Hepatic perisinusoidal stellate cell

N. Kawada, The hepatic perisinusoidal stellate cell, Histol. Histopathol. 72 1069-1080 (1997). 

Studies in vitamin A replete animals suggest that most of the retinol is transferred from hepatocytes to the perisinusoidal stellate cells of the liver. Here, it is again esterified by LRAT to form mainly retinyl palmitate (76% to 80%), with smaller amounts of stearate (9% to 12%), oleate (5% to 7%), and linoleate (3% to 4%). The stellate cells contain 90% to 95% of hepatic vitamin A, as cytoplasmic lipid droplets that consist of between 12% to 65% retinyl esters (Batres and Olson, 1987). Studies with [ C]retinyl palmitate show that much of the recently ingested retinol appears more or less immediately in the... 

Quiescent, perisinusoidal hepatic stellate cells (HSC) accumulate retinoids (vitamin A and its metabolites) in large cytoplasmic droplets and store about 80% of body s retinoids. However, these cells also express the muscle protein desmin and become activated to myofibroblasts upon exposure to hepatotoxicants. Activated HSC synthesize extracellular matrix proteins, especially when stimulated by cytokines and growth factors (see Section 28.4.2). 

The stellate cells are also called perisinusoidal or Ito cells. There are approximately 5 to 20 of these cells per 100 hepatocytes. The stellate cells are lipid-filled cells (the primary storage site for vitamin A). They also control the turnover of hepatic connective tissue and extracellular matrix and regulate the contractihty of the sinusoids. When cirrhosis of the liver is present, the stellate cells are stimulated by various signals to increase their synthesis of extracellular matrix material. This, in turn, diffusely infiltrates the hver, eventually interfering with the function of the hepatocytes. 

The hepatic stellate (or Ito) cells are fat-storing cells found in the perisinusoidal spaces between the hepatocytes and sinusoids these cells can later become involved in hepatic fibrosis. When hepatic lipid is increased by greater than 5% by weight, the histological changes are described as steatosis, or fatty changes. 

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