The Formation of Blood Vessel After the Administration of the Plasmid Encoding Ang-1 Gene in Fischer Rats

Chronic limb ischemia is a serious clinical problem. Patients who do not qualify for standard treatment may benefit from novel gene therapies.

This study evaluated angiogenesis following intramuscular injections of angiogenic plasmid Ang-1 in Fisher rats.

Twenty rats had plasmids injected intramuscularly in their hind limbs. The study group consisted of 10 animals which received the Ang-1 plasmid, while the control group consisted of 10 rats that received an empty plasmid. All the animals were euthanized after 12 weeks and tissue samples from the hind limb thigh muscles and internal organs were harvested for histological and immunohistochemical examinations. To assess the angiogenesis the number of vessels in the hind limb muscles visualized by the SMA and FVIII markers was counted for each animal in five separate microscopic fields.

There were no pathological lesions or any signs of neoplastic angiogenesis in any of the 20 rats. The number of vessels visualized by the FVIII marker in the study group was two times higher than in the control group (median: 12, range: 7-25 vs. median: 6, range: 2-15; p < 0.0001). The median estimated that the number of vessels visualized by the SMA marker is 63% higher in the study group compared to the control group (median: 6.5, range: 1-12 vs. median: 4, range: 0-10; p = 0.0008).

Intramuscular injections of Ang-1 plasmids induced angiogenesis in the rat hind limb muscles.