Light microscopic and electron microscopic study on morphologic features resulting in the delay of ICG elimination in diabetic and non-diabetic fatty liver.

Disturbances of intravenously administered indocyanin green (ICG) elimination are related to the effective circulating blood volume and the amount of binding protein for transportation in blood plasma through the liver because of the narrowed sinusoidal space due to the enlarged liver cells with fullness of confluent fat droplets in the cytoplasma. However, morphologic changes of the liver resulting in disturbances of ICG elimination could not be actually clarified until the present. Therefore, morphologic changes of the liver resulting in delayed ICG elimination in fatty liver, occurring in diabetes mellitus were investigated in contrast with those in fatty liver in non-diabetic, non-alcoholic diseases of the liver. An electron microscopic study of the liver with delayed ICG elimination revealed thickening and amorphous growth of the sinusoidal wall with obscure pores followed by membraneous formation, narrowness of Disse's space, rarefaction of sinusoidal microvilli and proliferation of collagen fibers, in fatty livers derived from both diabetes mellitus and other diseases. The term "intrasinusoidal block" in fatty liver should be utilized on the basis of these electron microscopic features of the liver.