Regeneration capacity of the liver

The liver has a remarkable capacity to regenerate after injury and to adjust its size to match its host. Within a week after partial hepatectomy, which, in typical experimental settings entails surgical removal of two-thirds of the liver, hepatic mass is back essentially to what it was prior to surgery. Some additional interesting observations include: In the few cases where baboon livers have been transplanted into people, they quickly grow to the size of a human liver. When the liver from a large dog is transplanted into a small dog, it loses mass until it reaches the size appropriate for a small dog. Hepatocytes or fragments of liver transplanted in extrahepatic locations remain quiescent but begin to proliferate after partial hepatectomy of the host. These types of observations have prompted considerable research into the mechanisms responsible for hepatic regeneration, because understanding the processes involved will likely assist in treatment of a variety of serious liver diseases and may have important implications for certain types of gene therapy. A majority of this research has been conducted using rats and utilized the model of partial hepatectomy, but a substantial body of confirmatory evidence has accumulated from human subjects.