The processing and utilization of hepatocyte growth factor/scatter factor following partial hepatectomy in the rat

Hepatocyte growth factor/scatter factor (HGF/SF) is a pluripotent growth fa ctor capable of acting as a motogen, a morphogen, and a mitogen. Originally , HGF/SF was found as a blood-borne mitogen for hepatocytes and has since b een determined to be very important in liver repair. Previous studies have established that HGF/SF must be proteolytically cleaved to elicit its effec ts. After liver injury by toxins such as carbon tetrachloride or after surg ical resection, partial hepatectomy (PHX), HGF/SF concentrations increase i n the blood. The aims of this study were to examine (1) which form of HGF/S F is present in the normal liver, (2) which form is present in the regenera ting liver after PHX, and (3) if the HGF/SF used after PHX is derived from existing liver reservoirs. Both single-chain HGF/SF and active two-chain HG F/SF are present in normal liver, with the former being the dominant form. After PHX, the liver can be described as having two phases with regard to t he use of endogenous HGF/SF. The first phase from 0 to 3 hours is the consu mptive phase and is characterized by a decrease in both single-chain HGF/SF and active two-chain HGF/SF. The second phase is the productive phase. It is characterized by a pronounced reappearance of both single-chain HGF/SF a s well as two-chain HGF/SF. The activation index shows a 5-fold increase ov er sham operations during the productive phase. The use of radiolabeled HGF /SF showed that during the first 3 hours, HGF/SF is used in part from hepat ic stores. Furthermore, during the first 3 hours after PHX, only active two -chain HGF/SF is seen in the plasma.