The synergic effects of rapamycin and extremely low frequency electromagnetic field on angiogenesis

Angiogenesis the formation of new blood vessels is a dynamic and complex activity which is needed for embryogenesis and other physiological processes. However in many pathological conditions such as solid tumor progression the disease appears to be associated with persistent up-regulated angiogenesis. In this research we used 0.04 T (tesla) electromagnetic field as a synergic treatment with rapamycin on angiogenesis. In this experimental study 70 Ross fertilized eggs were randomly divided into 5 groups as following: 1) control 2) sham-exposed 3) a group treated with rapamycin 4) a group treated with electromagnetic field and 5) a group treated with both rapamycin and electromagnetic field. In day 2 a window was opened on eggs in sterile condition. In day 8 a gelatin sponge was placed on chorioalantoic membrane (CAM) and was soaked with 5 μl rapamycin in group 3 and group5. Groups 4 and group 5 were placed in 400 Gauss magnetic field for 4 hours in day 10. In day 12 CAMs were examined and photographed by research photo-stereomicroscope in all cases. Data were analyzed using ANOVA and Mann-Whitney tests. Comparison between average number and length of vessels in controls and sham-exposed didn’t show any significant differences. In group 3 and 4 a significant decrease was shown in the average number and length compared with controls. Finally comparison between group 3 and group 5 showed a significant decrease in the average number and length of vessels in group 5 which had been treated with both rapamycin and 400 (Gauss) G electromagnetic field. The results of this study showed that 0.04 T magnetic field has an inhibitory effect on angiogenesis in CAM and can enhance the effect of rapamycin as an anti-angiogenesis drug.