Alteration of Ca²⁺‐ATPase activity in the homogenate, plasma membrane and microsomes of the salivary glands of streptozotocin‐induced diabetic rats

Abstract

Diabetes has been implicated in the dryness of the mouth, loss of taste sensation, sialosis, and other disorders of the oral cavity, by impairment of the salivary glands. The aim of the present study was to examine the plasma membrane, microsomal, and homogenate Ca(2+)-ATPase activity in the rat submandibular and parotid salivary glands of streptozotocin-induced diabetes. We have also examined the influence of the acidosis state on this parameter. Diabetes was induced by an intraperitoneal injection of streptozotocin and acidosis was induced by daily injection of NH(4)Cl. At 15 and 30 days after diabetes induction, the animals were euthanized and the submandibular and parotid salivary glands were removed and analyzed. Ca(2+)-ATPase (total, independent, and dependent) was determined in the homogenate, microsomal, and plasma membranes of the salivary glands of diabetic and control rats. Calcium concentration was also determined in the glands and showed to be higher in the diabetic animals. Ca(2+)-ATPase activity was found to be reduced in all cell fractions studied in the diabetic animals compared with control. Similar results were obtained for the submandibular salivary glands of acidotic animals; however in the parotid salivary glands it was found an increase in the enzyme activity.

Endoplasmic-Reticulum Calcium Depletion and Disease

“…Abnormal Ca 2þ signaling in the salivary glands leads to dryness of the mouth, loss of taste sensation, sialosis, and other disorders of the oral cavity (Nicolau et al 2009 ). Inhibition of this release with dantrolene reduces cell injury (Wei and Perry 1996).…”

Antioxidant enzymatic defense in salivary glands of streptozotocin‐induced diabetic rats: a temporal study

“…Numerous studies have reported the effects of experimental diabetes induced either by STZ or aloxan on the structure and functions of salivary glands of animals,7, 28, 29 including the antioxidant parameters status in various tissues 4, 7, 28. Studies based on aloxan‐diabetes rats showed significant decrease in DNA, RNA and amylase content in rat PA glands, increase in the peroxidase activity,7, 8, 30 increase of SGTL1 (responsible for the reabsorption of water in the duct cells) protein expression in ductal cells in diabetic rats,31 increase in the extracellular matrix proteins in PA,18 decrease in Ca‐ATPase, unbalance of Ca in the salivary gland32 and finally, an increase in the glycation of calmodulin 33. Despite all studies, the mechanism of the damages caused by diabetes is still not clear.…”

The Plasma Membrane Calcium ATPasesand Their Role as Major New Players in Human Disease

“…For example, basolateral membrane vesicles isolated from syncytiotrophoblast of insulin-dependent diabetic patients display increased PMCA activity (359), while reduced PMCA activity or expression has been identified in parotid and submandibular salivary glands, kidney, and brain synaptosomes of streptozotocin-induced diabetic rats (260,347,421).…”