Abstract
AIM: To verify the expressing efficiency and angiogenesis effect after administration of expression vector encoding for vascular endothelial growth factor D in normal and ischemic rat liver. METHODS: Ten female S-D rats were administrated with liver tissue dot injection of naked PCHO/hVEGF-D, 50 microg/dot, three dots for each. The same amount of physiological saline was used as control in the neighboring lobe. Fourteen S-D rats, using inflow occlusion of left lateral lobe, were divided into two groups, seven rats in each group. One was ischemic plasmid group, which received naked plasmid PCHO/hVEGF-D injection of 150 microg. The other received the equal amount of natural saline injection and designed as control. The expressions of hVEGF-D in mRNA and protein levels were identified by in situ hybridization and immunohistochemistry, respectively. Endothelial cells were labeled by the factor VIII immunohistochemistrically. The average number of peri-sinusoidal capillaries of each group was calculated and compared statistically 8 days after injection. RESULTS: A large amount of hVEGF-D in mRNA level was found in both normal and ischemic plasmid groups and but none in their corresponding control groups. The protein of hVEGF was also highly expressed in both normal and ischemic plasmid groups than in the controls. The mean number of capillaries under microscopy (X200) of the plasmid group and control was 10.2+/-2.78 vs 7.1+/-2.02 (P<0.05), and those of ischemic plasmid group and ischemic control were 7.43+/-1.72 vs 4.71+/-1.11 with statistical difference (P<0.05). CONCLUSION: The naked PCHO/hVEGF-D dot injection to normal, ischemic rat liver can produce comparatively high expression of hVEGF in both protein and mRNA levels, and prominently increase the number of new capillaries around hepatic sinuses. Therefore, it could be another ideal choice for the treatment of ischemic liver diseases.