Na+-glucose cotransporter is also expressed in mesothelium of species with thick visceral pleura.
Molecular evidence for Na+-glucose cotransporter (SGLT1) in rabbit pleural mesothelium has been recently provided, confirming earlier functional findings on solute-coupled liquid absorption from rabbit pleural space. In this research we checked whether SGLT1 is also expressed in pleural mesothelium of species with thick visceral pleura, which receives blood from systemic circulation, but drains it into pulmonary veins. To this end immunoblot assays were performed on total protein extract of scraped visceral and parietal mesothelium of lambs and adult sheep, and of a human mesothelial cell line. All of them showed SGLT1 specific bands. Moreover, confocal immunofluorescence images of lamb pleural mesothelium showed that SGLT1 is located in apical membrane. Therefore, a solute-coupled liquid absorption should also occur from pleural space of species with thick visceral pleura. Because of this protein-free liquid entering interstitium between visceral mesothelium and capillaries, inherent Starling forces should be different than hitherto considered, and visceral pleura capillaries could absorb liquid even in these species.
Sironi
Chiara
C
Istituto di Fisiologia Umana I, Università di Milano, Via Mangiagalli 32, 20133 Milano, Italy.
Bodega
Francesca
F
Porta
Cristina
C
Monaco
Ario
A
Zocchi
Luciano
L
Agostoni
Emilio
E
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D002461:Cell Line, Transformed; D004848:Epithelium / Q000378:metabolism*; D015870:Gene Expression / Q000502:physiology*; D006801:Humans; D010994:Pleura / Q000166:cytology*; D012756:Sheep; D051247:Sodium-Glucose Transport Proteins / Q000378:metabolism*
D051247:Sodium-Glucose Transport Proteins