Objective: To investigate the effect of plasmid pUDKH carrying human hepatocyte growth factor (HGF) gene on rat acute limb ischemia and to find the lowest effective dosage.
Methods: Ligation of femoral artery of one hindlimb in Wistar rats was performed. The rats were randomly divided into 5 groups of 10 rats: pUDKH 50 microg, 100 microg, 200 microg, and 400 microg groups and a vacant vector pUDK group (control group). The plasmids were injected once directly into the ischemic limb muscle (5 sites around ligation position) immediately after ligation. At day 10, the muscles were removed and stained with H.E. to assess histologically the blood vessel formation. HGF expression was detected in the muscle tissue of another 12 rats on days 3, 5, 10, 14, 21, 30 after injection of pUDKH or pUDK, 200 microg each per animal.
Results: HGF expression was detected clearly in muscle tissue on days 3, 5, 10, 14 in pUDKH groups. In HGF-transfected animals (except for 50 microg group) neoformation of blood vessels in muscles and soft tissues was found, while it was not seen in controls. By semi-quantitation of the degree of vessel formation, significant differences between pUDKH groups (0.96 +/- 0.07, 1.97 +/- 0.91, 2.26 +/- 1.00 for 100 microg, 200 microg, 400 microg, respectively) and the control group (0.27 +/- 0.04) (P < 0.05) were noted. In addition, injection of pUDKH could alleviate the severity of degeneration of muscular tissue due to ischemia.
Conclusion: Human HGF gene therapy is effective in treating rat acute limb ischemia with the lowest effective dose of 100 microg.