title: The influence of chemical gustatory stimuli and oral anaesthesia on healthy human pharyngeal swallowing.
abstract: This study explored the effects of taste and oral anaesthesia on human sequential swallowing. Subjects were healthy adults (n = 42, mean age 28 years, 21 females), investigated by means of a water swallow test. Taste stimuli comprised quinine, glucose, citrus and saline solutions compared with neutral water. Oral anaesthesia comprised topical lidocaine at doses of 10, 20 and 40 mg and compared with placebo. Data were collected on swallowing speed (volume per second), inter-swallow interval and swallowing capacity (volume per swallow). Compared with water, glucose, citrus and saline reduced swallowing speed (10.94 +/- 0.89 versus 9.56 +/- 0.79, 9.33 +/- 1.19, 9.37 +/- 0.92 ml/s respectively, P < 0.05). Inter-swallow interval was increased only by quinine and saline (1.47 +/- 1.11 versus 2.13 +/- 0.34 and 1.92 +/- 0.31 s, P < 0.04). Swallowing capacity was only marginally increased by quinine (P = 0.0759). Compared with the placebo, only 40 mg of lidocaine altered swallowing, immediately reducing the swallowing speed (7.89 +/- 2.34 versus 10.11 +/- 3.26 ml/s, P < 0.05) and increasing inter-swallow interval (1.67 +/- 0.38 versus 1.45 +/- 0.29 s, P < 0.01) without affecting capacity. By 15 min all measures except sensory thresholds had returned to baseline values. Thus, swallowing function is highly influenced by chemosensory input, providing insight into how oral sensation regulates pharyngeal swallowing.
authors.affiliation: Manchester Medical School, Stopford Building, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
authors.forename: Carolyn
authors.initials: C
authors.lastname: Chee
authors.forename: Shoaib
authors.initials: S
authors.lastname: Arshad
authors.forename: Salil
authors.initials: S
authors.lastname: Singh
authors.forename: Satish
authors.initials: S
authors.lastname: Mistry
authors.forename: Shaheen
authors.initials: S
authors.lastname: Hamdy
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000772:Anesthesia, Local; D002957:Citrus; D003679:Deglutition / Q000187:drug effects / Q000502:physiology*; D005260:Female; D005947:Glucose; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D010614:Pharynx / Q000502:physiology*; D011803:Quinine; D013649:Taste / Q000502:physiology*
chemical_list: D008012:Lidocaine; D011803:Quinine; D005947:Glucose