EXPERIMENTAL STUDIES ON THE STEM-CELL CONCEPT OF LIVER-REGENERATION -I

There are increasing references for the existence of a hepatic stem or progenitor cell system as well as its participation in the physiologi cal as well as reparative regeneration of the liver and in carcinogene sis. For the physiological regeneration the existence of a dynamic ''c ell-renewal'' system finds increasing consideration and in the ''strea ming liver concept'' (ZAJICEK et al. 1985) its functional expression. This concept is still under discussion. The present paper tries to che ck this animal-experimentally (Wistar rats) under use of two different thymidine analogues (3H-thymidine and Bromodeoxyuridine). In differen t time intervals after labelling (1 h, 14, 30, 60, 90, 120 d) a shift of the labelling bias or a migration of the hepatocytes in the liver a cinus (RAPAPORT) in portovenous direction could be shown. The average migration speed is 0.575 mu m or 0.0315 cell positions per day, the ce ll production rate is one in 31.5 days. The present paper results supp ort the inclusion of a stem or progenitor cell system into the physiol ogical regeneration of the liver and allow the classification into the ''streaming liver concept'' (ZAJICEK et al. 1985).