Hepatocyte growth factor suppresses ischemic cerebral edema in rats with microsphere embolism

The present study was aimed at determining whether human recombinant hepatocyte growth factor (HGF) ameliorates cerebral edema induced by microsphere embolism (ME). Rats were injected with 700 microspheres (48 microm in diameter). Continuous administration of HGF at 13 microg/3 days/animal into the right ventricle was started from 10 min after embolism to the end of the experiment by using an osmotic pump. On day 3 after the ME, the rats were anesthetized, and their brains were perfused with an isotonic mannitol solution to eliminate constituents in the vascular and extracellular spaces. Thereafter, tissue water and cation contents were determined. A significant increase in tissue water content of the right hemisphere by ME was seen. This ME-induced increase in water content was associated with increases in tissue sodium and calcium ion contents and decreases in tissue potassium and magnesium ion contents of the right hemisphere. The treatment of the animal with HGF suppressed the increases in water and sodium and calcium ion contents, but not the decreases in potassium and magnesium ion contents. These results suggest that HGF suppresses the formation of ischemic cerebral edema provoked intracellularly in rats with ME.