Stereology and ultrastructure of the salivary glands of diabetic Nod mice submitted to long-term insulin treatment

Comparative Study of Cytokeratin Immunostaining of Parotid Gland Parenchyma in Normal, Diabetic, and Excretory Duct Ligation of Mongrel Dogs

OBJECTIVES

 The present study aimed to give a glimpse of the normal distribution of intermediate filaments within the parotid gland parenchyma of mongrel dogs and to reveal the pathological changes that may occur as a result of the effects of diabetes mellitus or atrophy of the gland caused by the ligation of the excretory duct to discover whether there is a similarity in these pathological behaviors.

MATERIALS AND METHODS

 Twelve healthy mongrel dogs were used in the experiment and were divided into three groups: group I (the control group), group II (dogs with alloxan-induced diabetes), and group III (dogs with the right-side duct-ligated parotid gland). The dogs were sacrificed 45 days after the parotid excretory duct were tied. The right parotid gland of all groups was dissected and prepared for histological and immunohistochemical expression of cytokeratin 17 assay.

RESULTS

 Histological findings confirmed that the parotid gland parenchyma of the diabetic group had glandular atrophy characterized by the loss of gland structure, degenerated acini, and dilatation of the duct system. Moreover, there is a predominance of the fibrous component with the presence of fat cells within the gland compartments. On the contrary, the excretory duct-ligated group undergoes severe glandular atrophy of the previous character with the presence of duct-like structure as well as extravasation and vasodilatation. Immunohistochemical expression of cytokeratin 17 in control parotid using an immunoperoxidase technique showed that cytokeratin expression varies from negative to mild in all ducts and some serous acinar cells. The gland parenchyma of the diabetic group showed mild to strong cytokeratin expression of duct cells more concentrated in the apical part with moderate to strong expression of diffuse type in some serous acini. The intensity of cytokeratin 17 in gland compartments of the excretory duct-ligated group revealed a variation in expression that ranged from negative to strong diffuse staining throughout the gland.

CONCLUSION

 The severity and prevalence of cytokeratin 17 in our results are predictive of the pathological influence of both diabetes mellitus and duct ligation on the cytokeratin intracellular filaments of the salivary gland parenchyma in a different way that interferes with saliva production and/or secretion leading to xerostomia.

Immunohistochemical Evaluation of the Pathological Effects of Diabetes Mellitus on the Major Salivary Glands of Albino Rats

OBJECTIVES

 Diabetes mellitus (DM) is a notorious chronic disease characterized by hyperglycemia. Our study aimed to determine the expression of cytokeratin 17 (CK17) in all major salivary glands of diabetic albino rats to provide more information about the pathological effects of DM on the intracellular structures of the gland parenchyma.

METHOD

 Twenty male adult albino rats were utilized in the experiment and divided into two equal groups, group 1 (control rats) and group 2 (diabetic rats). The animals were sacrificed 45 days after diabetes induction. The major salivary gland complex of all groups was dissected and prepared for evaluation by histological and immunohistochemical expression of CK17.

RESULTS

 Histological results prove that the salivary gland parenchyma of diabetic group undergo gland atrophy characterized with the presence of degenerated acini, dilated duct system, and presence of duct-like structure with predominance of fibrous tissue compartment and discrete fat cells. Immunohistochemical expression of CK17 of major salivary gland of control group revealed negative to diffuse mild expression in all duct cells and some serous acinar cells, whereas mucous acini were negatively stained. On the other hand, major salivary gland parenchyma of diabetic group demonstrated mild to strong expression of duct cells more concentrated at their apical part with moderate to strong expression of some serous acini of diffuse type, whereas mucous acini of both submandibular gland and sublingual gland (SLG) were negatively stained.

CONCLUSION

 The severity and prevalence of CK 17 in our results are predictive of the pathological influence of the DM that interferes with saliva production and/or secretion leading to dry mouth. Also, SLG of diabetic rats showed inspiratory changes in immunohistochemical expression in CK17 in spite of they did not show an effect of lesser degree in the routine hematoxylin and eosin histological study.

Fasting salivary glucose levels is not a better measure for identifying diabetes mellitus than serum or capillary blood glucose levels: comparison in a Ghanaian population

Aims/introduction

We compared the diagnostic performance and correlation between salivary, serum and capillary blood glucose of diabetes and non-diabetes patients. Early detection of diabetes mellitus (DM) contributes to the prevention of complications and management.

Materials and methods

This case-control study was conducted among a total of 138 participants comprising 79 newly diagnosed diabetes patients (cases) and 59 non-diabetes patients (controls). Fasting salivary glucose (FSLG), fasting serum glucose (FSEG) levels and fasting capillary whole blood glucose (FCWBG) level were assayed for each participant.

Results

The mean FSLG, FSEG and FCWBG levels were significantly higher among the cases compared to controls (p < 0.0001). There was a significant mean difference between the levels of FSLG vs. FSEG (p < 0.0001) and FSLG vs. FCWBG (p < 0.0001) but not levels of FSEG vs. FCWBG (p > 0.05) in both cases and controls. A positive correlation was observed between FSLG and FSEG (r = 0.89; p < 0.0001) and FCWBG (r = 0.87; p < 0.0001). At the cut-off value >6.8 mmol/l for FSEG, a sensitivity of 99%, specificity of 100.0% and area under the curve (AUC) of 98.8% was observed for predicting DM while a sensitivity of 80%, specificity of 95% and AUC of 91.0% was observed for FSLG at a cut-off value >0.5 mmol/l. At the cut-off value >6.9 mmol/l for FCWBG, a sensitivity of 100.0%, specificity of 100.0% and AUC of 100.0% was observed for predicting DM.

Conclusion

Fasting salivary glucose (FSLG) levels increased with increasing blood glucose levels. However, it does not generate enough diagnostic and predictive accuracy compared to capillary whole blood glucose which less invasive.

Postnatal changes in the development of rat submandibular glands in offspring of diabetic mothers: Biochemical, histological and ultrastructural study

Development and maturation of submandibular salivary glands are influenced by intrauterine diabetic environment. Several studies investigated the effects of diabetes on the salivary glands. However, the effects of maternal diabetes on the submandibular glands of the offspring was not properly examined. Therefore, the present study was designed to describe the changes in the development of the submandibular glands of the offspring of diabetic mothers. The submandibular glands of the offspring of Streptozotocin (STZ)-induced diabetic female rats were examined at two and four weeks after birth. Detection of mRNA demonstrated that maternal diabetes affects the level of different indicators. The reduction of expression of epidermal growth factor (EGF); a protein mitogen, cytokeratin 5 (CK5); an epithelial cell progenitor, CK7 and aquaporin 5 (AQP5); differentiation markers and B cell lymphoma 2 (Bcl2); an antiapoptotic marker were found. Increase in Bcl2-associated X protein (Bax); an apoptotic marker was detected. These changes indicate their effects on saliva secretion, glands tumorigenesis, growth of normal oral flora and oral microbes, with decreased protein synthesis and production of xerostomia and dental caries. Loss of normal glandular architecture, significant increase in fibrosis, by the detection of collagen fibers, and stagnation of secretory granules were found with atrophic changes in the acinar cells. Marked defect of polysaccharides in the acinar cells, denoting functional changes, was manifested by significant reduction of the intensity of periodic acid-Schiff (PAS) reaction. The positive immunoreactivity of caspase-3, denoting cellular apoptosis, and minimal reaction of alpha-smooth muscle actin (α SMA) and proliferating cell nuclear antigen (PCNA) were evident in the offspring of diabetic mothers. We conclude that maternal diabetes produces degenerative effects in the structure and function of the submandibular salivary glands of the offspring, reflecting possible influences on their secretory activity affecting oral and digestive health.

Salivary glucose levels and oral candidal carriage in Type 2 diabetics

Background

To assess the correlation between salivary glucose and blood glucose levels in diabetics and non diabetics and to study the association between salivary glucose levels and oral candidal carriage in patients with Type 2 diabetes mellitus.

Material and method

The study sample was divided into two groups, control and study group. The study group was again divided into two separate groups controlled diabetics and uncontrolled diabetics. Blood and saliva samples (for fasting and postprandial) were taken from each individual.

Results

The salivary glucose levels, highly correlated with blood glucose levels in both diabetic as well as non diabetics subjects. Salivary candidal carriage was more in oral cavity of Type 2 diabetic subjects than control subjects.

Conclusion

Saliva has the potential to be used as a noninvasive tool to monitor glycemic status of diabetic patients.

The immunomodulation to diabetes control: New proposals for the reversion of this disease

The diabetes mellitus is a metabolic disorder, characterized by the hyperglycemia with deficiency in the use of carbohydrates, fats and proteins, resultant of the impairment in secretion and/or insulin action. Severely, the type 1 diabetes provokes the compromise of several organs, causing different disorders and until death of patient. In this way, the literature has shown the general treatments for the type 1 diabetes and currently the focus in immunotherapy and/or immunomodulation, to control of this hyperglycemic condition. The use of new therapies is necessary due to the high increase of incidence of this disease around the world. Recent studies showed an increase of 40% in the cases since 1997. This disease affects different organs, including the glandular tissues, mainly the pancreas. Despite all therapies for diabetes control, the damages occurred remain irreversible. Thus, in addition to general treatments, the use of immunotherapy may open new perspectives for treatment of this disease. Within this aspect, the anti-CD3 monoclonal antibodies may be effective, mainly by protect and maintain the pancreatic acinar cells. Thus, these treatments based in the immunomodulation can be an option for diabetes control and to reverse the damage caused by this disease.

Diabetes causes morphological changes in human submandibular gland: a morphometric study

BACKGROUND

Dataon structural alterations in human diabetic salivary glands are scanty and conflicting. The goal of this study is based on the evaluation of the morphological changes in submandibular glands of subjects with well-controlled diabetes and without evident salivary malfunctions.

METHODS

Submandibular gland pieces from diabetic and non-diabetic patients were fixed, dehydrated, and processed to obtain sections for light and electron microscopy. Randomly selected micrographs were statistically analyzed to reveal variations in serous acini.

RESULTS

Morphometrical evaluation allowed us to reveal significant changes such as enlargement of acinar and granule size, reduction of mitochondrial size, increased density of microbuds and protrusions along luminal membranes.

CONCLUSIONS

The results indicate that diabetes affects submandibular gland structure even when glandular function appears unaltered and suggest that morphological changes reflect functional changes chiefly regarding the secretory activity.

IGF-I and INS receptor expression in the salivary glands of diabetic Nod mice submitted to long-term insulin treatment

This work aimed to characterize the IGF-I and INS receptor expression in the salivary glands of Nod mice, correlating to therapeutic effects of insulin treatment on these receptors. Nod mice were divided into: Groups 1 and 2 (diabetic), Groups 3 and 4 (diabetic with insulin treatment) and Group 5 (non-diabetic). Fragments from the salivary glands were processed for immunohistochemical analysis. The results showed that the prolonged diabetic state led to a steadily increased IGF-I receptor expression. INS receptor expression was gradually decreased. It was concluded that not only was the IGF-I receptor expression affected by the diabetic state but also the INS receptor expression. The period of the diabetic state was directly related to changes in the expression of these receptors. In spite of the insulin treatment having recovered the glycaemic levels, the expression of INS and the IGF-I receptors did not reach the standard level, which certainly hampered glandular function.

GLP-1 expression in von Ebner's gland of diabetic rats

GLP-1, a peptidergic endocrine hormone, which associate with appetite control, glucose homeostasis and satiety. It might play an important role in the gustatory system. We tried to investigate the expression of GLP-1 in von Ebner's gland of diabetic and control rats, and the ultrastructure changes on von Ebner's gland of diabetes rats. GLP-1 expression in von Ebner's gland was evaluated by immunohistochemistry. The number of GLP-1 positive cells in diabetic rat von Ebner's gland was significantly higher than that in normal controls. Electron micrographs showed that a series of pathologic changes in von Ebner's gland of diabetes rats. The results suggest that GLP-1 have some effects within the gustatory systems, and elevated von Ebner's gland GLP-1 expression may be one cause of diabetic taste impairment.

Dipeptidyl peptidase IV inhibitor improves the salivary gland histology of spontaneously diabetic mice

OBJECTIVES

The incretin-based therapy might be effective in patients possessing certain levels of preserved pancreatic beta-cells. However, doubts still exist regarding the efficacy of this atment in the recovery of tissues damaged by type 1 diabetes. Thus, the objective of this study was to evaluate the treatment with MK0431 in salivary glands of spontaneously diabetic mice, focusing mainly on the possible therapeutic and hypoglycaemic effects of this dipeptidyl peptidase IV inhibitor in the recovery of these salivary tissues.

METHODS AND RESULTS

Twenty mice were divided into two groups of 10 animals each: group I (NOD diabetic/untreated) and group II (NOD diabetic MK0431/treated). The group II was treated during 4 weeks with MK0431 mixed in the food. The group I was maintained in the same way without receiving, however, any treatment. Glucose levels were monitored during treatment and salivary glands samples were collected at the end of treatment for the histological examination under both transmitted and polarized light microscopy. High glucose levels were observed in untreated animals, while in animals with treatment, reduction of these levels was observed. Tissue restructuring was also observed in animals submitted to therapy with MK0431, mainly in relation to the attempt to extracellular matrix reorganization.

CONCLUSIONS

According to results, the treatment with this dipeptidyl peptidase IV inhibitor contributed to the general homeostasis of the organism and to the reestablishment of both epithelial and stromal compartments which were damaged by the hyperglycaemic condition, demonstrating that the incretin-based therapy may be an important complementary treatment for the type 1 diabetic condition.

Effects of anti-CD3 monoclonal antibody in salivary glands of spontaneously diabetic mice

BACKGROUND

Diabetes mellitus results in many complications, also compromising the salivary glands. The current treatment for this condition should be a substituting method to exogenous insulin. In this aspect, the immunotherapy has been tested, but, it can be inefficient as an agent for the control of damage caused by diabetes. Thus, the aim of this study was to evaluate the anti-CD3 monoclonal antibody as alternative immunotherapy in the recovery of salivary glands of spontaneously diabetic NOD (nonobese diabetic) mice.

METHODS

NOD mice were divided into two groups of 10 animals: group I (untreated diabetic mice) and group II (anti-CD3-treated diabetic mice). After treatment, the samples of salivary glands were collected for histological examination under both transmitted and polarized light microscopy.

RESULTS

Alterations in tissue architecture; increase in extracellular matrix and presence of inflammatory process were observed in untreated animals. Recovery of the salivary acinar cells occurred in treated animals. The parotid glands demonstrated a smaller amount of collagen fibers and were not observed severe inflammatory processes.

CONCLUSION

These results indicate that immunotherapy contributed to reestablishment of tissue damaged by the hyperglycemic condition, demonstrating that the immunomodulation plays an important role in the recovery of salivary glands.

Estrogen and insulin replacement therapy modulates the expression of insulin-like growth factor-I receptors in the salivary glands of diabetic mice

Diabetes mellitus results in various complications, also compromising the salivary glands. Hormone levels and interactions with cellular receptors are altered, intensifying the damage caused by this disease. Hormone replacement therapy alone or combined with other treatments may reverse this damage, but doubts still exist regarding the efficacy of this procedure. The objective of this study was to evaluate the effect of estrogen replacement therapy combined with insulin treatment on salivary secretory cells and on the expression of insulin-like growth factor (IGF)-I receptors in salivary glands of spontaneously diabetic (NOD) mice. Twenty-five mice were divided into five groups of five animals each: group I (NOD diabetic), group II (NOD diabetic treated with insulin), group III (NOD diabetic treated with estrogen), group IV (NOD diabetic treated with insulin and estrogen), and group V (control Balb/c mice). Group II received insulin, group III received estrogen, and group IV received insulin plus estrogen administered daily for 20 days. Groups I and V received saline for the same period of time to simulate treatment. Glucose and estrogen levels were monitored during treatment, and salivary gland samples were collected at the end of treatment for stereological analysis and immunofluorescence detection of IGF-I receptors. Tissue restructuring and regulation of IGF-I receptors expression were observed in animals submitted to estrogen replacement therapy plus insulin. Estrogen effectively promoted the recovery of salivary secretory cells, demonstrating that this hormone alone, and especially when combined with insulin, might be important for the reversal of hyperglycemia-induced tissue injury.

Short-term stromal alterations in the rat ventral prostate following alloxan-induced diabetes and the influence of insulin replacement

The stromal microenvironment is pivotal to prostate physiology and malign transformation. Diabetes leads to testosterone withdrawal and affects the prostate stromal compartment and smooth muscle cells in a similar way to that observed after castration. However the response of these cells and their involvement in extracellular matrix remodeling is not satisfactorily understood. We investigated the changes caused in the short term (one week) by alloxan-induced diabetes in the stromal components of the rat ventral prostate (VP) with an emphasis on morphological alterations of stromal cells, their conversion to a myofibroblast phenotype and the remodeling of extracellular matrix and the influence of insulin therapy. Adult male Wistar rats were assigned into untreated diabetic (n=12), insulin-treated (n=8) diabetic and control (n=10) groups. Diabetes was induced by means of the injection of alloxan (40 mg/kg b.w.), while the control animals received saline solution only. Insulin (5 UI) was administered daily for one week after diabetes diagnosis. Testosterone and estrogen plasma levels were determined. VP was analyzed using transmission electron microscopy. The main stromal cells were identified by means of light microscopy, using immunocytochemistry for specific markers - vimentin for fibroblasts, α-actin for smooth muscle cells (smc) and vimentin/calponin for myofibroblasts, following the estimation of their relative frequency and absolute volume by means of stereology. After one week diabetes led to a marked decrease in testosterone levels and an atrophy of about 35% in the VP. The relative frequency of smc and collagen fibers increased in the VP of diabetic rats but their absolute weight remained unchanged. Experimental diabetes promptly altered smc morphology which assumed at the ultrastructural level a shrunken appearance with the approximation of cytoplasmic dense bodies and also exhibited a decreased immunoreactivity to calponin. The conversion of stromal cells to a myofibroblast phenotype did not occur in alloxan-induced diabetes, as evaluated by double immunoreaction to calponin and vimentin. Insulin treatment maintained testosterone levels and preserved at least partly the cell morphology and collagen fiber organization of the prostate stroma in short-term diabetes. The apparent collagen increase observed by means of microscopic analysis in the stromal prostate compartment in the short term after diabetes is mainly associated with gland atrophy and does not involve the formation of new collagen fibers, the generation of myofibroblast-like cells or the acquisition of a secretory phenotype by stromal cells.