Evaluation of hepatocyte growth factor plasmid therapeutic effect by 99mTc-hexakis-2-methyoxy-isobutylisonitrile blood flow scintigraphy in a rat model of hind limb ischemia.

OBJECTIVE: This study was conducted in an attempt to use blood flow scintigraphy with 99mTc-hexakis-2-methyoxy-isobutylisonitrile (99mTc-MIBI) for the evaluation of the angiogenic effect of hepatocyte growth factor (HGF) plasmid in a rat model of hind limb ischemia. MATERIALS AND METHODS: The femoral artery of the left hind limb of each rat was ligated to create a model of hind limb ischemia. Three weeks later, HGF plasmid (1.5 mg/1.1 ml/body) or saline (1.1 ml/body) was administered intramuscularly into three sites of the ischemic hind limb. Two and 4 weeks after the treatment, blood flow through the hind limb was measured by 99mTc-MIBI scintigraphy. In addition, the number of capillary endothelial cells obtained by immunostaining for CD31 was counted. RESULTS: After 99mTc-MIBI scintigraphy in the HGF plasmid-treated group, the blood flow ratio increased significantly from the pretreatment ratio 63.8 to 73.4%, 2 weeks after treatment (P<0.05) and to 97.8%, 4 weeks after treatment (P<0.05). The number of CD31-positive endothelial cells was significantly higher in the HGF plasmid-treated group than in the control group. CONCLUSIONS: The experimental study using a rat model of hind limb ischemia showed usefulness of 99mTc-MIBI scintigraphy to evaluate the angiogenic effect of HGF plasmid treatment.