Preventive and therapeutic effects in rats of hepatocyte growth factor infusion on liver fibrosis/cirrhosis.

Liver fibrosis/cirrhosis is characterized by hyper-accumulation of fibrous tissue components and is commonly observed in later or terminal states of chronic hepatic diseases. In ongoing work, we found that the administration of human recombinant hepatocyte growth factor (hrHGF) suppressed the onset of liver fibrosis/cirrhosis in several distinct models and accelerated the recovery from liver fibrosis/cirrhosis in rats. Repeated administration of porcine serum for 10 weeks to rats induced liver fibrosis without any accompanying hepatocellular injuries; in addition, the intravenous (i.v.) administration of hepatocyte growth factor (HGF) to these rats suppressed increases in fibrous components and hydroxyproline contents in the liver, thus preventing the onset of liver fibrosis. Repeated administration of dimethylnitrosamine (DMN) for four weeks induced liver cirrhosis, as characterized by the hyper-accumulation of fibrous components, infiltration of mononuclear leukocytes, and hepatic dysfunction. When HGF was injected daily for four weeks along with DMN-treatment, the onset of DMN-induced hepatic fibrosis/cirrhosis was suppressed; the numbers of infiltrating mononuclear cells, fibrous tissue components, and hydroxyproline content in the liver were decreased. When HGF was injected for two weeks following four weeks of DMN-treatment, HGF accelerated the recovery from liver cirrhosis and prevented death due to hepatic dysfunction. Likewise, HGF-injection suppressed the onset of liver fibrosis, when liver fibrosis had been induced by long-term treatment with carbon tetrachloride (CCl4). Thus, the administration of HGF holds great promise for treating subjects with liver fibrosis/cirrhosis as a result of chronic hepatic injury.