Acta Physiologica 2009; Volume 197, Supplement 672
The 60th National Congress of the Italian Physiological Society
NA+-GLUCOSE COTRANSPORTER IS EXPRESSED BY ALVEOLAR EPITHELIAL TYPE I CELLS
Abstract number: P19
BODEGA1 F, SIRONI1 C, ARMILLI1 M, PORTA1 C, AGOSTONI1 E
1Dip. Fisiologia Umana, Universit degli Studi di Milanofrancesca.firstname.lastname@example.org
Functional evidence of Na+-glucose cotransport in rat lung has been provided. By autoradiography [3H]phloridzin binding has been found confined to alveolar type II cells in mouse and rabbit lungs.
In this research we checked by immunofluorescence whether Na+-glucose cotransporter (SGLT1) is also expressed in alveolar type I cells. To prevent artifacts two primary antibodies and different histological preparations were used. Lungs of anesthetized rats and lambs were fixed by paraformaldehyde, perfused in pulmonary artery, or instilled into a bronchus, respectively. Tissue blocks embedded in paraffin or frozen were then sectioned. Specific anti-SGLT1 antibodies for rat recognizing amino acid sequence 402-420, and 546-596 were used in both species; bound primary antibody was detected by secondary antibody conjugated to fluorescein isothiocianate or Texas red, respectively.
Results and conclusions:
In rats alveolar type I cells were identified by fluorescein labeled Erythrina cristagalli lectin. Sections were examined by confocal laser-scanning microscope. Both in rats and lambs most alveolar surface was stained by either anti-SGLT1 antibody; no labeling occurred in negative control sections. Hence, SGLT1 is also expressed in alveolar type I cells. This is functionally relevant because type I cells provide 95-97% of alveolar surface, and SGLT1, besides contributing to lung liquid removal under some circumstances, keeps low glucose concentration in lining liquid, which is useful to prevent lung infection.
To cite this abstract, please use the following information:
Acta Physiologica 2009; Volume 197, Supplement 672 :P19