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Introduction: The aim of the present study was to evaluate the possibility of making use of the specific activity of N-acetyl-β-hexosaminidase, its isoenzymes and β-glucuronidase--potential indicators of salivary gland damage--in the detection of early onset of salivary gland impairment in RA, which is also demonstrated by xerostomia., Material/methods: For this purpose RA xerostomic salivary patients (unstimulated salivary flow >0.1 mL/min) were compared with RA xerostomic hyposalivary patients (unstimulated salivary flow ≤0.1 mL/min), RA patients without xerostomia (unstimulated salivary flow >0.1 mL/min) and generally healthy controls (unstimulated salivary flow >0.1 mL/min, without xerostomia). Salivary N-acetyl-β-hexosaminidase, its isoenzymes A and B, and β-glucuronidase specific activity were determined according to the Marciniak et al. method. The protein content in the unstimulated saliva was determined by the bicinchoninic acid method., Results: In xerostomic rheumatoid arthritis patients, the specific activity of salivary β-glucuronidase and isoenzyme A was significantly higher than in the healthy controls but the specific activity of salivary N-acetyl-β-hexosaminidase, its isoenzyme B and β-glucuronidase was significantly lower than in xerostomic hyposalivary rheumatoid arthritis patients., Conclusions: We suggest a simple, safe and cheap method for the determination of exoglycosidases as a useful tool for the diagnosis of early stages of salivary gland involvement in rheumatoid arthritis.

Objective: This investigation was a basal study that used a mouse model of xerostomia to identify protein biomarkers of xerostomia in saliva. We identified genes expressed differently in parotid glands from non-obese diabetic mice with diabetes and those from control mice; subsequently, we investigated expression of the proteins encoded by these genes in parotid glands and saliva., Materials and Methods: DNA microarray and real-time PCR analyses were performed to detect differences between NOD/ShiJcl and C57BL/6JJcl (control) female mice in gene expression from parotid glands or parotid acinar cells. Subsequently, protein expression was assessed using immunoblotting and immunohistochemistry. Similarly, enzyme activity in saliva was assessed using zymography., Results: Based on gene expression analyses, Chia expression was higher in diabetic mice than non-diabetic mice and control mice; similarly, expression of chitinase, the protein encoded by Chia, was higher in diabetic mice. Saliva from NOD/ShiJcl mice had more chitinase than saliva from control mice., Conclusions: Chitinase was highly expressed in parotid acinar cells from diabetic mice compared with non-diabetic and control mice. Increased chitinase expression and enzyme activity may characterize the autoimmune diabetes in mice; however, further investigation is required to assess its use as a biomarker of xerostomia in humans., (© 2012 John Wiley & Sons A/S.)

The authors have studied the "sympathetic like" side effect of pilocarpine after single injection (1 mg/100 g b.w., i.p.) of the drug. They developed a system for the continuous automatic recording the amylase activity of the saliva secreted by the parotid glands of rats, "in situ". Pilocarpine stimulus was characterized by a peak in amylase activity--regularly observed in the first 40-60 min--which was additive to the cholinergic amylase secretory response. After this the amylase secretion was continued with lower activity. The role of a beta-adrenergic component in the pilocarpine stimulus appears to be supported by the finding that propranolol (2.5 mg/100 g b.w., i.p.) pretreatment applied 30 min prior to the pilocarpine stimulus prevented the appearance of the characteristic amylase peak. These data support that the beta-adrenergic side effect triggering the periodical synthesis of export proteins during the course of pilocarpine treatment accounts for the selative efficiency of pilocarpine in the therapy of xerostomia.

The volume of the secretion of saliva is decreased in elderly people. The volume of salivary secretion varies directly with acid DNase activity. Neutral DNase activity, however, shows no significant variation.

Saliva and serum lysozyme, immunoglobulin, albumin, and total protein levels were monitored in thirty patients with cancer of the head or neck before, during, and after radiotherapy and compared with those of a group of non-irradiated noncancer control subjects. The mean volume-based saliva lysozyme and total protein concentrations were significantly higher in the cancer patients before radiotherapy than in the control group. During radiotherapy, the mean volume-based concentrations of all protein components assayed increased as the saliva flow rate decreased. Protein-based ratios of saliva albumin, IgG, and lysozyme and the ratio of IgG/IgA increased as the xerostomia intensified. Ratios of saliva total protein and IgA to flow rate paralleled the flow rate decrease. Such increased concentrations in saliva immunoproteins were offset, however, by a greater than 93 per cent reduction in total saliva output. This reduced saliva output, therefore, resulted in an immunoprotein deficit. There were no significant differences between the mean serum lysozyme levels of the cancer and control groups at any point of comparison. The mean serum immunoglobulin concentrations in the cancer patients before radiotherapy were significantly higher than those in the control group. During radiotherapy, there was a decrease in the mean serum total protein, albumin, and immunoglobulin levels which reverted toward the pretreatment values during the postirradiation period.