Take from the Journal of Exercise Physiology Online:
"This is a follow-up commentary to a recent paper in this journal on Marc ProTM electrical device stimulation (MPDS) showing Delayed Onset of Muscle Soreness (DOMS) recovery. We hypothesized that MPDS increases arteriolar diameters, a mechanism involved in the recovery process, and that repeated MPDS would elicit angiogenesis, a mechanism involved in conditioning and improved performance. First, arteriolar diameters were measured in the cremaster muscle of 57 male, anesthetized rats using intravital microscopy before and after MPDS or sham stimulation (SS) at 1 or 2 Hz for periods of 30-60 min. In a separate cohort, the role of nitric oxide (NO) in the response to MPDS was assessed by blocking NO synthase
using topical L-nitro-arginine-methyl ester (L-NAME) at 10-5 M (Molar). Maximal arteriolar responses to stimulation were compared to pre-stimulation diameters. MPDS both at 1 and 2 Hz resulted in significant arteriolar vasodilation (P<0.05). The arterioles in SS animals demonstrated no changes in diameter. Similarly, microvascular diameters did not change with MPDS following blockade of NO production. Secondly, the effects of repeated MPDS on blood flow and angiogenesis in the rat hind limb were studied. Animals were MPDS-conditioned ("Conditioned") or sham-stimulated ("Sham") (n = 5/group) daily for 3 wk. The contralateral limb in both groups served as the control. Each animal was injected with bromodeoxyuridine (BrDU). After 3 wk, rats were anesthetized and iliac artery blood flow was measured bilaterally before, during, and after acute MPDS. Conditioned limbs elicited a 247% increase in limb blood flow above resting conditions compared to a 200% increase in the control legs receiving only a single application. Sham animals did not demonstrate between-leg differences in flow. Hind limb musculature staining for BrDU revealed angiogenesis in Conditioned vs. Sham groups. Flow changes accompanying MPDS corroborated earlier microvascular findings demonstrating a significant striated muscle arteriolar dilation with MPDS. We are confident that these properties of MPD variant technology derived from animal studies showing NO-dependent enhanced microcirculation, muscle loading and angiogenesis, improved muscle performance, and recovery from concentric and eccentric exercise induced muscle fatigue will be confirmed in larger studies."