Streptozotocin- induced changes of aquaporin 1 and 4, oxidative stress
and autophagy in submandibular and parotid salivary glands and the
possible ameliorative effect of intermittent fasting on these changes:
immunohistochemical and molecular study in rats.
Abstract
Salivary glands are greatly responsible for maintaining oral tissue
homeostasis by the secretion of saliva. This study was designed to
investigate the changes of aquaporin 1 and 4, oxidative stress and
autophagy in submandibular and parotid salivary glands of diabetic rats
and the possible ameliorative effect of intermittent fasting on these
changes. Fifty adult male rats were divided into control and
experimental groups. Experimental diabetes was induced by a single
intraperitoneal injection of streptozotocin. After diabetic induction,
the experimental group was divided into two groups (diabetic without
intermittent fasting and diabetic with intermittent fasting). Animals
were sacrificed two and four weeks after induction of diabetes.
Intermittent fasting significantly decreased malondialdehyde and
significantly elevated reduced glutathione (GSH) in the submandibular
and parotid glands compared to those in diabetic rats. The salivary
secretions were also significantly spared histologically in diabetics
with intermittent fasting groups. As well, intermittent fasting
up-regulated aquaporin 1 in both glands, while aquaporin 4 was only
elevated in submandibular gland. Immunolocalization and gene expression
of Lc3-II was higher in diabetic salivary glands than in fasting glands.
In conclusion, these findings highlight the pathological role of
autophagy in diabetic sub-mandibular and parotid glands and provide
potential target for therapeutic role of intermittent fasting to
ameliorate submandibular and parotid glands dysfunction in type I
diabetes mellitus.