The non parenchymal cells of the liver include populations of cholangiocytes (epithelial cells), sinusoidal endothelial cells, stellate cells, Kupffer cells, and intrahepatic lymphocytes. Combined they make up 40% of the cells in the liver.
The non-parenchymals produce key paracrine factors that influence growth, metabolism, and transport functions in hepatocytes. Non-parenchymals can be primary targets for certain hepatotoxins and mediate physiological response of the liver to endocrine and immune signals.
Adding non-parenchymals to your primary hepatocyte toxicity testing improves the physiological relevance of the results.