” were found, since the intralobular gradient could be altered by varying the experimental conditions. This observation led to the postulate of a “glycogenic wave,” which not only helps to explain some of the contradictory findings in the literature on the localization of glycogen in the liver, but which can also be reconciled with the traditional concept of the liver lobule. The “heterogeneity of the cell population” in the liver lobule was considered to be a function of time rather than of fixed anatomical features.