Estimating anatomical-functional position coordinates in liver tissue.

Abstract

Hepatocyte enzyme activity was demonstrated by examining adult C57BL/6 mouse liver cryostat sections under a succinate dehydrogenase (SDH) histochemical reaction, and quantified by microspectrophotometry and microdensitometry. The hepatocyte SDH activity gradient along the path between the portal veins (PV) and efferent terminal hepatic venules (THV) was analyzed by measuring the concentration of the chromophore precipitated in 10 consecutive hepatic parenchymal domains located along imaginary lines drawn across the entire PV-to-THV distance. The profiles of intensity or of normalized relative optical density obtained on a high number of lines were correlated with distance values along the PV-to-THV pathway, enabling us to establish a general mathematical function relating SDH activity (chromophore concentration) to position values on a scale of 0 to 10 corresponding to the theoretical PV-to-THV distance. The equation can be used to interpolate the SDH activity surrounding any intrahepatic object located between the PV and the THV, thus making it possible to calculate the object's anatomical-functional position coordinates in the liver acinus. To demonstrate how this method is used, we have calibrated the intrahepatic position of hemopoietic foci induced in the liver tissue of adult mice treated with phenylhydrazine (PHZ), and show that these foci are located on coordinate 3.31 (maximum range 1.25-4.86) of the sinusoidal domain-that is, on the borderline between Rappaport's acinar zones 1 and 2.