Increased SGLT1 expression in salivary gland ductal cells correlates with hyposalivation in diabetic and hypertensive rats.
BACKGROUND
Oral health complications in diabetes and hypertension include decreased salivary secretion. The sodium-glucose cotransporter 1 (SGLT1) protein, which transports 1 glucose/2 Na+/264 H2O molecules, is described in salivary glands. We hypothesized that changes in SGLT1 expression in the luminal membrane of ductal cell may be related to an altered salivary flow.


RESULTS
By immunohistochemistry, we investigated SGLT1 expression in ductal cells of parotid and submandibular glands from Wistar Kyoto rats (WKY), diabetic WKY (WKY-D), spontaneously hypertensive rats (SHR) and diabetic SHR (SHR-D), as well as in parotid glands from WKY subjected to sympathetic stimulation, with or without previous propranolol blockade. Diabetes and hypertension decreased the salivary secretion and increased SGLT1 expression in the luminal membrane of ductal cells, and their association exacerbated the regulations observed. After 30 min of sympathetic stimulation, SGLT1 increased in the luminal membrane of ductal cells, and that was blocked by previous injection of propranolol.


CONCLUSIONS
SGLT1 expression increases in the luminal membrane of salivary gland ductal cells and the salivary flow decreases in diabetic and hypertensive rats, which may be related to sympathetic activity. This study highlights the water transporter role of SGLT1 in salivary glands, which, by increasing ductal water reabsorption, may explain the hyposalivation of diabetic and hypertensive subjects.
Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas - Área de Fisiologia e Farmacologia Av, Pará, 1720 Campus Umuruama, CEP: 38400-902 Uberlândia-MG, Brazil. robinsonsabino@gmail.com.
Robinson
R
Sabino-Silva
Maristela Mitiko
MM
Okamoto
Aline
A
David-Silva
Rosana Cristina
RC
Mori
Helayne Soares
HS
Freitas
Ubiratan Fabres
UF
Machado