Lysosomal Exoglycosidase Profile and Secretory Function in the Salivary Glands of Rats with Streptozotocin-Induced Diabetes.

Mateusz Maciejczyk,Julita Szulimowska,Adrian Chabowski,Halina Car,Anna Zalewska,Małgorzata Knaś,Jerzy Robert Ładny,Anna Klimiuk,Wiesława Niklińska,Agnieszka Kossakowska

doi:10.1155/2017/9850398

Abstract

Before this study, there had been no research evaluating the relationship between a lysosomal exoglycosidase profile and secretory function in the salivary glands of rats with streptozotocin- (STZ-) induced type 1 diabetes. In our work, rats were divided into 4 groups of 8 animals each: control groups (C2, C4) and diabetic groups (STZ2, STZ4). The secretory function of salivary glands—nonstimulated and stimulated salivary flow, α-amylase, total protein—and salivary exoglycosidase activities—N-acetyl-β-hexosaminidase (HEX, HEX A, and HEX B), β-glucuronidase, α-fucosidase, β-galactosidase, and α-mannosidase—was estimated both in the parotid and submandibular glands of STZ-diabetic and control rats. The study has demonstrated that the activity of most salivary exoglycosidases is significantly higher in the parotid and submandibular glands of STZ-diabetic rats as compared to the healthy controls and that it increases as the disease progresses. Reduced secretory function of diabetic salivary glands was also observed. A significant inverse correlation between HEX B, α-amylase activity, and stimulated salivary flow in diabetic parotid gland has also been shown. Summarizing, STZ-induced diabetes leads to a change in the lysosomal exoglycosidase profile and reduced function of the salivary glands.

Highlights

Diabetes mellitus (DM) is a group of frequent metabolic disorders characterized by abnormalities in insulin secretion and/or insulin action [1]
We have found that HEX A-specific activity in rats with experimentally induced type 1 diabetes was significantly lower in the 2nd week of the study, and in the 4th week, it was considerably higher in parotid glands of these rats compared to their submandibular glands (Figure 1(b))
In the submandibular and parotid glands of rats with STZ-induced diabetes, acinar cells showed a degenerative change in the form of vacuolation. In both the 2nd and 4th weeks of the experiment, the number of vacuoles was higher in the parotid gland as compared to the submandibular gland (Figure 5, Table 3). This is the first study that evaluated the relationship between lysosomal exoglycosidase profile and secretory function of Salivary amylase mg/100 mg total protein

Summary

Introduction

Diabetes mellitus (DM) is a group of frequent metabolic disorders characterized by abnormalities in insulin secretion and/or insulin action [1]. Salivary glycoproteins (e.g., immunoglobulins, lactoferrin, and salivary peroxidase system) and glycolipids participate in the interaction between salivary proteins, carbohydrates, oral bacteria, and viruses and thereby play an important role in the oral immune defense mechanisms [7]. Salivary glycoconjugates such as mucins (MUC1, MUC4, MUC5B, MUC7, and MUC19), proline-rich glycoproteins (PRGs), and kallikrein may ensure the appropriate hydration of the oral mucosa and maintain the proper pH of the stimulated and nonstimulated saliva [8, 9]

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