An ultrastructural study on a new type of hepatic perisinusoidal cell in fish.

A new type of perisinusoidal cell containing numerous microfilaments is described for the first time. It is found in abundance in the livers of both marine and freshwater fish. These perisinusoidal cells are situated within the space of Disse and adhere firmly through desmosomes both to sinusoidal endothelial cells and to hepatocytes. The cytoplasmic microfilaments are striking and make these cells readily distinguishable from the perisinusoidal fat-storing cells of Ito. Although the function of these cells is not known, the observations presented here suggest that they may provide a supportive framework within the liver.