Mapping Relative Differences in Human Salivary Gland Secretions by Dried Saliva Spot Sampling and nanoLC–MS/MS

Dried saliva spot sampling is a minimally invasive technique for the spatial mapping of salivary protein distribution in the oral cavity. In conjunction with untargeted nano‐flow liquid chromatography tandem mass spectrometry (nanoLC–MS/MS) analysis, DSS is used to compare the proteomes secreted by unstimulated parotid and submandibular/sublingual salivary glands. Two hundred and twenty proteins show a statistically significant association with parotid gland secretion, while 30 proteins are at least tenfold more abundant in the submandibular/sublingual glands. Protein identifications and label‐free quantifications are highly reproducible across the paired glands on three consecutive days, enabling to establish the core proteome of glandular secretions categorized into eight salivary protein groups according to their biological functions. The data suggest that the relative contributions of the salivary glands fine‐tune the biological activity of human saliva via medium‐abundant proteins. A number of biomarker candidates for Sjögren's syndrome are observed among the gland‐specifically expressed proteins, which indicates that glandular origin is an important factor to consider in salivary biomarker discovery.     

Radioisotopic and biochemical determination of salivary secretion after long term psychotropic therapy

The aim of this work was to investigate the effect of prolonged psychotropic therapy (neuroleptics and antidepressants over 5 yr on salivary secretion. The flow rate in the parotid and submandibular glands were measured separately by scintigraphy. Flow rates, total protein concentration and total IgA level were determined in the unstimulated saliva in 30 control subjects and 73 patients treated with psychotropic drugs. As evidenced by measurement of flow rates and scintigraphy, psychotropic therapy reduced the unstimulated salivary secretion from parotid glands and to a lesser extent from submandibular gland. The scintigraphic study showed a lower response to stimulation in patients than controls.     

The influence of medication on salivary flow of the elderly: preliminary study

doi:10.1111/j.1741‐2358.2009.00326.x
The influence of medication on salivary flow of the elderly: preliminary study Objective: This study was to evaluate the influence of medications on unstimulated and stimulated salivary flow in elderly men and women. Background: Several diseases and conditions are associated with decreasing salivary flow. Medications can be risk factors for hyposalivation due to the effect particular drug categories. Methods: Seventy‐five elderly of both gender (sixty years old or over) from the Geriatric Dental Clinic at the Federal Fluminense University Dental School, were interviewed about their health status and chronic use of medication. After the interview, unstimulated and stimulated saliva were collected from each subject. The collection time was five minutes, and the flow rate was calculated as ml/min. Results: The mean unstimulated salivary flow was 0.25 ml/min for women and 0.30 ml/min for men, while the mean for stimulated salivary flow was 1.23 ml/min for women and 1.31 ml/min for men, without both differences being non‐significant (p > 0.05). The difference between the mean production of unstimulated and stimulated salivary flow was statistically significant, regardless of gender (p < 0.01). A significant reduction of stimulated salivary flow was observed with the usage of cardiovascular agents (p < 0.05). Conclusion: Drugs used in cardiovascular disease influence the flow of stimulated saliva.     

Clinicopathological characteristics of immunoglobulin G4-related sialadenitis

IntroductionImmunoglobulin G4-related disease (IgG4-RD) is a newly recognized fibro-inflammatory condition. Forty-two cases with immunoglobulin G4-related sialadenitis (IgG4-RS) confirmed by histopathological and immunohistochemical assessment were studied to clarify the clinicopathologic characteristics of the salivary glands involved in IgG4-RS, especially the relationship between the histopathologic features and function of salivary glands or serum levels of IgG4.MethodsClinical, serologic, imaging and histopathological data of these cases were analyzed. CT volumes of submandibular, parotid, and lacrimal glands were calculated. The saliva flow rate was measured. Scintigraphy with 99mTc-pertechnetate was undertaken in 31 cases, and the concentration index (CI) and secretion index (SI) was calculated. Relationships between fibrosis severity and salivary gland function or serum IgG4 levels were analyzed.ResultsThe first symptom was swelling of bilateral submandibular or lacrimal glands. Physical examination showed multiple bilateral major salivary glands (including sublingual and accessory parotid glands) and lacrimal glands were enlarged in IgG4 RS. Multiple enlarged cervical lymph nodes were noted in 30 patients. Saliva flow at rest was lower than normal in 34 cases; stimulated saliva flow was lower than normal in 15 cases. Secretory function was reduced more severely in the submandibular glands than in the parotid glands. Serum levels of IgG4 were elevated in 95.2% of cases and 78.6% patients had increased IgE levels. Serum IgG4 level was higher and saliva secretion lower as glandular fibrosis increased.ConclusionsProminent changes in the morphology, histology, immunohistochemistry and secretion of the major salivary glands of IgG4-RS patients were accompanied by involvement of the lacrimal glands and cervical lymph nodes. Elevated IgE, allergic history, eosinophil infiltration suggest allergic reactions as a potential pathogenesis of IgG4-RS. Severity of glandular fibrosis correlated with salivary function and serum levels of IgG4.     

Characterization of mouse salivary glands by water content and type

The thermoanalytical analysis was applied to samples of sublingual, submandibular and parotid glands from sexually mature mice of both sexes. Findings indicated that the three salivary glands show a behaviour of water release characteristic for each type of gland. Derivative thermogravimetry curves concerned with the sublingual and parotid glands belonging to male and female subjects exhibited overlapped results. As regards submandibular gland, instead, some differences emerged between subjects of different sex. Water content and types in sublingual, submandibular and parotid glands were discussed and related to the different morphological expression, histochemical reactivity and chemical composition of these organ tissues.     

Use of Biometric Characteristics of Major Salivary Glands as a Baseline to Develop a Formula for the Quantitative Estimation of Posttraumatic Regeneration of Glandular Tissue

In experiments conducted on 903 rats, we studied the biometric characteristics of the major salivary glands (parotid, submandibular, and sublingual glands) during ontogenesis. We calculated the indices of nondirectional fluctuation asymmetry for the submandibular and sublingual glands and determined correlation coefficients and the coefficients of linear regression between salivary glands, rat body weight, and the weight of the femoral bone (the largest bone in the rat). The strongest correlation was found between the dry weight of the submandibular gland and the rat body weight. Mathematical analysis of the growth of the submandibular gland after sialotomy allowed us to derive a formula for the quantitative estimation of regeneration, taking into account the natural growth of the rat.     

Use of biometric characteristics of major salivary glands as a base line to develop a formula for the quantitative estimation of posttraumatic regeneration of glandular tissue

In experiments conducted on 903 rats, we have studied biometric characteristics of the major salivary glands (parotid, submandibular, and sublingual glands) during ontogenesis. We have calculated the indices of non-directional fluctuation asymmetry for the submandibular and sublingual glands and determined correlation coefficients and coefficients of linear regression between salivary glands, rat body weight, and the weight of the femoral bone (the largest bone in the rat). The strongest correlation was found between the dry weight of the submandibular gland and the rat body weight. Mathematical analysis of the growth of the submandibular gland after sialotomy allowed us to derive a formula for the quantitative estimation of regeneration, taking into account the natural growth of the rat.     

Developmental changes in the activities of prolinase and prolidase in rat salivary glands,and the effect of thyroxine administration

Summary As the salivary glands are interesting tissues to study proliferation, we studied the activities of prolinase and prolidase using Pro-Ala and Pro-Hyp as substrates, respectively, in developing rat salivary glands between day 1 and week 10 after birth. Developmental changes of prolinase activity in the submandibular and sublingual glands were similar to those in the parotid gland, which steadily increased and reached the adult level by 20–25 days after birth. However, the changes in the activity of prolidase in the submandibular and sublingual glands were different from those in the parotid gland: the activity in the parotid gland slowly increased with maturation and reached a maximum level on day 30, but the activity in the submandibular and sublingual glands continuously increased with maturation. When thyroxine was injected every two days from day 1 to day 19, both enzyme activities were induced precociously in the parotid gland but not in the submandibular and sublingual glands. On the study of regional distribution in rat tissues, the correlation coefficient between prolinase and prolidase activities was high in the peripheral but not high in the brain regions.These results indicate that the physiological roles of prolinase and prolidase are very similar but not the same.     

Immunocytochemical localization of nerve growth factor in mouse salivary glands

Summary The submandibular glands of female mice and the sublingual and parotid glands of adult male and female mice have been examined by light microscopical immunocytochemistry for nerve growth factor (NGF). In female submandibular glands, staining for NGF was observed in granular convoluted tubule and striated duct cells. Sublingual glands of the mouse contained relatively few granular cells staining for NGF compared with submandibular glands. However, such granular cells appeared to be more numerous in male sublingual glands than in female glands. The remainder of the intralobular duct cells in both male and female sublingual glands exhibited apical subluminal staining for NGF as well as light basal plasmalemmal staining. Parotid glands in both male and female mice exhibited a similar pattern of staining for NGF in striated duct cells. However, the glands did not contain granular cells nor did they exhibit any pattern of staining which reflected a sexual dimorphism. Immunodot staining of salivary gland extracts confirmed the presence of immunoreactivity for NGF in all three of the major salivary glands.     

Different localizations of 21 and 27 kDa gap-junction proteins in rat salivary glands

Antibodies against 21 and 27 kDa gap-junction proteins from rat liver were used to examine the identification and localization of gap-junction proteins in rat salivary glands. Acinar cells of the submandibular glands and parotid glands stained well for the 27 kDa gap junction protein and less intensely for the 21 kDa protein. Acinar cells of the sublingual glands were stained heavily for the 27 kDa gap junction protein and stained well for 21 kDa gap junction protein. No 27 kDa protein was observed in the ducts of the salivary glands. The 21 kDa gap-junction protein was distributed in some of the intercalated ducts in the parotid and submandibular glands. Immunoblotting of an extract of parotid glands with antibodies against 21 and 27 kDa gap-junction proteins revealed the presence of 21 and 27 kDa proteins in the parotid glands. It is concluded that the 27 kDa gap-junction protein in tistributed as a major component of the gap junctions in the acinar cells of all the salivary glands; the 21 kDa protein is localized as a minor component in the acinar cells and some portions of the intercalated ducts in the salivary glands. It is possible that these gap-junction proteins might contribute to the regulation of function of the salivary glands.     

Expression and distribution of osteopontin and matrix metalloproteinase (MMP)-3 and -7 in mouse salivary glands

We investigated the expression and distribution of osteopontin in mouse salivary glands. Western blot analysis showed intense positive bands at the predicted molecular mass (about 60 kDa) in mouse parotid and sublingual glands. However, a cross-reacted band around 30 kDa was strongly detected in submandibular glands. Indirect immunofluorescent analysis showed that osteopontin was localized at the luminal (apical) membranes of the acinar cells in parotid and sublingual glands. However, it was not detected in acinar cells of submandibular glands. No expression was found in ductal cells of any glands. We also examined the expression of matrix metalloproteinase (MMP)-3 and -7. In parotid gland, MMP-3 was observed at 57 kDa, indicating a latent form, but MMP-7 was not detected. In contrast, MMP-7 definitely was observed at 28 kDa area in submandibular gland, whereas MMP-3 was not detected. These results suggest that osteopontin localizes at luminal sites of acinar cells and may be associated with saliva secretion in mouse salivary gland. It is also suggested that osteopontin may be cleaved by MMP-7 in mouse submandibular gland.     

The sympathetic and parasympathetic nature of neuropeptide Y-immunoreactive nerve fibres in the major salivary glands of the rat

Summary The distribution and origin of neuropeptide Y in the major salivary glands of the rat was studied by indirect immunofluorescence technique. Numerous nerve fibres immunoreactive for the peptide were seen in the parotid and sublingual glands. Most of the fibres were located around blood vessels and salivary acini. In the submandibular gland the number of immunoreactive nerve fibres around the acini was lower in comparison with that in the parotid and sublingual glands. Some immunoreactive nerve fibres were also found around or along intra- and interlobular ducts in all major salivary glands.A large number of the neuropeptide-containing neuronal cell bodies and nerve fibres were detected in the sympathetic superior cervical ganglion. Sympathetic postganglionic nerve trunks of this ganglion contained numerous immunoreactive nerve fibres as well. A subpopulation of the neuronal cell bodies in the submandibular ganglion were immunoreactive to neuropeptide Y.Both uni- and bilateral superior cervical ganglionectomies caused a significant decrease in the number of immunoreactive nerve fibres around the blood vessels in all the major salivary glands. However, these denervations did not affect the density of nerve fibres around the acini and ducts. On the contrary, unilateral parasympathetic denervation by sectioning the auriculotemporal nerve reduced the fibres around the secretory acini in the parotid gland remarkably, while only a minor reduction in the density of immunoreactive fibres associated with the blood vessels of the gland was detected. Unilateral electrocoagulation of the trigeminal nerve branches caused no detectable change in the density of immunoreactive nerve fibres in any of the major salivary glands.On the basis of the present findings it is concluded that neuropeptide Y-reactive nerve fibres present in all major salivary glands around the blood vessels seem to be mainly sympathetic, whereas those around the acini and ducts seems to be of parasympathetic origin.     

Rate of protein synthesis in rat salivary gland cells after pilocarpine or feeding

In untreated, fasting animals the cells of the serous demilunes of the sublingual gland incorporate [3H]-leucine at a higher rate than any other of the 5 main cell types of the 3 major salivary glands. The acinar cells of the submandibular and the mucous cells of the sublingual gland show intermediate values, while the cells of the granular ducts of the submandibular and the acini of the parotid gland have a low rate of incorporation. In fasting animals extrusion of newly synthesized protein starts early in the cells of the serous demilunes. It starts between 4 and 7 hrs after [3H]-leucine injection in the acinar cells of the submandibular gland, while the other cell types did not lose substantial amounts of labelled (glyco)protein within 7 hrs. The secretion of protein is stimulated by the cholinergic drug pilocarpine in all but one of the 5 types of salivary gland cells studied. The acinar cells of the submandibular gland react strongly, the granular duct cells less strongly. Still less are the reactions of the acinar cells of the parotid and of the nucous cells of the sublingual gland. The cells of the serous demilunes of the latter appear to be insensible to pilocarpine. The effect of food uptake on secretion does not differ from pilocarpine stimulation, with one exception: the acinar cells of the parotid gland react more strongly on food uptake than on cholenergic stimulation.     

Comparison of membrane phospholipid and its fatty acid compositions in developing rat salivary glands

1. Membrane phospholipid and its fatty acid compositions have been analyzed in 3- and 9-week-old rat salivary glands. 2. When compared between the three major glands (parotid, submandibular, sublingual) in adult rats, phospholipid compositions were similar, but for their fatty acid, characteristic properties from each phospholipid were shown. 3. Alterations in their compositions were also observed during development of the salivary glands.     

Differential expression of proline-rich proteins in rabbit salivary glands.

Salivary glands synthesize and secrete an unusual family of proline-rich proteins (PRPs) that can be broadly divided into acidic and basic PRPs. We studied the tissue-specific expression of these proteins in rabbits, using antibodies to rabbit acidic and basic PRPs as well as antibodies and cDNA probes to human PRPs. By immunoblotting, in vitro translation, and Northern blotting, basic PRPs could be readily detected in the parotid gland but were absent in other salivary glands. In contrast, synthesis in vitro of acidic PRPs was detected in parotid, sublingual, and submandibular glands. Ultrastructural localization with immunogold showed heavy labeling with antibodies to acidic PRPs of secretory granules of parotid acinar cells and sublingual serous demilune cells. Less intense labeling occurred in the seromucous acinar cells of the submandibular gland. With antibodies to basic PRPs, the labeling of the parotid gland was similar to that observed with antibodies to acidic PRPs, but there was only weak labeling of granules of a few sublingual demilune cells, and no labeling of the submandibular gland. These results demonstrate a variable pattern of distribution of acidic and basic PRPs in rabbit salivary glands. These animals are therefore well suited for study of differential tissue expression of PRPs.     

SD大鼠和Beagle犬大唾液腺的形态学观察

目的-研究及观察SD大鼠和Beagle犬大唾液腺正常比较组织学.方法-SD大鼠和Beagle犬三对大唾液腺剖取后进行石蜡切片、HE染色和PAS染色,光学显微镜观察.结果-SD大鼠腮腺是纯浆液腺,Beagle犬腮腺属混合腺,以浆液性腺泡为主,偶见小的粘液细胞群.SD大鼠的下颌下腺属于以浆液腺泡为主的混合腺,Beagle犬的下颌下腺属于以粘液腺泡为主的混合腺.SD大鼠与Beagle犬的舌下腺均为粘液性腺泡为主的混合腺.Beagle犬的眶腺亦是以纯粘液性腺泡为主的混合腺结构.     

Characteristics of sialidase in the rat salivary glands

Using 4-methylumbelliferyl-N-acetylneuraminic acid (4MU-NeuAc) as substrate, we measured sialidase activity in the salivary glands and other organs of the rat. The pH optima of salivary gland sialidase were between 4.0 and 4.5, which were similar to those of the enzyme in the brain, liver and kidney. Among the salivary glands, the submandibular one showed the highest sialidase activity followed by the parotid and the sublingual glands. However, sialidase activity in these glands was lower when compared with the activity in the brain, liver and kidney. From the subcellular distribution study, salivary gland sialidase was found to be mainly localized in the lysosomes. The pH optima of the lysosomal sialidase of the salivary glands were between 4.0 and 4.5; and Km values for 4MU-NeuAc approximately 0.09 mmol/l. In the submandibular and parotid glands, a soluble sialidase with a different pH optimum (5.5) and Km value (0.25 mmol/l) was also detected.     

A histochemical study of catecholamines and cholinesterases in the autonomic nerves of the human minor salivary glands

Synopsis The cholinergic and adrenergic innervation of human minor sublingual buccal and labial salivary glands has been studied with histochemical techniques for localizing acetylcholinesterase and catecholamines. A rich cholinergic innervation was observed around the acini, blood vessels and some ducts of the three glands.The adrenrgic innervation, however, was virtually absent from the parenchyma although present around the blood vessels, in marked contrast to the dense parenchymal adrenergic innervation observed in the human parotid and submandibular glands. These results suggest that the autonomic nervous mechanism which regulates salivary secretion is more elaborate in the major than in the minor salivary glands.     

Comparative developmental analysis of the parotid, submandibular and sublingual glands in the neonatal rat.

Analysis of the soluble protein fractions from the rat parotid, submandibular and sublingual glands by polyacrylamide-gel electrophoresis reveals similarities in overall patterns of protein synthesis at birth. Tissue-specific changes in protein and glycoprotein synthesis occur shortly after birth and again at the time of weaning, 21--28 days later. Incorporation of [3H]thymidine into DNA was at its highest after birth and gradually decreased in both the parotid and submandibular gland, whereas [3H]thymidine incorporation in the sublingual gland was low throughout the time of neonatal development. [14C]Leucine incorporation into total protein increased in all glands with age after birth, showing an accelerated rate 21--28 days later. Trichloroacetic acid/phosphotungstic acid-precipitable [3H]fucose in glycoproteins declined over the time of neonatal development in the parotid and submandibular gland, but its incorporation remained higher in the sublingual gland. alpha-Amylase (EC 3.2.1.1) in the salivary glands increased at the time of weaning, as judged by detectability in sodium dodecyl sulphate/polyacrylamide gels and by immune precipitation. Two membrane-bound enzymes, UDP-galactose:2-acetamido-2-deoxy-D-glucosamine 4 beta-galactosyltransferase (EC 2.4.1.22) and UDP-galactose:2-acetamido-2-deoxy-D-galactosaminyl-protein 3 beta-galactosyltransferase (no EC number), undergo tissue-specific change rather than changes induced by physiological stimulation of the salivary glands.