Effect of Magnetic Stimulation in Spinal Cord on Limb Angiogenesis and Implication: A Pilot Study

OBJECTIVE: To investigate the effect of repetitive magnetic stimulation (rMS) of the spinal cord on limb angiogenesis in healthy rats and explore its implication for the treatment of lymphedema. METHOD: Twelve adult male Sprague-Dawley rats were divided into four groups as follows: sham rMS followed by tissue harvest 5 minutes later (group 1, n=2), 1 Hz rMS and tissue harvest 5 minutes later (group 2, n=3), 20 Hz rMS and tissue harvest 5 minutes later (group 3, n=3), 20 Hz rMS and tissue harvest 30 minutes later (group 4, n=4). Animals were treated with 20-minute rMS with 120% of the motor threshold on their left side of upper lumbar spinal cord. Expression of angiogenic factors, that is, Akt, phospho-Akt (pAkt), endothelial nitric oxide synthase (eNOS), phospho-eNOS (p-eNOS) were measured by western blot. Bilateral hindlimb muscles (quadriceps and gastrocnemius) were harvested. RESULTS: Expression of Akt in left quadriceps increased in group 4 compared with group 2 and 3 (3.4 and 5.3-fold each, p=0.026). Expression of eNOS in left plus right quadriceps markedly increased in group 3 and 4 compared with group 1 and 2 (p=0.007). Expressions of eNOS, Akt and p-eNOS, pAkt in gastrocnemius were not comparable between four groups (p>0.05). CONCLUSION: Repetitive magnetic stimulation of the spinal cord may exert an angiogenic effect closely linked to lymphangiogenesis. It has clinical implication for the possible therapy of lymphedema caused by breast, cervical or endometrial cancer operation. Future studies with the specific lymphatic endothelial cell markers are required to confirm the effect of rMS on lymphangiogenesis.