title: In vivo single human sweat gland activity monitoring using coherent anti-Stokes Raman scattering and two-photon excited autofluorescence microscopy.
abstract: BACKGROUND
  Eccrine sweat secretion is of central importance for control of body temperature. Although the incidence of sweat gland dysfunction might appear of minor importance, it can be a real concern for people with either hypohidrosis or hyperhidrosis. However, sweat gland function remains relatively poorly explored.
  
  
  OBJECTIVE
  To investigate the function of single human sweat glands.
  
  
  METHODS
  We describe a new approach for noninvasive imaging of single sweat gland activity in human palms in vivo up to a depth of 100 μm, based on nonlinear two-photon excited autofluorescence (TPEF) and coherent anti-Stokes Raman scattering (CARS).
  
  
  RESULTS
  These techniques appear to be useful compared with approaches already described for imaging single sweat gland activity, as they allow better three-dimensional spatial resolution of sweat pore inner morphology and real-time monitoring of individual sweat events. By filling the sweat pore with oil and tuning the CARS contrast at 2845 cm(-1) , we imaged the ejection of sweat droplets from a single sweat gland when oil is pushed out by sweat flow. On average, sweat events lasted for about 30 s every 3 min under the conditions studied. On the other hand, about 20% of sweat glands were found inactive. TPEF and CARS were also used to study, at the single pore level, the antiperspirant action of aluminium chlorohydrate (ACH) and to reveal, for the first time in vivo, the formation of a plug at the pore entrance, in agreement with reported ACH antiperspirant mechanisms.
  
  
  CONCLUSIONS
  Although data were acquired on human palms, these techniques show great promise for a better understanding of sweat secretion physiology and should be helpful to improve the efficacy of antiperspirant formulations.
authors.affiliation: Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel, UMR 7249, Domaine Universitaire de Saint Jérôme, F-13397, Marseille CEDEX 20, France.
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.affiliation: Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel, UMR 7249, Domaine Universitaire de Saint Jérôme, F-13397, Marseille CEDEX 20, France.
authors.forename: P
authors.initials: P
authors.lastname: Gasecka
authors.affiliation: L'Oréal Recherche Avancée, 1 Avenue Eugène Schueller, 93600, Aulnay-sous-Bois, France.
authors.forename: F
authors.initials: F
authors.lastname: Formanek
authors.affiliation: L'Oréal Recherche Avancée, 1 Avenue Eugène Schueller, 93600, Aulnay-sous-Bois, France.
authors.forename: J-B
authors.initials: JB
authors.lastname: Galey
authors.affiliation: Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel, UMR 7249, Domaine Universitaire de Saint Jérôme, F-13397, Marseille CEDEX 20, France.
authors.forename: H
authors.initials: H
authors.lastname: Rigneault
mesh_terms: D000328:Adult; D000536:Aluminum Hydroxide / Q000494:pharmacology; D051520:Antiperspirants / Q000494:pharmacology; D002712:Chlorides / Q000494:pharmacology; D005260:Female; D006225:Hand; D006801:Humans; D021621:Imaging, Three-Dimensional; D008856:Microscopy, Fluorescence / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods; D013542:Sweat / Q000378:metabolism; D013545:Sweat Glands / Q000502:physiology*; D013546:Sweating / Q000502:physiology
chemical_list: D051520:Antiperspirants; D002712:Chlorides; C534453:aluminum sesquichlorohydrate; D000536:Aluminum Hydroxide