Transcutaneous neuromuscular electrical stimulation effect on the degree of microvascular perfusion in autonomically denervated rat skeletal muscle

Objective: To determine the effect of transcutaneous neuromuscular electrical stimulation (TNMES) on the degree of microvascular perfusion in autonomically denervated skeletal muscle. Design: A completely randomized experimental design was used to compare the effects of TNMES on the degree of microvascular perfusion in the tibialis anterior (TA) and extensor digitorum longus (EDL) muscles from autonomically denervated rats (Ch-TES) to the degree of microvascular perfusion in the same muscles of untreated controls, rats receiving only TNMES (TES), and rats receiving only autonomic denervation (shams). Interventions: All electrical stimulation treatments were delivered via carbon silicone surface electrodes, and evoked sustained tetanic contraction of the TA and EDL muscles. Autonomic denervation was achieved by the application of chlorisondamine. Main Outcome Measures: The degree of microvascular perfusion was determined for the deep (DTA) and superficial (STA) regions of the TA muscle and the EDL muscle by calculating their perfused microvessel/muscle fiber (PV/F) ratio. Results: The PV/F ratio in the DTA from Ch-TES animals was greater (p ≤ .05) than that in the same muscle from control and sham animals. The PV/F ratios in the STA and EDL from Ch-TES animals were not significantly (p > .05) different from the PV/F ratio in the respective muscles of shams. Conclusions: The response of the microvasculature in autonomically denervated skeletal muscle to TNMES that evokes muscle contraction is variable, and (2) mechanisms other than autonomic regulation may be involved in this hyperemic response.