Morphometric analysis of liver in rainbow trout: Quantitatively defining an organ of xenobiotic metabolism

The process of uptake, metabolism and eventual biliary excretion of xenobiotics by the teleost liver affords an opportunity for alteration within at least the following cells: sinusoidal endothelial, perisinoidal fat-storing (vitamin A-containing),¹ hepatocytes and biliary epithelial (of preductules, ductules and intrahepatic ducts). Our understanding of the existence and role(s) in physiologic and pathobiologic phenomena of non-hepatocytic populations of cells in teleost liver has been hampered by the use of immersion fixation procedures obviating resolution and analysis of sinusoidal lining cells and by the subjective nature of light and electron micrographs. The purpose of this study was to quantitatively define the rainbow trout (Salmo gairdneri, Richardson) liver. Computer-assisted morphometry² was conducted on livers of actively spawning 5 year old male and female trout (Wytheville strain).