RESUMO
Saliva exerts multiple functions in relation to the initial digestive processes taking place in the upper parts of the gastrointestinal tract. Ingestion of food and beverages, in turn, is a strong stimulus for secretion of saliva with a differential composition depending on the neuronal stimulation pattern. This review paper provides insight into the mechanisms by which saliva acts in relation to taste, mastication, bolus formation, enzymatic digestion and swallowing. Also, the protective functions of saliva including maintenance of dental and mucosal integrity will be discussed as they indirectly influence the digestive process. The final part of this study focuses on the implications of xerostomia and salivary gland dysfunction on gastrointestinal functions.
Assuntos
Saliva/fisiologia , Glândulas Salivares/fisiologia , Salivação , Sistema Nervoso Autônomo/fisiologia , Deglutição , Digestão , Mucosa Esofágica/fisiologia , Humanos , Mastigação , Mucosa Bucal/fisiologia , Saúde Bucal , Sialorreia/complicações , Sialorreia/fisiopatologia , Paladar , Xerostomia/complicações , Xerostomia/fisiopatologiaRESUMO
Saliva is a complex fluid produced by 3 pairs of major salivary glands and by hundreds of minor salivary glands. It comprises a large variety of constituents and physicochemical properties, which are important for the maintenance of oral health. Saliva not only protects the teeth and the oropharyngeal mucosa, it also facilitates articulation of speech, and is imperative for mastication and swallowing. Furthermore, saliva plays an important role in maintaining a balanced microbiota. Thus, the multiple functions provided by saliva are essential for proper protection and functioning of the body as a whole and for the general health. A large number of diseases and medications can affect salivary secretion through different mechanisms, leading to salivary gland dysfunction and associated oral problems, including xerostomia, dental caries and fungal infections. The first part of this review article provides an updated insight into our understanding of salivary gland structure, the neural regulation of salivary gland secretion, the mechanisms underlying the formation of saliva, the various functions of saliva and factors that influence salivary secretion under normal physiological conditions. The second part focuses on how various diseases and medical treatment including commonly prescribed medications and cancer therapies can affect salivary gland structure and function. We also provide a brief insight into how to diagnose salivary gland dysfunction.
Assuntos
Mastigação/fisiologia , Saúde Bucal , Saliva/fisiologia , Glândulas Salivares/fisiologia , Salivação/fisiologia , Xerostomia/fisiopatologia , Humanos , Saliva/química , Glândulas Salivares/anatomia & histologiaRESUMO
OBJECTIVES: To describe parotid gland (PG) saliva organic and inorganic composition and flow rate changes, after curative intensity-modulated radiotherapy (IMRT) for head and neck cancer (HNC), and analyse the relationship between PG saliva analytes and xerostomia measures. METHODS AND MATERIALS: Twenty-six patients recruited to five prospective phase 2 or 3 trials which assessed toxicity and efficacy of IMRT by HNC subsite, provided longitudinal PG saliva. Salivary flow rate, and subjective and objective xerostomia measures were prospectively collected and saliva tested for inorganic and organic analytes. Statistical comparisons of longitudinal analyte changes and analysis for a relationship between dichotomized xerostomia score and saliva analytes were performed. RESULTS: One hundred and forty-two PG saliva samples from 26 patients were analysed. At 3-6 months after IMRT, stimulated and unstimulated saliva showed significantly decreased flow rate, total protein (TP) secretion rate, phosphate concentration and increased lactoferrin (LF) concentration. Stimulated saliva alone had elevated LF secretion rate and beta-2-microglobulin (B2 M) concentration with decreased calcium (Ca2+ ) and magnesium (Mg2+ ) concentrations and Ca2+ secretion rate. At >12 months, under stimulated and unstimulated conditions, increased LF concentration and decreased Mg2+ and phosphate concentration persisted and, in stimulated saliva, there was decreased potassium (K+ ) and Mg2+ concentration. Unstimulated TP secretion rate was lower in the presence of high-grade xerostomia. Otherwise, no relationship between xerostomia grade and PG salivary flow rate, TP and Ca2+ secretion rate was found. CONCLUSION: Fewer significant differences in PG saliva analytes >12 months after IMRT indicate good functional recovery. Residual xerostomia after IMRT will only be further reduced by addressing the sparing of subsites of the PG or other salivary gland tissues, in addition to the PG.
Assuntos
Neoplasias de Cabeça e Pescoço/radioterapia , Tratamentos com Preservação do Órgão , Glândula Parótida/efeitos da radiação , Radioterapia de Intensidade Modulada/métodos , Saliva/química , Saliva/efeitos da radiação , Adulto , Idoso , Ensaios Clínicos Fase II como Assunto , Ensaios Clínicos Fase III como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Órgãos em Risco , Doses de Radiação , Radioterapia de Intensidade Modulada/efeitos adversos , Saliva/metabolismo , Xerostomia/etiologiaRESUMO
OBJECTIVES: To study which salivary proteins form the protective bound mucosal pellicle and to determine the role of transglutaminase in pellicle development. MATERIALS AND METHODS: Oral epithelial cells were collected and underwent washes of different strengths, followed by homogenisation. SDS-PAGE, western blotting, IgA ELISAs and amylase activity assays were completed on cell homogenates and compared to saliva samples to confirm which salivary proteins were bound to cell surfaces. RESULTS: Salivary mucins, MUC5B and MUC7, were strongly retained on the oral epithelial cell surface. Other bound proteins including cystatin S, carbonic anhydrase VI, secretory component and IgA could be washed off. IgA was present in concentrated levels in the bound mucosal pellicle compared to amounts in saliva. Amylase, one of the most abundant proteins present in saliva, showed minimal levels of binding. Transglutaminase 3 presence was confirmed, but proteins that it catalyses cross-links between, statherin and proline-rich proteins, showed minimal presence. CONCLUSION: Some protective salivary proteins including mucins and IgA become concentrated on oral surfaces in the bound mucosal pellicle, through specific interactions. Concentration of mucins would contribute to lubrication to prevent abrasion damage to soft tissues, whilst increased IgA could create an 'immune reservoir' against mucosal infection.
Assuntos
Película Dentária/química , Mucosa Bucal/química , Mucina-5B/análise , Mucinas/análise , Proteínas e Peptídeos Salivares/análise , Parede Celular , HumanosRESUMO
The oral microbiome is one of the most stable ecosystems in the body and yet the reasons for this are still unclear. As well as being stable, it is also highly diverse which can be ascribed to the variety of niches available in the mouth. Previous studies have focused on the microflora in disease-either caries or periodontitis-and only recently have they considered factors that maintain the normal microflora. This has led to the perception that the microflora proliferate in nutrient-rich periods during oral processing of foods and drinks and starves in between times. In this review, evidence is presented which shows that the normal flora are maintained on a diet of salivary factors including urea, lactate, and salivary protein degradation. These factors are actively secreted by salivary glands which suggests these factors are important in maintaining normal commensals in the mouth. In addition, the immobilization of SIgA in the mucosal pellicle indicates a mechanism to retain certain bacteria that does not rely on the bacterial-centric mechanisms such as adhesins. By examining the salivary metabolome, it is clear that protein degradation is a key nutrient and the availability of free amino acids increases resistance to environmental stresses.
Assuntos
Imunoglobulina A Secretora , Microbiota , Película Dentária , Boca , Saliva , Proteínas e Peptídeos SalivaresRESUMO
Metabolomics has been identified as a means of functionally assessing the net biological activity of a particular microbial community. Considering the oral microbiome, such an approach remains largely underused. While the current knowledge of the oral microbiome is constantly expanding, there are several deficits in knowledge particularly relating to their interactions with their host. This work uses nuclear magnetic resonance spectroscopy to investigate metabolic differences between oral microbial metabolism of endogenous (i.e., salivary protein) and exogenous (i.e., dietary carbohydrates) substrates. It also investigated whether microbial generation of different metabolites may be associated with host taste perception. This work found that in the absence of exogenous substrate, oral bacteria readily catabolize salivary protein and generate metabolic profiles similar to those seen in vivo. Important metabolites such as acetate, butyrate, and propionate are generated at relatively high concentrations. Higher concentrations of metabolites were generated by tongue biofilm compared to planktonic salivary bacteria. Thus, as has been postulated, metabolite production in proximity to taste receptors could reach relatively high concentrations. In the presence of 0.25 M exogenous sucrose, increased catabolism was observed with increased concentrations of a range of metabolites relating to glycolysis (lactate, pyruvate, succinate). Additional pyruvate-derived molecules such as acetoin and alanine were also increased. Furthermore, there was evidence that individual taste sensitivity to sucrose was related to differences in the metabolic fate of sucrose in the mouth. High-sensitivity perceivers appeared more inclined toward continual citric acid cycle activity postsucrose, whereas low-sensitivity perceivers had a more efficient conversion of pyruvate to lactate. This work collectively indicates that the oral microbiome exists in a complex balance with the host, with fluctuating metabolic activity depending on nutrient availability. There is preliminary evidence of an association between host behavior (sweet taste perception) and oral catabolism of sugar.
Assuntos
Microbiota , Percepção Gustatória , Humanos , Boca , PaladarRESUMO
One of the most accepted mechanisms of astringency consists of the interaction between polyphenols and some specific salivary proteins. This work aims to obtain further insights into the mechanisms leading to a modulation of astringency elicited by polyphenols. The effect of the presence of different chemical species (present in food and beverages as food additives) on the polyphenol-protein interaction has been evaluated by means of techniques such as sodium dodecyl sulfate polyacrylamide gel electrophoresis and cell cultures using a cell-based model of the oral epithelium. Results obtained showed that several chemicals, particularly sodium carbonate, seem to inhibit polyphenol binding to salivary proteins and to oral epithelium. These results point out that polyphenol-saliva protein interactions can be affected by some food additives, which can help to better understand changes in astringency perception.
Assuntos
Aromatizantes/química , Polifenóis/química , Proteínas e Peptídeos Salivares/química , Vinho/análise , Adulto , Feminino , Aromatizantes/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Polifenóis/metabolismo , Saliva/química , Saliva/metabolismo , Proteínas e Peptídeos Salivares/metabolismo , Taninos/química , Taninos/metabolismo , PaladarRESUMO
Adult rat submandibular glands have a rich autonomic innervation, with parasympathetic and sympathetic nerves working in synergy rather than antagonistically. Ligation of the secretory duct rapidly causes atrophy and the loss of most acini, which are the main target cell for parasympathetic nerves. Following deligation, there is a recovery of gland structure and function, as assessed by autonomimetic stimulation. This study examines whether the parasympathetic nerves reattach to new target cells to form functional neuro-effector junctions. Under recovery anaesthesia, the submandibular duct of adult male rats was ligated via an intra-oral approach to avoid damaging the chorda-lingual nerve. Four weeks later, rats were either killed or anaesthetized and the ligation clip removed. Following a further 8 weeks, both submandibular ducts were cannulated under terminal anaesthesia. Salivary flows were then stimulated electrically (chorda-lingual nerve at 2, 5 and 10 Hz) and subsequently by methacholine (whole-body infusion at two doses). Glands were excised, weighed and divided for further in vitro studies or fixed for histological examination. Ligation of ducts caused 75% loss of gland weight, with the loss of most acinar cells. Of the remaining acini, only 50% were innervated despite unchanged choline acetyltransferase activity, suggesting few parasympathetic nerves had died. Following deligation, submandibular glands recovered half their weight and had normal morphology. Salivary flows from both glands (per unit of gland tissue) were similar when evoked by methacholine but greater from the deligated glands when evoked by nerve stimulation. This suggests that parasympathetic nerves had reattached to new target cells in the recovered glands at a greater ratio than normal, confirming reinnervation of the regenerating gland.
Assuntos
Plasticidade Neuronal/fisiologia , Sistema Nervoso Parassimpático/fisiologia , Glândula Submandibular/inervação , Glândula Submandibular/patologia , Animais , Atrofia/etiologia , Cálcio/metabolismo , Estimulação Elétrica , Ligadura , Masculino , Cloreto de Metacolina/farmacologia , Sistema Nervoso Parassimpático/efeitos dos fármacos , Parassimpatomiméticos/farmacologia , Ratos , Ratos Wistar , Glândula Submandibular/metabolismoRESUMO
The mechanism by which solutions containing polyphenols are perceived as astringent is not clearly understood. Salivary proline-rich proteins and histatins are products of salivary glands and rapidly bind polyphenols - thought to be the main astringent compound in such as tea and wine. However it is unclear how this interaction leads to the altered oral mouthfeel known as astringency which is characterised by a dry, puckered feeling all around the mouth. To determine the role of saliva in the perception of astringency a protocol was used to decrease the volume of saliva from the mouth (by washing with water) and then by chewing to increase the volume of saliva above resting levels. Following each of these conditions subjects tasted the same solution of black tea and were asked to rate the relative astringency. Compared to the astringency rating of black tea at rest the majority of subjects (10 out of 15) perceived an increase in astringency following washing the mouth with water. Most subjects then perceived a decrease in astringency following chewing compared to the previous state. In all subjects a reduction in salivary proteins was detected following water washout and an increase above resting levels detected following chewing although there was no change in oral mucosal wetness. A separate experiment revealed several of the proteins interacting following the water washout were salivary in origin. We conclude that salivary proteins in solution inhibit the mouthfeeling of astringency which is mediated, at least in part, by salivary proteins adhered to buccal mucosal cells.
Assuntos
Adstringentes/farmacologia , Saliva/efeitos dos fármacos , Percepção Gustatória/efeitos dos fármacos , Chá , Adulto , Análise de Variância , Estudos Cross-Over , Feminino , Humanos , Masculino , Modelos Biológicos , Psicofísica , Saliva/metabolismo , Proteínas e Peptídeos Salivares/metabolismo , Taxa Secretória/efeitos dos fármacos , Estimulação Química , Fatores de TempoRESUMO
OBJECTIVE: The commonly associated aetiology of salivary gland inflammation and salivary hypofunction has led to the widely held belief that inflammation causes salivary gland hypofunction. Indeed, our own recent study seemed to support this contention. Here, we tested the hypothesis that, in an acute duct ligation model, eliminating inflammation the submandibular gland would recover normal function. MATERIALS AND METHODS: Ligation of the rat submandibular gland excretory duct for 24 h was used to induce inflammation and salivary gland hypofunction. A group of duct ligated rats was compared with a second group given dexamethasone, on the day of duct ligation. Twenty-four hours later salivary gland function was assessed and salivary glands were collected. RESULTS: Histology and myeloperoxidase activity assay revealed a profound decrease in inflammatory cell infiltration of ligated glands from rats given dexamethasone, compared with ligated glands in the absence of dexamethasone. Salivary flow rate evoked by methacholine was decreased (P < 0.01) by approximately 56% (ligated vs control, 79 +/- 9 microl min(-1) g(-1)vs 177 +/- 11 microl min(-1) g(-1)) and salivary flow from ligated dexamethasone-treated and ligated glands was similar. CONCLUSION: Despite eliminating the inflammatory reaction in the ligated gland, salivary hypofunction was not reversed, suggesting that other mechanisms must be at work in the ligation-induced salivary hypofunction.
Assuntos
Ductos Salivares/fisiopatologia , Sialadenite/fisiopatologia , Doenças da Glândula Submandibular/fisiopatologia , Glândula Submandibular/fisiopatologia , Xerostomia/fisiopatologia , Doença Aguda , Animais , Anti-Inflamatórios/uso terapêutico , Dexametasona/uso terapêutico , Modelos Animais de Doenças , Glucocorticoides/uso terapêutico , Ligadura , Macrófagos/patologia , Cloreto de Metacolina/farmacologia , Neutrófilos/patologia , Parassimpatomiméticos/farmacologia , Peroxidase/análise , Potenciometria , Ratos , Ratos Wistar , Saliva/efeitos dos fármacos , Saliva/metabolismo , Ductos Salivares/efeitos dos fármacos , Ductos Salivares/patologia , Ductos Salivares/cirurgia , Proteínas e Peptídeos Salivares/análise , Taxa Secretória/efeitos dos fármacos , Taxa Secretória/fisiologia , Sialadenite/tratamento farmacológico , Sialadenite/patologia , Glândula Submandibular/efeitos dos fármacos , Glândula Submandibular/patologia , Glândula Submandibular/cirurgia , Doenças da Glândula Submandibular/patologia , Fatores de Tempo , Xerostomia/patologiaRESUMO
OBJECTIVE: Immunoglobulin A (IgA) is transported across glandular epithelial cells by polymeric immunoglobulin receptor (plgR), with each receptor molecule participating in only one round of transcytosis. Nerve-related stimuli rapidly increase salivary secretion of IgA, while concentrations are increased in the autoimmune disease Sjögren's syndrome. Our aim here was to determine whether autonomic agonists and cytokines present in Sjögren's-affected glands can up-regulate salivary cell plgR expression. METHODS: Cultures of rat parotid acinar cells (PAR C5) and human submandibular gland ductal cells (HSG) were exposed to carbachol or adrenaline for 24 h and to interleukin-4 and/or interferon-gamma for 48 h. The human colonic cell line HT-29 served as a positive control for cytokine response. plgR mRNA was quantified by reverse transcription and real-time PCR and protein expression was examined by immunoblotting. RESULTS: Carbachol increased plgR mRNA levels significantly in all cells but adrenaline did so only with PAR cells (P<0.05). HSG and HT-29 cells both up-regulated plgR gene transcription on exposure to interleukin-4 and interferon-gamma either alone or in combination (P<0.05). By contrast, production of plgR mRNA in PAR cells tended to decrease in response to all cytokine treatments. plgR protein levels rose in line with mRNA expression in cytokine-treated HT-29 cultures (P<0.05). CONCLUSIONS: Autonomimetics can up-regulate plgR transcription in transformed and neoplastic salivary and colonic cells, although intracellular coupling mechanisms require further investigation. Immunomodulatory cytokines increased plgR expression in one of the salivary cell lines, but additional work is needed to establish whether this occurs in Sjögren's patients.
Assuntos
Fármacos do Sistema Nervoso Autônomo/agonistas , Citocinas/farmacologia , Glândula Parótida/efeitos dos fármacos , Receptores de Imunoglobulina Polimérica/efeitos dos fármacos , Síndrome de Sjogren/imunologia , Glândula Submandibular/efeitos dos fármacos , Agonistas Adrenérgicos/farmacologia , Animais , Carbacol/farmacologia , Linhagem Celular , Agonistas Colinérgicos/farmacologia , Epinefrina/farmacologia , Células HT29 , Humanos , Interferon gama/farmacologia , Interleucina-4/farmacologia , Glândula Parótida/citologia , Glândula Parótida/imunologia , RNA Mensageiro/análise , Ratos , Receptores de Imunoglobulina Polimérica/análise , Ductos Salivares/citologia , Ductos Salivares/efeitos dos fármacos , Ductos Salivares/imunologia , Glândula Submandibular/citologia , Glândula Submandibular/imunologia , Fatores de Tempo , Transcrição Gênica/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacosRESUMO
Obesity is a widespread chronic inflammatory disorder characterized by an increased overall disease burden and significant association with periodontitis. The aim of this prospective clinical cohort study was to investigate the effect of obesity on orthodontic tooth movement. Fifty-five adolescent patients (27 males, 28 females) with a mean (SD) age of 15.1 (1.7) years and mean (SD) body mass index (BMI) of 30.2 (3.5) kg/m2 in obese and 19.4 (2.2) kg/m2 in normal-weight groups were followed from start of treatment to completion of tooth alignment with fixed orthodontic appliances. Primary outcome was time taken to complete tooth alignment, while secondary outcomes included rate of tooth movement and change in clinical parameters (plaque/gingival indices, unstimulated whole-mouth salivary flow rate, gingival crevicular fluid biomarkers). Data collection took place at baseline (start of treatment: appliance placement), 1 h and 1 wk following appliance placement, and completion of alignment. Results were analyzed by descriptive statistics followed by generalized estimating equation regression modeling. There were no significant differences between groups in time taken to achieve tooth alignment (mean [SD] 158.7 [75.3] d; P = 0.486). However, at 1 wk, initial tooth displacement was significantly increased in the obese group ( P < 0.001), and after adjusting for confounders, obese patients had a significantly higher rate of tooth movement compared with normal-weight patients (+0.017 mm/d; 95% confidence interval, 0.008-0.025; P < 0.001) over the period of alignment. Explorative analyses indicated that levels of the adipokines leptin and resistin, the inflammatory marker myeloperoxidase (MPO), and the cytokine receptor for nuclear factor kappa-B ligand (RANKL) were significantly different between obese- and normal-weight patients and associated with observed rates of tooth movement. This represents the first prospective data demonstrating a different response in obese patients compared with normal-weight patients during early orthodontic treatment. These differences in the response of periodontal tissues to orthodontic force in the presence of obesity have potential short- and long-term clinical implications.
Assuntos
Obesidade/complicações , Técnicas de Movimentação Dentária , Adolescente , Biomarcadores/análise , Índice de Massa Corporal , Índice de Placa Dentária , Feminino , Líquido do Sulco Gengival/química , Humanos , Masculino , Índice Periodontal , Estudos Prospectivos , Salivação , Fatores de Tempo , Reino UnidoRESUMO
Immunoglobulin A (IgA) is transported into saliva by salivary cells expressing the polymeric immunoglobulin receptor (pIgR). In rat salivary glands, autonomic nerves stimulate this process. To examine how nerves affect pIgR-mediated IgA secretion, the chorda-lingual nerve was sectioned. One week after preganglionic parasympathectomy, both the stimulated and unstimulated rates of salivary IgA secretion were reduced, despite similar glandular amounts of IgA. Biochemical analysis of cells from parasympathectomised and control glands indicated reduced membrane expression of pIgR. It appears the removal of long-term parasympathetic input has affected the routing of pIgR within salivary cells and reduced the SIgA transport into saliva.
Assuntos
Fibras Autônomas Pré-Ganglionares/fisiologia , Regulação para Baixo/imunologia , Imunoglobulina A Secretora/biossíntese , Parassimpatectomia , Saliva/imunologia , Saliva/metabolismo , Glândula Submandibular/imunologia , Glândula Submandibular/inervação , Animais , Separação Celular , Imunoglobulina A/biossíntese , Nervo Lingual/cirurgia , Masculino , Tamanho do Órgão/imunologia , Parassimpatectomia/métodos , Ratos , Ratos Wistar , Proteínas e Peptídeos Salivares/biossíntese , Proteínas e Peptídeos Salivares/metabolismo , Componente Secretório/biossíntese , Glândula Submandibular/metabolismo , Glândula Submandibular/cirurgiaRESUMO
Dietary components rich in polyphenols-for example, tea and red wine-are thought to cause tooth staining. In the present study, hydroxyapatite was used as a model of enamel for study of the influence of salivary proteins on the binding of different polyphenols to hydroxyapatite in vitro. Neither salivary protein pellicles nor salivary proteins in solution significantly altered the binding of the small polyphenol epigallocatechin to hydroxyapatite. However, hydroxyapatite binding of anthocyanin, a small grape-skin-derived polyphenol, or the larger polyphenols of black tea was increased by the presence of salivary proteins, either as a pellicle or in solution. Proline-rich proteins were enriched from parotid saliva and found to increase binding of anthocyanin and black tea polyphenols to hydroxyapatite, while enriched histatins did not increase binding. It is concluded that some salivary proteins, including proline-rich protein, can mediate increased staining of enamel by red-wine- and black-tea-derived polyphenols.
Assuntos
Catequina/análogos & derivados , Película Dentária/metabolismo , Proteínas e Peptídeos Salivares/metabolismo , Chá/efeitos adversos , Descoloração de Dente/metabolismo , Vinho/efeitos adversos , Antocianinas/metabolismo , Catequina/metabolismo , Durapatita/metabolismo , Flavonoides/metabolismo , Humanos , Peptídeos/metabolismo , Fenóis/metabolismo , Polifenóis , Domínios Proteicos Ricos em Prolina , Ligação Proteica , Proteínas/metabolismo , Descoloração de Dente/etiologiaRESUMO
Saliva is vital for the maintenance of normal oral physiology and mucosal health. The loss of salivary function can have far-reaching consequences, as observed with dry mouth, which is associated with increased orodental disease, speech impairment, dysphagia, and a significant negative effect on quality of life. The timely diagnosis of oral dryness is vital for the management of orodental disease and any associated often-undiagnosed systemic disease (e.g., Sjögren syndrome). Our aim was to investigate differences in mucin glycoproteins and saliva rheological properties between sufferers and nonsufferers of dry mouth in order to understand the relationship between saliva composition, rheological properties, and dryness perception and provide additional potential diagnostic markers. All patients exhibited objective and subjective oral dryness, irrespective of etiology. Over half of the patients (n = 20, 58.8%) had a saliva secretion rate above the gland dysfunction cutoff of 0.1 mL/min. Mucin (MUC5B and MUC7) concentrations were generally similar or higher in patients. Despite the abundance of these moisture-retaining proteins, patients exhibited reduced mucosal hydration (wetness) and significantly lower saliva spinnbarkeit (stringiness), suggesting a loss of the lubricating and retention/adhesion properties of saliva, which, at least partially, are associated with mucin glycoproteins. Over 90% of patients with dry mouth (DMPs) consistently had unstimulated whole mouth saliva (UWMS) spinnbarkeit below the proposed normal cutoff (10 mm). Further analysis of mucins revealed the reduced glycosylation of mucins in DMPs compared to healthy controls. Our data indicate that UWMS mucin concentrations are not reduced in dry mouth but that the mucin structure (glycosylation) is altered. UWMS from DMPs had reduced spinnbarkeit, the assessment of which, in conjunction with sialometry, could improve sensitivity for the diagnosis of dry mouth. Additionally, it may be useful to take into consideration the altered mucin glycosylation and saliva rheological properties when designing synthetic or purified mucins for saliva substitutes and dry mouth therapy.
Assuntos
Mucinas/metabolismo , Saliva/fisiologia , Xerostomia/fisiopatologia , Estudos de Casos e Controles , Glicosilação , Humanos , Pessoa de Meia-Idade , Mucinas/análise , Reologia , Saliva/química , Saliva/metabolismo , Salivação/fisiologia , Síndrome de Sjogren/complicações , Síndrome de Sjogren/fisiopatologia , Xerostomia/etiologia , Xerostomia/metabolismoRESUMO
Salivary secretion of immunoglobulin A (IgA) in response to electrical stimulation of the parasympathetic nerve supply was assessed bilaterally in the submandibular glands of anaesthetized rats 1 week following unilateral pre-ganglionic sympathectomy (decentralization). Nerve-mediated stimulation on the non-denervated side increased IgA secretion several fold above an unstimulated rate of secretion whereas sympathetic decentralization reduced the parasympathetically stimulated secretion of IgA without affecting the basal rate. Glandular levels of IgA were increased following decentralization compared to the control glands. Salivary levels of free secretory component (FSC), the cleaved polymeric immunoglobulin receptor (plgR), were increased by parasympathetic stimulation and reduced by sympathectomy, though not as much as IgA. The decreased secretion of FSC suggests a reduced production of plgR and may account in part, for reduced IgA secretion following long-term removal of sympathetic nerve impulses.
Assuntos
Imunoglobulina A/metabolismo , Sistema Nervoso Parassimpático/imunologia , Glândula Submandibular/imunologia , Glândula Submandibular/inervação , Sistema Nervoso Simpático/imunologia , Animais , Estimulação Elétrica , Calicreínas/metabolismo , Nervo Lingual/imunologia , Masculino , Peroxidases/metabolismo , Ratos , Ratos Wistar , Saliva/enzimologia , Saliva/imunologia , Glândula Submandibular/metabolismo , SimpatectomiaRESUMO
Salivary secretion of immunoglobulin A (lgA) by submandibular glands is increased by stimuli from autonomic nerves. Since it is unclear which specific autonomic receptors transduce such stimuli, we have infused autonomimetics intravenously and compared secretion of fluid, IgA and stored proteins (peroxidase and total protein) with secretory responses during electrical stimulation of the parasympathetic nerve supply in anaesthetized rats. The greatest secretion of IgA was evoked by the alpha-adrenoceptor agonist phenylephrine and this was reduced by the beta-adrenoceptor blocking drug propranolol. The secretion of fluid or proteins but not IgA was increased with frequency of nerve stimulation and dose of methacholine (cholinergic), isoprenaline (beta-adrenergic) or phenylephrine (alpha-adrenergic).
Assuntos
Agonistas Adrenérgicos/farmacologia , Vias Autônomas/fisiologia , Imunoglobulina A/metabolismo , Receptores Adrenérgicos alfa/imunologia , Receptores Adrenérgicos beta/imunologia , Glândula Submandibular/inervação , Glândula Submandibular/metabolismo , Antagonistas Adrenérgicos/farmacologia , Agonistas alfa-Adrenérgicos/farmacologia , Agonistas Adrenérgicos beta/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Animais , Vias Autônomas/efeitos dos fármacos , Antagonistas Colinérgicos/farmacologia , Relação Dose-Resposta a Droga , Estimulação Elétrica , Masculino , Fibras Parassimpáticas Pós-Ganglionares/efeitos dos fármacos , Fibras Parassimpáticas Pós-Ganglionares/fisiologia , Ratos , Ratos Wistar , Receptores Adrenérgicos alfa/efeitos dos fármacos , Receptores Adrenérgicos alfa/metabolismo , Receptores Adrenérgicos beta/efeitos dos fármacos , Receptores Adrenérgicos beta/metabolismo , Glândula Submandibular/imunologia , Fibras Simpáticas Pós-Ganglionares/efeitos dos fármacos , Fibras Simpáticas Pós-Ganglionares/fisiologiaRESUMO
Immunoglobulin A (IgA) is the most abundant immunoglobulin in saliva and other mucosal secretions and plays an important role in mucosal immunity. The present study examined whether secretion of IgA, like other salivary proteins, is increased by reflex stimulation. Parotid saliva was collected from subjects into separate vials under resting conditions and during chewing-stimulated secretion over 45 min. Enzyme-linked immunosorbent assay (ELISA) indicated that chewing increased IgA secretion. The extent and pattern of the increase were similar to those of total protein and acinar cell amylase. SDS gel electrophoresis and Western blotting showed that high-molecular-weight forms of IgA-containing secretory component predominated in all saliva samples. Secretory component, the cleaved epithelial receptor for polymeric IgA, was secreted in a pattern very similar to that of IgA. It is concluded that chewing stimulates epithelial cell transcytosis of IgA and increases secretion of secretory IgA into saliva.
Assuntos
Imunoglobulina A Secretora/metabolismo , Mastigação/fisiologia , Saliva/imunologia , Adulto , Amilases/metabolismo , Análise de Variância , Western Blotting , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Células Epiteliais/metabolismo , Exocitose/fisiologia , Humanos , Imunidade nas Mucosas/imunologia , Imunoglobulina A Secretora/análise , Imunoglobulina A Secretora/imunologia , Peso Molecular , Glândula Parótida/imunologia , Glândula Parótida/metabolismo , Reflexo/imunologia , Saliva/enzimologia , Saliva/metabolismo , Proteínas e Peptídeos Salivares/análise , Proteínas e Peptídeos Salivares/metabolismo , Componente Secretório/análise , Componente Secretório/metabolismo , Taxa Secretória , Estatística como Assunto , Fatores de TempoRESUMO
Two runs of one experiment were conducted to study the effects of the presence or absence of satellite (SAT) chick-waterers in conjunction with nipple-drinkers on the mortality and productive performance of mixed-sex, broiler chicks grown to 42 days of age. Data were combined for analysis. The chicks were obtained from dams 29, 31, 61 and 65 wk of age. The treatments were: 1) chicks from 61- and 65-wk-old dams, nipple-drinkers only; 2) chicks from 29- and 31-wk-old dams, nipple-drinkers only; 3) chicks from 61- and 65-wk-old dams, nipple-drinkers plus one SAT-waterer per replication; 4) chicks from 29- and 31-wk-old dams, nipple-drinkers plus one SAT-waterer. The SAT waterers were removed after 11 days. Routine management procedures were followed. The chicks from the older dams (61 and 65 wk of age) were heavier (1.60 versus 1.58 kg, P less than .05) tha those from the young dams (29 and 31 wk of age). Chicks from the young dams had better feed conversion (1.89 versus 1.93 g/g, P less than .01). The age of dam had no effect on the mortality of the broiler chicks. The presence or absence of SAT-waterers had no effect on body weight or feed conversion. A difference (P less than .05) occurred in mortality through 42 days of age; the chicks using the SAT waterers had a lower mortality level (3.23 versus 4.22%), than those using nipple-drinkers. The presence of ST-waterers in conjunction with nipple-drinkers appears to improve livability in broiler chicks.
Assuntos
Galinhas/crescimento & desenvolvimento , Ingestão de Líquidos , Fatores Etários , Animais , Peso Corporal , Feminino , Masculino , MortalidadeRESUMO
Three trials were conducted to study the effects of a high flow volume (2.3 mL/s) nipple waterer (HFN) versus a low flow volume (.4 mL/s) nipple waterer (LFN) on the productive performance of broiler chickens as measured by average body weight (kilograms), average feed conversion (kilograms:kilogram), and percentage mortality rate. Equal numbers of male and female birds were used during Trial 1; only male birds were used during Trials 2 and 3. All trials were conducted during the summer months. An attempt was made during Trial 2 to expose the birds to artificial heat stress. No differences were seen during any of the trials in feed conversion between the two treatments. In Trial 1 the only significant difference (P less than or equal to .05) exhibited was in average male body weight (1.87 kg HFN; 1.84 kg LFN). A highly significant difference (P less than or equal to .01) was seen in average body weight (1.75 kg HFN; 1.64 kg LFN) during Trial 2. Average body weight difference during Trial 3 was highly significant at 42 days of age but not at Day 49. Mortality rate figures during Trial 2 indicate a highly significant difference during the 38-day period prior to heat stress (2.2% LFN; .4% HFN), and significant difference during the heat stress period (38 to 44 days; 2.9% LFN; 1.5% HFN). During Trial 3 mortality rate differences were significant by 49 days (20.6% LFN; 11.4% HFN) although there was no difference at 42 days.(ABSTRACT TRUNCATED AT 250 WORDS)