Z Gastroenterol 2004; 42 - 10
DOI: 10.1055/s-2004-827114

Localization of aquaporins in patients with different duodenal disorders

B Bódis 1, O Karádi 1, T László 2, G Nagy 3, P Németh 3, G Mózsik 1, B Hunyady 1
  • 11st Department of Medicine, University Medical School of Pécs, Pécs
  • 2Department of Pathology, University Medical School of Pécs, Pécs
  • 3Immunological and Biotechnological Department, University Medical School of Pécs, Pécs

The family of water channeling molecules – named aquaporins (AQP) – was discovered during the last decade. The expression of various aquaporins (AQP1, AQP3, AQP4, AQP8 and recently AQP9) was demonstrated in the small intestine in animals and human. However, the exact localization of aquaporins in human duodenum in various disorders has not been reported.

The aim of this study was to determine the localization of AQP1 and AQP4 in duodenal biopsy samples of patients suffering different diseases (e.g. duodenitis, ulcer disease and total villous atrophy). Materials and methods: Highly specific monoclonal antibody family was developed against AQP1 and AQP4 molecules (Nagy et al., Pathology Oncology Research Vol 8, No 2, 115–124, 2002). The localization of these aquaporins was demonstrated by immunohistochemistry of formaldehyde-fixed and paraffin-embedded human duodenal biopsy samples.

Results: 1) In healthy duodenal tissues capillaries expressed AQP1 and we could demonstrate only a week staining of AQP4 in the mucosal layer. 2) In duodenitis and ulcer we could detect stronger AQP1 staining in the capillaries. In ulcer samples AQP4 was not expressed in the glands. 3) In the case of total villous atrophy an over expression of AQP4 can be seen forming a homogenous layer on the mucosal surface.

Conclusions: In various duodenal diseases the expression of AQP1 and AQP4 shows specific patterns, which might be in connection with mucosal osmotic regulation. This study was supported by the grant of OTKA (F 037639/2002).