title: Elevation of the nasal mucosal surface temperature after warming of the feet occurs via a neural reflex.
abstract: OBJECTIVE
  To evaluate in humans the mechanisms underlying the increase in nasal mucosal temperature following immersion of the feet in warm water (42 degrees C).
  
  
  METHODS
  The nasal mucosal temperature of subjects was measured whilst their feet were immersed in warm water.
  
  
  RESULTS
  The nasal mucosal temperature rose quickly on immersion and dissipated equally fast on removal of the feet from warm water. Intranasal lidocaine raised the mucosal temperature slightly after application, but also blocked the feet warming-induced increase in nasal mucosal temperature, suggesting a neural reflex. Whereas the cutaneous-nasal reflex stimulates a transient parasympathetic response, acetylcholine does not seem to contribute to the more prolonged increase in nasal mucosal temperature following immersion of the feet in warm water. Warming of the feet probably leads to a loss of alpha-sympathetic activity of nasal blood vessels and an increase in nasal mucosal temperature because application of phenoxybenzamine, an alpha-sympathetic blocking agent, to the nasal mucosa increased the nasal mucosal temperature.
  
  
  CONCLUSIONS
  Our data suggest that the increase in nasal mucosal temperature after warming of the feet is mediated by a neural reflex, which is caused by loss of sympathetic activity of the nasal vasculature and a possible additional contribution of a long-acting parasympathetic mediator.
authors.affiliation: Section of Otolaryngology--Head and Neck Surgery, The Pritzker School of Medicine, The University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: Paraya
authors.initials: P
authors.lastname: Assanasen
authors.forename: Fuad M
authors.initials: FM
authors.lastname: Baroody
authors.forename: Lauran
authors.initials: L
authors.lastname: Haney
authors.forename: Marcy
authors.initials: M
authors.lastname: deTineo
authors.forename: Edward
authors.initials: E
authors.lastname: Naureckas
authors.forename: Julian
authors.initials: J
authors.lastname: Solway
authors.forename: Robert M
authors.initials: RM
authors.lastname: Naclerio
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000328:Adult; D000779:Anesthetics, Local / Q000494:pharmacology; D016022:Case-Control Studies; D018680:Cholinergic Antagonists / Q000494:pharmacology; D018592:Cross-Over Studies; D005260:Female; D005528:Foot; D006358:Hot Temperature; D006801:Humans; D007101:Immersion; D009241:Ipratropium / Q000494:pharmacology; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D009297:Nasal Mucosa / Q000098:blood supply / Q000502:physiology*; D010643:Phenoxybenzamine / Q000494:pharmacology; D012018:Reflex / Q000187:drug effects / Q000502:physiology*; D012039:Regional Blood Flow; D012881:Skin Temperature / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000187:drug effects; D014867:Water
chemical_list: D000317:Adrenergic alpha-Antagonists; D000779:Anesthetics, Local; D018680:Cholinergic Antagonists; D014867:Water; D010643:Phenoxybenzamine; D008012:Lidocaine; D009241:Ipratropium