Isoforms of Na+, K+-ATPase in human prostate; specificity of expression and apical membrane polarization

• Mobasheri, A. ^[1] ; Oukrif, D. ^[2] ; Dawodu, S.P. ^[2] ; Sinha, M. ^[2] ; Greenwell, P. ^[2] ; Stewart, D. ^[5] ; Djamgoz, M.B.A. ^[5] ; Foster, C.S. ^[1] ; Martín-Vasallo, P. ^[3] ; Mobasheri, R. ^[4]
  1. [1] University of Liverpool

     University of Liverpool

     Reino Unido

     
  2. [2] University of Westminster

     University of Westminster

     Reino Unido

     
  3. [3] Universidad de La Laguna

     Universidad de La Laguna

     San Cristóbal de La Laguna, España

     
  4. [4] East Surrey Hospital

     East Surrey Hospital

     Reigate and Banstead District, Reino Unido

     
  5. [5] Department of Biology, Imperial College of Science, Technology and Medicine, London, United Kingdom

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• Localización: Histology and histopathology: cellular and molecular biology, ISSN-e 1699-5848, ISSN 0213-3911, Vol. 16, Nº. 1, 2001, págs. 141-154
• Idioma: inglés
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  • The cellular distribution of Na+, K+-ATPase subunit isoforms was mapped in the secretory epithelium of the human prostate gland by immunostaining with antibodies to the a and 13 subunit isoforms of the enzyme. Immunolabeling of the aI, 131 and 132 isoforms was observed in the apical and lateral plasma membrane domains of prostatic epithelial cells in contrast to human kidney where the a1 and 131 isoforms of Na+, K+- ATPase were localized in the basolateral membrane of both proximal and distal convoluted tubules. Using immunohistochemistry and PCR we found no evidence of N a+, K+ -ATPase a2 and a3 isoform expression suggesting that prostatic Na+, K+ -ATPase consists of a1/B1 and al/B2 isozymes. Our immunohistochemical findings are consistent with previously proposed models placing prostatic Na+, K+ -ATPase in the apical plasma membrane domain. Abundant expression of Na+, K+- ATPase in epithelial cells lining tubulo-alveoli in the human prostate gland confirms previous conclusions drawn from biochemical, pharmaco logical and physiological data and provides further evidence for the critical role of this enzyme in prostatic cell physiology and ion homeostasis. Na+, K+-ATPase most likely maintains an inwardly directed Na+ gradient essential for nutrient uptake and active citrate secretion by prostatic epithelial ce lls. Na+, K+-ATPase may also regu late lumenal Na+ and K+, major counter-ions for citrate.