Constituents Of Saliva Research Articles

Alterations in Whole Saliva Constituents in Patients with Diabetes Mellitus and Periodontal Disease

The oral cavity holds great many secrets which are reflected purely in its appearance and function. Hence, very aptly the oral cavity is said to be the mirror of systemic diseases as many a systemic diseases can be identified on the basis of their oral manifestations alone.2 Diabetes mellitus is one such complex multifactorial genetic disorder of unknown etiology characterized by increased insulin secretion and decreased salivation.3 In addition to these the most common oral manifestation is the presence of periodontal disease, whose presence and severity can often lead the oral physician to suspect an underlying diabetes mellitus. This association of diabetes with periodontitis is attributed to the alterations in the permeability of the basement membrane, improper neutrophil chemotaxis, collagen synthesis, genetic predisposition and an increased susceptibility to periodontal pathogens.2 Salivary glands are important glands of the digestive system and serve functions which influence oral health in general. The salivary secretions are also very convenient for extirpation and collection. With an increase in investigator interest it is becoming apparent that many systemic diseases affect salivary gland function and/or composition potentiating its probable role as an indicator of the disease process.2 Also with the advent in sensitive immunochemical assays continuing, the compositional profile of human salivary secretions is expanding considerably, thus, establishing a range of normal values for a variety of intrinsic and extrinsic salivary components representing a stepping stone to use saliva as a diagnostic tool to assess oral health status.

Optimization of a polymerase chain reaction based assay for the detection of malaria in human saliva samples

Background Malaria is responsible for more than 1 million deaths per year; most of the victims are young African children [1]. Recent studies have found that Plasmodium falciparum DNA is detectable in human saliva as in human blood [2]. However the nature of the source of the saliva fraction that serve as source of this DNA still unclear. Thus this study sought to establish the constituents of human saliva that harbours parasite the DNA in malaria infected subjects.

The potential of liposomes as dental drug delivery systems

The potential of liposomes as a drug delivery system for use in the oral cavity has been investigated. Specifically targeting for the teeth, the in vitro adsorption of charged liposomal formulations to hydroxyapatite (HA), a common model substance for the dental enamel, has been conducted. The experiments were performed in human parotid saliva to simulate oral-like conditions. It was observed, however, that precipitation occurred in tubes containing DPPC/DPTAP or DPPC/DPPG-liposomes in parotid saliva with no HA present, indicating that constituents of parotid saliva reacted with the liposomes. The aggregation reactions of liposome–parotid saliva mixtures were examined by turbidimetry and by atomic force microscopy. Negatively charged DPPC/DPPS and DPPC/PI-liposomes were additionally included in these experiments. The initial turbidity of positive DPPC/DPTAP-liposomes in parotid saliva was very high, but decreased markedly after 30 min. AFM images showed large aggregates of micelle-like globules known to be present in saliva. The turbidity of the various negatively charged liposome and parotid saliva mixtures stayed relatively constant throughout the measuring time; however, their initial turbidities were different; mixtures with DPPC/DPPG-liposomes were the most turbid and DPPC/DPPA-liposomes the least. Pyrophosphate (PP) was added to the various liposome–parotid saliva mixtures to examine the effect of Ca 2+ on the interactions. The effect of PP treatment of the negatively charged liposome–parotid saliva mixtures was most pronounced with DPPC/DPPG-liposome mixtures where it caused a sudden drop in turbidity. For positive DPPC/DPTAP liposome and parotid saliva mixtures, the effect of PP was minimal. These experiments showed that saliva constituents may interact with liposomes. An appropriate liposomal drug delivery system intended for use in the oral cavity seems to be dependent on the liposomal formulation. Based on the present results, negatively charged DPPC/DPPA-liposomes seem to be most suitable for use in the oral cavity as they were found to be the least reactive with the components of parotid saliva.

Large-scale phosphoproteome of human whole saliva using disulfide–thiol interchange covalent chromatography and mass spectrometry

To date, only a handful of phosphoproteins with important biological functions have been identified and characterized in oral fluids, and these include some of the abundant protein constituents of saliva. Whole saliva (WS) samples were trypsin digested, followed by chemical derivatization using dithiothreitol (DTT) of the phospho-serine/threonine-containing peptides. The DTT–phosphopeptides were enriched by covalent disulfide–thiol interchange chromatography and analysis by nanoflow liquid chromatography and electrospray ionization tandem mass spectrometry (LC–ESI–MS/MS). The specificity of DTT chemical derivatization was evaluated separately under different base-catalyzed conditions with NaOH and Ba(OH) 2, blocking cysteine residues by iodoacetamide and enzymatic O-deglycosylation prior to DTT reaction. Further analysis of WS samples that were subjected to either of these conditions provided supporting evidence for phosphoprotein identifications. The combined chemical strategies and mass spectrometric analyses identified 65 phosphoproteins in WS; of these, 28 were based on two or more peptide identification criteria with high confidence and 37 were based on a single phosphopeptide identification. Most of the identified proteins (∼80%) were previously unknown phosphoprotein components. This study represents the first large-scale documentation of phosphoproteins of WS. The origins and identity of WS phosphoproteome suggest significant implications for both basic science and the development of novel biomarkers/diagnostic tools for systemic and oral disease states.

Medicinal leech therapy (Hirudotherapy) : A brief overview

Hirudotherapy is a treatment using medicinal leeches. Hirudo medicinali, have been used to treat patients for centuries. In the past, leeches have proved to be an effective treatment for a number of conditions including battle wound treatment. Currently leeches may be used to assist in the treatment of abscesses, arthritis, glaucoma, myasthenia gravis, thrombosis and some venous disorders. Medical leeches may also be used in plastic surgery and in some blood circulatory problems. During feeding, leeches secrete a complex mixture of different biologically and pharmacologically active substances into the wound. Hirudin is the prominent constituent of leech saliva. It is sometimes used to describe all the active constituents in the leech saliva. This paper outlines the potential use of leech therapy in current medical care in India.

Evidence for Airway Acidity and Oxidative Stress in Exhaled Breath Condensates from Grain Workers

In their article, Dr. Do and colleagues described exhaled breath condensate (EBC) studies that they interpret to indicate airway acidity and oxidative stress (8-isoprostane) in grain workers (1). Unfortunately, neither of these conclusions can be drawn on the basis of the data they have collected. With regard to pH, the species NH4 1 and HCO3 2 represent approximately 90% of the acids and bases found in most samples of EBC (2). Generation of approximately 90% of the NH4 1 is in the mouth rather than the airways, much of it from bacterial degradation of urea (3). Low concentrations of volatile organic acids (e.g., acetic acid) may be found in EBC, but these may also represent oral contamination. Abnormal EBC pH probably reflects oral rather than airway metabolism (3), and the pH and constituents of saliva should have been measured. Furthermore, the investigators did not measure amylase concentrations in the EBC to detect direct salivary contamination, which is more likely because the condenser they used is close to the mouth during collection. Filtering the EBC is not well justified in the article and had no effect. Furthermore, exposure of the samples to argon leaves behind much of the CO2/HCO3 2 and may cause loss of other volatile acids and bases. Interpretation of EBC pH is problematical because the buffering capacity of the EBC was not measured. Condensates should not be used to collect volatile constituents such as NH3 since recovery of these solutes in the aqueous phase can be influenced by local pH, temperature, airflow, and turbulence in airways and condensers. With regard to isoprostane, EBC concentrations of isoprostane cannot be reliably used to estimate either concentrations or changes in concentrations of isoprostane in the airways unless a dilutional indicator is also measured (e.g., conductivity of lyophilized samples, which is readily measured with simple equipment) (4). Increased 8-isoprostane concentrations may reflect the production of more respiratory droplets in the airways rather than increased concentrations in the airway fluid. EBC concentrations of nonvolatiles are approximately 1% those in bronchoalveolar lavage (BAL) and 0.01% those in respiratory fluids. It is therefore puzzling that EBC 8-isoprostane levels in the normals of Do and coworkers (z10 pg/mL) are nearly the same as those reported in BAL by others (5). The EBC approach holds the promise that airway constituents may be measured noninvasively, but oral contamination with volatile solutes and extreme and variable dilution by water vapor from the airways must be experimentally addressed in all studies of this sort.

Gingival crevicular fluid in the diagnosis of periodontal and systemic diseases

Gingival crevicular fluid (GCF) can be found in the physiologic space (gingival sulcus), as well as in the pathological space (gingival pocket or periodontal pocket) between the gums and teeth. In the first case it is a transudate, in the second an exudate. The constituents of GCF originate from serum, gingival tissues, and from both bacterial and host response cells present in the aforementioned spaces and the surrounding tissues. The collection and analysis of GCF are the noninvasive methods for the evaluation of host response in periodontal disease. These analyses mainly focus on inflammatory markers, such as prostaglandin E2, neutrophil elastase and beta-glucuronidase, and on the marker of cellular necrosis-aspartat aminotransferase. Further, the analysis of inflammatory markers in the GCF may assist in defining how certain systemic diseases (e.g., diabetes mellitus) can modify periodontal disease, and how peridontal disease can influence certain systemic disorders (atherosclerosis, preterm delivery, diabetes mellitus and some chronic respiratory diseases). Major factors which influence the results obtained from the analyses of GCF are not only the methods of these analyses, but the method of GCF collection as well. As saliva collection is less technique-sensitive than GCF collection, some constituents of saliva which originate from the GCF can be analysed as more amenable to chairside utilization.

Analysis of the Human Salivary Peptidome by Differential Peptide Display and LC-MS/MS Overview Sequencing

In recent years interest in the characterization of the human salivary proteome has increased in order to explore its diagnostic potential. Major constituents of human saliva are highly polymorphic proteins that may have biological roles in oral lubrication and protection, e.g. proline-rich proteins (PRPs), statherins, histatins and cystatins. Interestingly, many of theses proteins are rapidly degraded in the oral cavity by host- and bacteria- or viral-derived proteases. Thus, compre- hensive analysis of peptides up to 15 kDa (peptidomics) of whole saliva may yield basic information on proteolytic pat- terns. By employing a LC-ESI-MS/MS approach a total of 107 native peptides from 17 distinct protein precursors was identified from whole saliva. Subsequently the catalog of peptides was used to analyze inter-individual differences in sa- liva samples from four donors by differential peptide display technology. Genetic polymorphisms were found in peptides from the PRB4M_HUMAN and PROL4_HUMAN precursors. Analysis of the proposed N- and C-termini of the peptides revealed frequent cleavage after Lys or Arg which is characteristic for salivary kallikrein enzymes. Furthermore, we high- light the cleavage motif Gln/Gly in the PRP-C precursor, which suggests a new proteolytic pattern in saliva.

Application of ion chromatography for the determination of inorganic ions, especially thiocyanates in human saliva samples as biomarkers of environmental tobacco smoke exposure

Environmental tobacco smoke is a major factor influencing the indoor air quality. Various toxic compounds emitted during tobacco smoking into the environment have a significant influence on the chemical composition of human biological fluids. The thiocyanate concentration in saliva is a biochemical measure, frequently used as an objective indicator of tobacco consumption. The goal of this study was to find significant relationships between salivary thiocyanates and other inorganic ions, which are constituents of natural saliva (Na +, K +, Mg 2+, Ca 2+, Cl −, PO 4 3−) and to present the effectiveness of the proposed sample preparation procedure combined with ion chromatography technique for the determination of inorganic ions in human saliva samples collected from passive, moderate and heavy smokers.

Phlebotomine salivas inhibit immune inflammation-induced neutrophil migration via an autocrine DC-derived PGE2/IL-10 sequential pathway

In the present study, we investigated whether saliva from Phlebotomus papatasi and Phlebotomus duboscqi inhibited antigen-induced neutrophil migration and the mechanisms involved in these effects. The pretreatment of immunized mice with salivary gland extracts (SGE) of both phlebotomines inhibited OVA challenge-induced neutrophil migration and release of the neutrophil chemotactic mediators, MIP-1alpha, TNF-alpha, and leukotriene B4 (LTB4). Furthermore, SGE treatment enhanced the production of anti-inflammatory mediators, IL-10 and PGE2. SGE treatments failed to inhibit neutrophil migration and MIP-1alpha and LTB4 production in IL-10-/- mice, also failing in mice treated with nonselective (indomethacin) or selective (rofecoxibe) cyclooxygenase (COX) inhibitors. COX inhibition resulted in diminished SGE-induced IL-10 production, and PGE2 release triggered by SGE remained increased in IL-10-/- mice, suggesting that prostanoids are acting through an IL-10-dependent mechanism. SGE treatments in vivo reduced the OVA-induced lymphoproliferation of spleen-derived cells. Further, the in vitro incubation of bone marrow-derived dendritic cells (DC) with SGE inhibited the proliferation of CD4+T cells from OVA-immunized mice, which was reversed by indomethacin and anti-IL-10 antibody treatments. Supporting these results, SGE induced the production of PGE2 and IL-10 by DC, which were blocked by COX inhibition. These effects were associated with the reduction of DC-membrane expression of MHC-II and CD86 by SGE treatment. Altogether, the results showed that Phlebotomine saliva inhibits immune inflammation-induced neutrophil migration by an autocrine DC sequential production of PGE2/IL-10, suggesting that the saliva constituents might be promising therapeutic molecules to target immune inflammatory diseases.

The Effect of Mucine, IgA, Urea, and Lysozyme on the Corrosion Behavior of Various Non-precious Dental Alloys and Pure Titanium in Artificial Saliva

The corrosion of dental alloys has biological, functional, and aesthetic consequences. Various studies have shown that protein solutions can inhibit the corrosion of alloys. This study is planned to determine the relationship of organic constituents of saliva and the corrosion of dental alloys. The organic constituents are IgA, mucine, urea, and lysozyme which are encountered in the highest amounts in saliva and the dental materials are titanium (Ti), Co-Cr-Mo and Ni-Cr-Mo alloys, and dental amalgam, the most often used metallic components in dentistry. In particular, the interactions between the commonest salivary proteins, IgA, mucine, urea and lysozyme, and Ti, Co-Cr-Mo, Ni-Cr-Mo and dental amalgam were investigated. Each alloy was evaluated by cyclic polarization in each medium. The general anodic and cathodic behavior during forward and reverse cycles, the corrosion and passivation current densities (muA/cm2 ), and the corrosion and the pitting potentials (mV) were determined. The results have shown that Ni-Cr-Mo and dental amalgam alloys are highly susceptible to corrosion in all the investigated media. The Co-Cr-Mo alloy has shown high passive current densities in the solution of mucine and lysozyme in artificial saliva. Titanium instead, has shown a high resistance to corrosion and a stable passive behavior in all media, especially in a solution of mucine and IgA in synthetic saliva. Mucine and IgA, as well as urea and lysozyme, appeared to enhance the formation of a passive film layer on the Ti metal surface, thus inhibiting the corrosion. Based on the study findings, and especially considering the problem of nickel allergy and toxicity of mercury released from dental amalgam, the use of Co-Cr-Mo alloys and Ti to Ni-Cr-Mo alloys is recommended and alternatives to dental amalgam should be sought for patients with impaired salivary flow.

Molecular sabotage of plant defense by aphid saliva.

Aphids, which constitute one of the most important groups of agricultural pests, ingest nutrients from sieve tubes, the photoassimilate transport conduits in plants. Aphids are able to successfully puncture sieve tubes with their piercing mouthparts (stylets) and ingest phloem sap without eliciting the sieve tubes' normal occlusion response to injury. Occlusion mechanisms are calcium-triggered and may be prevented by chemical constituents in aphid saliva injected into sieve tubes before and during feeding. We recorded aphid feeding behavior with the electrical penetration graph (EPG) technique and then experimentally induced sieve tube plugging. Initiation of sieve tube occlusion caused a change in aphid behavior from phloem sap ingestion to secretion of watery saliva. Direct proof of "unplugging" properties of aphid saliva was provided by the effect of aphid saliva on forisomes. Forisomes are proteinaceous inclusions in sieve tubes of legumes that show calcium-regulated changes in conformation between a contracted state (below calcium threshold) that does not occlude the sieve tubes and a dispersed state (above calcium threshold) that occludes the sieve tubes. We demonstrated in vitro that aphid saliva induces dispersed forisomes to revert back to the nonplugging contracted state. Labeling Western-blotted saliva proteins with 45Ca2+ or ruthenium red inferred the presence of calcium-binding domains. These results demonstrate that aphid saliva has the ability to prevent sieve tube plugging by molecular interactions between salivary proteins and calcium. This provides aphids with access to a continuous flow of phloem sap and is a critical adaptation instrumental in the evolutionary success of aphids.

Overexpression and characterization of two human salivary proline rich proteins

Proline rich proteins (PRP) are among major human saliva constituents and are known to interact with wine tannins that are involved in astringency. To characterize these interactions, a human salivary proline rich pro-protein, PRB4S, was overexpressed in Pichia pastoris. Six recombinant proteins resulting from maturation in bioreactor were detected by SDS–PAGE analysis between 15 and 45 kDa (apparent molecular weight). Two of them, the 45 and the 15 kDa ones, were isolated from culture supernatant by adsorption and permeation chromatography. They were characterized by N-terminal sequencing and MALDI-TOF analysis after trypsic digestion. The 45 kDa protein is glycosylated while the 15 kDa one was obtained after a furin-like proteolysis. Both of them are similar to human whole saliva PRP resulting from proteolysis of PRB4S pro-protein in Golgi network and known as II-1 and IB-5. Because of their sensitivity to proteolysis or their unusual mobility on SDS–PAGE gel, these recombinant proteins seem to be intrinsically unstructured proteins.

Glutamate concentration in whole saliva and taste responses to monosodium glutamate in humans

It is universally accepted that saliva plays an important role in taste sensations. However, interactions between constituents of whole saliva and the five basic taste modalities are still poorly understood. The aim of the present study was to evaluate possible relationship between endogenous glutamate (Glu) levels in whole saliva and taste responses to a prototypic umami substance, monosodium glutamate (MSG; 0.03–10.0%). Rated intensity and pleasantness of MSG taste was studied in healthy volunteers divided into a high glutamate (HG) in saliva (HG; n = 19) and low glutamate in saliva (LG; n = 18) group based on the median split level of salivary Glu. The HG and LG group did not differ in terms of electrogustometric thresholds, rated intensity of the MSG samples and pleasantness of distilled water and the lower MSG concentrations (0.03–1.0%). Perceived intensity of water taste was significantly ( P

Determination of lead in human saliva by combined cloud point extraction–capillary zone electrophoresis with indirect UV detection

A micelle-mediated phase separation without added chelating agents to preconcentrate trace levels of lead in human saliva as a prior step to its determination by capillary electrophoresis has been developed. The enrichment step is based on the cloud point extraction of lead with the non-ionic surfactant PONPE 7.5 in the absence of chelating agent. The surfactant-rich phase was diluted with acetonitrile and the resultant solution was injected directly into the CE instrument. Factors affecting the combined methodology such as surfactant-rich phase diluting agent, buffer pH and concentration, applied voltage, sample preparation and presence of additives were studied in detail. A BGE of 20 mM imidazole containing 30% acetonitrile, pH 6.20 was found to be optimal for the separation of lead from other saliva constituents. Indirect detection was performed at 205 nm. The detection limit value of lead for the preconcentration of 8 ml of saliva was 11.4 μg l −1. The calibration graph using the preconcentration system was linear with a correlation coefficient of 0.997 at levels near the detection limits up to at least 400 μg l −1. The reproducibility (R.S.D.) on the basis of migration time and peak area were better than 0.68 and 3.6%, respectively. The method was successfully applied to the determination of lead in human saliva.

Relationship between nitrate/nitrite concentration in saliva and oral candidosis

It has previously been claimed that nitrite protects against infections caused by Candida albicans . Nitrate and nitrite are natural constituents of saliva. The aim of the present study was to investigate if patients with oral candidosis have amounts of nitrate and nitrite in their saliva that differ from those of control persons. The study comprised 17 women and 7 men who were allotted to two experimental groups with yeast infection and two control groups with no clinical signs of candidosis. Within both the experimental and the control group one group consisted of dentates, and one group was made up of denture-wearers. In total there were four groups with six patients in each. All participants were examined for oral yeasts by cultivation on a selective medium (CHROMagar Candida) and Gram stain. The isolates were identified after automated reading of ID32C-inoculated test kits (bioMe´rieux). Four of the participants suffered or had previously suffered from oral cancer. In denture wearers there was no difference in the amount of nitrate and nitrite in patients with yeast infections compared to controls. However, in dentate patients there was a significantly higher amount of both nitrate and nitrite in the saliva compared with controls. Therefore, high levels of nitrate and nitrite may not consistently protect against infections with C. albicans . Key words: nitrate, nitrite, saliva, yeasts, infection

Salivary and serum β2-microglobulin and gamma-glutamyl-transferase in patients with primary Sjögren syndrome and Sjögren syndrome secondary to systemic lupus erythematosus

Background: Sialochemistry has been proposed as a simple and useful tool for the diagnosis of Sjögren syndrome (SS). Although many changes have been detected in several constituents of saliva from patients with SS, none are individually sensitive or specific enough for diagnosing SS. The aim of this study was to assess the value of the combined determination of β2-microglobulin (β2m) and gamma-glutamyl-transferase (GGT) activity in serum and saliva as a diagnostic instrument for differentiating primary and secondary [to systemic lupus erythematosus (SLE)] SS patients from normal subjects. Methods: Nineteen primary SS (pSS) patients, 15 patients with SS secondary to SLE, and 25 SLE patients without SS were studied. Thirty healthy subjects were included in the study as control group. Results: By means of a mathematical model, (a) 84.1%, (b) 85.7%, and (c) 87.0% of patients were correctly classified as SS or normal when (a) salivary β2m and GGT values, (b) serum β2m and salivary GGT values, and (c) salivary β2m and GGT along with serum β2m values, respectively, were considered. To differentiate between pSS and sSS by means of the mathematical model, the combination of serum β2m and salivary GGT values achieved that 81.8% of the patients were correctly classified. Conclusion: Since sialochemistry is an easy, safe and reliable test, the combined determination of β2m and GGT in saliva and serum was useful for differentiating SS patients from normal subjects, but not excessively good for differentiating pSS from sSS patients.

The role of salivary function in modulating chemotherapy-induced oropharyngeal mucositis: a review of the literature.

Oropharyngeal mucositis is a common and significant complication of cancer chemotherapy and limits the delivery of chemotherapy, affects the quality of life, and increases the cost of care. Oral mucositis caused by cancer chemotherapy is associated with specific agents, but the origin of oral mucositis is poorly understood. These drugs may have direct toxic effects on the rapidly dividing cells of the oral mucosa and on cellular elements of the connective tissue. Microbial flora may play a role in the development of ulcerative mucositis. Chemotherapy may be directly toxic and affect the mucosa by systemic circulation and may be related to secretion of some chemotherapeutic drugs in the saliva, resulting in topical exposure to the oral environment. Other potential mechanisms include reduced saliva volume and change in saliva constituents that may affect epithelial maintenance and repair, the physiology of the oral microflora, and the interaction between the oral flora and the epithelium. Improved understanding of the mechanisms whereby specific chemotherapeutic agents cause mucositis may lead to management approaches that will reduce the incidence and severity of mucositis, improving quality of life and ensuring delivery of the necessary chemotherapy to improve cancer cure rates.

Salivary mucin: a factor in the lower prevalence of gastroesophageal reflux disease in African-Americans?

OBJECTIVES: Organic and inorganic constituents of saliva have been implicated as protective components in the esophagus, and deficiencies in one or more of these factors in different races may be an important element in the prevalence of gastroesophageal reflux disease (GERD). To determine whether there are differences in the concentration of salivary mucins between different racial groups, we measured the concentration of mucous glycoprotein MG1 and mucous glycoprotein MG2 in whole saliva of African-Americans and Caucasians. METHODS: Whole saliva was collected from 19 African-American (four male, 15 female; mean age 34 yr, range 19–53 yr, ) and 25 Caucasian (11 male, 14 female; mean age 31 yr, range 20–51 yr, ) volunteers under masticatory stimulation (1 g Parafilm, 60 strokes/min) between 11:00 AM and 12:00 noon. Total salivary carbohydrate was measured with a periodic acid-Schiff assay and total protein by absorbance at 215 nm. Immunological reagents were employed to quantify MG2 in a combined enzyme-linked immunosorbent assay/enzyme linked lectin assay (ELISA/ELLA) and to quantify MG1 in a capture ELISA. RESULTS: The total carbohydrate, protein, MG1 and MG2 values were 24.4 ± 11.9, 243.5 ± 62.7, 21.8 ± 13.4, and 11.6 ± 9.5 mg% for African-Americans, and the corresponding values were 23.3 ± 9.3, 221.7 ± 39.7, 25.7 ± 16.2, and 10.9 ± 8.7 mg% for Caucasians. There was no statistical difference for any of the parameters measured between the two groups. Furthermore, it was shown that no correlation existed between salivary flow rate and the concentration of carbohydrate, protein, or salivary mucins in African-Americans and in Caucasians. These results show that flow rate did not influence the measured values for salivary parameters in the two groups. CONCLUSIONS: No differences were found in the concentration of salivary mucins MG1 and MG2 in whole saliva of African-Americans and Caucasians, and it seems unlikely that variations in mucin levels influence the prevalence of GERD in these groups.

Secretion of TFF-peptides by human salivary glands.

TFF-peptides (formerly P-domain peptides, trefoil factors) are typical secretory products of mucin-producing cells and seem to influence the rheological properties of mucous gels. Here, localization studies of TFF-peptides in human salivary glands are presented. Expression studies (polymerase chain reaction) revealed mainly TFF3 transcripts in submandibular and sublingual glands and trace amounts in parotid glands. Only low levels of expression of TFF1 could be monitored in submandibular and sublingual glands, and TFF2 transcripts were hardly detectable in all three major salivary glands. This result was partly confirmed by Western blot analysis, which only detected TFF3 in submandibular glands, but not in sublingual and parotid glands. TFF3 was also shown to be a constituent of human saliva. Immunofluorescence localized TFF3 solely in the secretory granules of serous cells of submandibular glands but not in mucous cells. This localization is remarkably similar to that of the unique low-molecular-weight mucin MUC7, which interacts with a number of oral microorganisms.