Electrical pharyngeal stimulation increases substance P level in saliva

• Published in: Neurogastroenterology and motility Vol. 28; no. 6; pp. 855 - 860
• Main Authors: Suntrup‐Krueger, S., Bittner, S., Recker, S., Meuth, S. G., Warnecke, T., Suttrup, I., Marian, T., Dziewas, R.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.06.2016
• Subjects: Adult; Cross-Over Studies; Electric Stimulation - methods; electrical pharyngeal stimulation; Female; Humans; Male; neurogastroenterology; neurogenic dysphagia; Pharynx - metabolism; Pilot Projects; Saliva - metabolism; substance P; Substance P - blood; Substance P - metabolism; swallowing; Young Adult; neurogastroenterology; swallowing; neurogenic dysphagia; substance P; electrical pharyngeal stimulation
• ISSN: 1350-1925; 1365-2982
• DOI: 10.1111/nmo.12783

Background Substance P (SP) is a neuropeptide known to enhance the swallow response. It likely acts as a neurotransmitter in the pharyngeal mucosa in response to local stimuli. It has been proposed that dysphagia after stroke may be related to reduced levels of SP, which therefore constitutes a therapeutic target. In the present pilot study, we evaluated whether electrical pharyngeal stimulation (EPS), a neuromodulation device to enhance cortical reorganization for the restoration of swallowing function after brain injury, is able to increase SP in saliva or serum. Methods In a randomized crossover study design, 20 healthy volunteers were treated with 10 min of real (0.2‐ms pulses, 5 Hz, 280 V, stimulation intensity (mA) individually adjusted to tolerance level) or sham EPS on two separate sessions. Stimulation was delivered via a pair of bipolar ring electrodes mounted on an intraluminal catheter positioned in the pharynx. Blood and saliva samples were taken prior to, during, and up to 1 h after EPS and analyzed for their SP concentration by ELISA. Key Results Following real EPS but not sham stimulation, SP levels in saliva increased immediately and significantly about 28% (p < 0.01) compared to baseline. Serum levels remained unchanged. Conclusions & Inferences Electrical pharyngeal stimulation is able to induce pharyngeal SP release in healthy subjects. Substance P (SP) constitutes an interesting therapeutic target for dysphagia as it is a neuropeptide in pharyngeal sensory afferents known to enhance the swallow response. In our randomized controlled study on healthy volunteers, saliva SP concentration increased after 10 min of electrical pharyngeal stimulation (EPS). We conclude that EPS is able to induce pharyngeal SP release.