Improvement in Angiogenesis and Restoration of Blood Flow in Diabetic Mice by Sanguinate TM

To improve angiogenesis and restoration of blood flow in diabetic mice subjected to hind limb ischemia, here we test the hypothesis that Sanguinate (PEG-COHb), which resides in the plasma and increases the efficiency of oxygen transfer, promotes these improvements. Wild type C57BL/6 mice at age 6 weeks were rendered diabetic with streptozotocin (stz) and at age 12 weeks were subjected to femoral artery (FA) ligation followed by administration of PEG-COHb (20 ml/kg/day) via intraperitoneal (IP) injection daily for 4 weeks. Vehicle treated diabetic mice received IP injection with equal volumes of 1xPBS daily. Diabetic mice treated with PEG-COHb displayed significantly improved blood flow ratios (ischemia/sham) by laser Doppler analysis on day 28 after FA ligation compared to vehicle treated group (63.36 ± 5.83 vs 44.39 ± 4.13 BFR (%), n≥9, p=0.019). Immunohistochemistry with anti-CD31 IgG demonstrated significantly increased microvessel density in the muscle tissue of diabetic mice treated with SanguinateTM on day 28 after FA ligation compared to vehicle treated group (663.86 ± 57.78 vs 461.44 ± 36.19 capillaries/mm2, p<0.0001). Taken together, these data reveal significant therapeutic effects of SanguinateTM in diabetic limb ischemia in a murine model and may provide the basis for the use of this agent as complementary vascular-salvaging therapy in long-standing diabetes.