Altered expression of sodium transporters in the excretory duct-ligated submandibular gland in rat

ABSTRACT

atrophy frequently occurs and the salivary secretory activity is significantly decreased in various salivary glandular diseases, their underlying molecular mechanisms have not been established. The present study was aimed to increase our understanding of functional alterations associated with pathological acinar atrophy. Male Sprague-Dawley rats weighing 180-200g were used. Their left submandibular ducts were ligated for 1 week, and the expression of sodium transporters related to the salivary formation was determined in the gland. The ligated gland was significantly decreased in its weight. The expressions of alpha1 and beta1 subunits of Na, K-pump determined by Western blot analysis were increased in the experimental group. Accordingly, the catalytic activity of Na, K-pump was increased. The expressions of alpha, betaand gammasubunits of ENaC were increased. The expression of TSC was also increased. The mRNA expression of mineralocorticoid receptor determined by reverse transcription-polymerase chain reaction was decreased in the experimental group. These results suggest that the changes in sodium transporters are causally related with an increased intraluminal pressure in the salivary duct in the ligated gland.