title: Glucose transport by acinar cells in rat parotid glands.
abstract: OBJECTIVE
  Salivary glucose is often considered as being from glandular origin. Little information is available, however, on the possible role of glucose transporters in the secretion of the hexose by salivary glands. The major aim of the present study was to investigate the expression and localization of several distinct glucose transporters in acinar cells of rat parotid glands.
  
  
  METHODS
  Quantitative real-time PCR analysis, immunohistochemistry and western blotting techniques were used to assess the presence of SGLT1, GLUT1, GLUT2 and GLUT4 in acinar cells of rat parotid glands.
  
  
  RESULTS
  Quantitative real-time PCR documented the expression of SGLT1 and GLUT1 in parotid tissues, with a much lower level of GLUT4 mRNA and no expression of GLUT2 mRNA. Western blot analysis revealed the presence of SGLT1, GLUT1 and GLUT4 proteins, but not GLUT2 proteins in the parotid extract. Immunohistochemistry confirmed these findings. SGLT1 was specifically located at the baso-lateral membrane, co-localizing with Na(+)/K(+) ATPase. GLUT1 was found both at the baso-lateral and apical level. GLUT4 appeared to be also located at the baso-lateral level. However, too little GLUT4 was present to allow co-localization labeling.
  
  
  CONCLUSIONS
  Based on these findings, a model is proposed for the transport of glucose into the acinar cells and thereafter into the acinar lumen.
authors.affiliation: Laboratory of Experimental Hormonology, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Cedric
authors.initials: C
authors.lastname: Jurysta
authors.forename: Charles
authors.initials: C
authors.lastname: Nicaise
authors.forename: Sibel
authors.initials: S
authors.lastname: Cetik
authors.forename: Karim
authors.initials: K
authors.lastname: Louchami
authors.forename: Willy J
authors.initials: WJ
authors.lastname: Malaisse
authors.forename: Abdullah
authors.initials: A
authors.lastname: Sener
mesh_terms: D061354:Acinar Cells / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D005947:Glucose / Q000378:metabolism*; D051246:Glucose Transport Proteins, Facilitative / Q000235:genetics / Q000378:metabolism*; D051272:Glucose Transporter Type 1 / Q000235:genetics / Q000378:metabolism; D051273:Glucose Transporter Type 2 / Q000235:genetics / Q000378:metabolism; D007150:Immunohistochemistry; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D010179:Pancreas / Q000166:cytology / Q000378:metabolism; D010306:Parotid Gland / Q000166:cytology / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051269:Sodium-Glucose Transporter 1 / Q000235:genetics / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
chemical_list: D051246:Glucose Transport Proteins, Facilitative; D051272:Glucose Transporter Type 1; D051273:Glucose Transporter Type 2; D012333:RNA, Messenger; C495679:Slc2a1 protein, rat; C495683:Slc2a2 protein, rat; C495676:Slc5a1 protein, rat; D051269:Sodium-Glucose Transporter 1; D000254:Sodium-Potassium-Exchanging ATPase; D005947:Glucose