Relationship between xerostomia and salivary flow rates in HIV-infected individuals.

AIM: The aim of the present study was to determine the relationship between self-reported xerostomia and salivary flow rates among HIV-infected individuals. METHODS: A cross-sectional study was performed on 173 individuals (81 HIV-infected individuals, mean age: 32 years, and 92 non-HIV controls, mean age: 30 years). Subjective complaints of dry mouth, based on a self-report of xerostomia questions, and dry mouth, based on a visual analogue scale (VAS), were recorded along with measurements of salivary flow rate of both unstimulated and wax-stimulated whole saliva. The relationship between subjective responses to the xerostomia questions, the VAS of dry mouth, and objective measurements of salivary flow rates were analyzed. RESULTS: Responses to the questions--Do you carry water or a saliva substitute? and Have you had taste disturbance?--were significantly different between HIV-infected and non-HIV individuals (P < 0.05). Individuals' responses to questions concerning dry mouth were significantly correlated with a low unstimulated salivary flow rate. A significant correlation between the VAS of dry mouth and salivary flow rates was observed (P = 0.023). CONCLUSIONS: Responses to self-reported xerostomia questions reflects low unstimulated salivary flow rates. Thus, questions concerning dry mouth might be useful tools to identify HIV-infected individuals with hyposalivation, especially at a resting stage.

Saliva in relation to dental erosion before and after radiotherapy.

OBJECTIVE: Low saliva flow and abnormal saliva composition are common conditions after radiotherapy for oral cavity and pharyngeal cancer. Both conditions increase the susceptibility to dental caries and erosion, which may be further accelerated by changes in food preferences. The aim of this study was to determine changes in saliva flow and susceptibility to erosive challenges in pharyngeal cancer patients before and after radiotherapy to the head and neck. MATERIALS AND METHODS: The erosive potential of sucking acidic candies with and without calcium was determined in nine patients (50-68 years) before and after receiving a radiation dose of 66 Gy to the head and neck area. The erosive potential was evaluated from saliva degree of saturation with respect to hydroxyapatite (HAp) and by dissolution of HAp in candy-stimulated saliva. RESULTS: Sucking acidic candies increased saliva flow rates ≈ 17-fold before as well as after radiotherapy (p < 0.001). However, significantly lower unstimulated (p < 0.05) and stimulated (p < 0.01) saliva flow rates were obtained after radiotherapy. Also, saliva became more under-saturated with respect to HAp during (p < 0.01) and in a period after sucking the candies (p < 0.01). HAp dissolution was significantly lower with the candy containing calcium compared with the control candy, both before and after radiotherapy (p < 0.001 and p < 0.05). CONCLUSIONS: Radiotherapy to the head and neck area significantly reduced saliva flow and altered saliva composition in a way that may increase the susceptibility to dental disease. However, saliva could be stimulated by acidic candies, which could be made nearly non-erosive even in irradiated patients.

Saliva and plasma TIMP-1 in patients with colorectal cancer: a prospective study.

BACKGROUND AND AIMS: A prospective cross-sectional study was designed to test if total levels of TIMP-1 in saliva and plasma correlated with the diagnosis of colorectal cancer (CRC) in a population with symptoms consistent with this disease. MATERIALS AND METHODS: Stimulated whole saliva and blood samples were collected from 161 individuals referred to colonoscopy with symptoms associated with CRC. The results of the examination, as well as previous and/or current other diseases were recorded. In a blinded study, the authors used an in-house TIMP-1 ELISA previously validated for use in saliva and plasma to determine total levels of TIMP-1. RESULTS: Fifty-six of the patients (35%) were diagnosed with CRC. Plasma TIMP-1 levels were significantly elevated in CRC patients compared with patients with other, non-malignant diseases and individuals without disease. Significant differences in saliva TIMP-1 levels between CRC patients and individuals without CRC could not be demonstrated. In addition, no correlation was found between levels of TIMP-1 in plasma and saliva. CONCLUSION: Total levels of TIMP-1 in saliva do not reflect the presence of CRC, and TIMP-1 saliva measurements thus cannot substitute plasma TIMP-1 measurements in detection of CRC.

Salivary tissue inhibitor of metalloproteinases-1 localization and glycosylation profile analysis.

Salivary tissue inhibitor of metalloproteinases-1 (TIMP-1) has been associated with pathological conditions in the oral cavity, but the origin of TIMP-1 in saliva remains unknown. Hence, we studied the localization of TIMP-1 in salivary gland tissue and also investigated if TIMP-1 found in blood and saliva is identical. Human salivary gland tissue samples (four parotid gland and four submandibular gland biopsies) were analysed for the presence of TIMP-1 mRNA and protein expression. To assess TIMP-1 glycosylation profiles in blood and saliva, the protein was isolated from plasma and unstimulated and stimulated whole saliva as well as stimulated parotid and submandibular saliva and analysed by MALDI-TOF mass spectrometry. TIMP-1 protein was demonstrated in mucous acinar cells of the submandibular gland and in ductal cells of both the parotid and submandibular gland. However, no TIMP-1 mRNA was detected in any of these cells. The glycosylation profiles of TIMP-1 isolated from whole saliva and saliva from the major glands were highly similar. In contrast, a significant difference was found between the glycoprofiles of salivary TIMP-1 and plasma TIMP-1. Although no clear evidence of TIMP-1 transcription in major salivary glands was demonstrated our results suggest that TIMP-1 in saliva does not originate from plasma.

Does hyperbaric oxygen treatment have the potential to increase salivary flow rate and reduce xerostomia in previously irradiated head and neck cancer patients? A pilot study.

Irradiated head and neck cancer survivors treated in the Hyperbaric Oxygen (HBO) Unit, Copenhagen University Hospital, spontaneously reported improvement of radiation-induced dry mouth feeling. The aim of this pilot study was to evaluate salivary flow rate and xerostomia before and after HBO in irradiated head and neck cancer patients. Eighty patients eligible for HBO treatment on the indication of prevention/treatment of osteoradionecrosis or soft tissue radiation injury were consecutively sampled, of whom 45 had hyposalivation (i.e. unstimulated whole saliva (UWS) flow rate <0.1ml/min), and 69 complained of xerostomia. UWS and stimulated whole saliva (SWS) were collected prior to and after 30 sessions of hyperbaric oxygen treatment over 6weeks. Xerostomia was assessed using the visual analogue scale (VAS). Each HBO session involved compression to 243kPa (2.4 ATA) for 90min while breathing 100% oxygen from a facemask or hood. There was a significant decrease in xerostomia (p<0.001) and slight increase in UWS (p<0.001) and SWS (p<0.001) flow rate, from before HBO as compared to after. Twenty-five of 45 patients with hyposalivation achieved an increased UWS flow rate after HBO. In 12 of these, the flow rates increased to levels not associated with hyposalivation. Patient-assessed improvement of xerostomia and slightly increased UWS and SWS secretion after HBO treatment suggest that HBO may have a beneficial effect on radiation-induced salivary gland damage.

Associations between labial and whole salivary flow rates, systemic diseases and medications in a sample of older people.

OBJECTIVE: To investigate the associations between age, gender, systemic diseases, medications and labial and whole salivary flow rates in older people. METHODS: Unstimulated labial (LS) and unstimulated (UWS) and chewing-stimulated (SWS) whole salivary flow rates were measured in 389 randomly selected community-dwelling Danish women and 279 men aged 65-97 years. Systemic diseases, medications (coded according to the Anatomical Therapeutic Chemical (ATC) Classification System), tobacco and alcohol consumption were registered. RESULTS: The number of diseases and medications was higher and UWS lower in the older age groups. On average, women were slightly older, had more diseases, higher medication intake and lower UWS, SWS and LS than men. High number of diseases and medications was associated with low UWS, SWS and LS. In the healthy (14%) and nonmedicated (19%) participants, flow rates were not associated with age and gender, apart from SWS being lower in nonmedicated women. Low UWS were associated with psychiatric and respiratory disorders, type 2 diabetes and intake of psycholeptics, psychoanaleptics (especially SRRIs), respiratory agents, oral antidiabetics (particularly sulfonylureas), magnesium-hydroxide, cardiac agents, quinine, thiazides, calcium channel blockers, statins, urinary antispasmodics, glucosamine, NSAIDs, opioids and ophthalmologicals. SWS were lower in participants with ophthalmological disorders using ophthalmologicals (especially antiglaucoma agents and miotics), but also in those taking antidepressants, cardiac agents (mostly digitalis glycosides) and calcium channel blockers. Cardiovascular diseases and intake of anti-thrombotics (mainly low dose aspirins), calcium channel blockers and oral antidiabetics were associated with low LS. CONCLUSIONS: In older people, low salivary flow rates are associated with specific and high number of diseases and medications, but neither with age and gender per se nor with tobacco and alcohol consumption. Low UWS are associated with more diseases and medications than SWS and LS, which were primarily associated with cardiovascular diseases and medications including preventive agents such as low-dose aspirins and statins. New insights into medications and their association with salivary gland function were achieved using the ATC classification system.

Hyposalivation, xerostomia and oral health status of HIV-infected subjects in Thailand before HAART era.

BACKGROUND: The aims of this study were to determine hyposalivation, xerostomia, and oral health status of HIV-subjects in Thailand before highly active antiretroviral therapy era. METHODS: Oral examination and measurement of saliva flow rate of both unstimulated and wax-stimulated whole saliva were performed in 135 subjects (56 HIV-subjects, mean age: 34.5 years, and 79 non-HIV controls, mean age: 29.5 years). Presence of oral candidiasis, cervical root caries, and number of existing teeth were recorded. Microbiological investigation of oral Candida was conducted using oral rinse technique. Risk factors associated with hyposalivation and xerostomia were analysed. RESULTS: The unstimulated flow rates in HIV-subjects and non-HIV controls were 0.19 and 0.33 ml/min (P = 0.0024). For stimulated flow rates, the corresponding figures were 1.45 and 1.62 ml/min (P = 0.31). The unstimulated flow rate was significantly higher in the asymptomatic HIV-subjects: 0.17 ml/min, when compared with the symptomatic/AIDS group 0.11 ml/min (P = 0.003). No significant difference between the groups could be found with respect to stimulated flow rate. Hyposalivation was significantly associated with the colony forming unit of Candida. Smoking and alcohol consumption were significantly associated with hyposalivation, but not xerostomia. The following factors were significantly associated with both hyposalivation and xerostomia; sex, stage of HIV infection, risk group of HIV infection, systemic disease, and medication use. CONCLUSIONS: Salivary flow rate of HIV-subjects in Thailand was affected by HIV infection. The rate was significantly decreased with advanced stage of the disease. Various factors including medication use were associated with hyposalivation and xerostomia among the subjects.

Erosive potential of saliva stimulating tablets with and without fluoride in irradiated head and neck cancer patients.

BACKGROUND: Patients irradiated in the head and neck region often suffer from severe dry mouth and use acidic saliva stimulating products, which may cause erosion of teeth. PURPOSE: To determine saliva stimulating effects and erosive potential (EP) of acidic saliva stimulating tablets (Xerodent) with and without fluoride in irradiated head and neck cancer patients. MATERIALS AND METHOD: Nineteen irradiated patients (median age 57 years) sucked Xerodent tablets with and without fluoride. Saliva collections were divided into three 10-min sessions in the sequence: unstimulated whole saliva, Xerodent stimulated saliva without fluoride, and with fluoride. Saliva pH was determined without loss of CO(2) and in combination with inorganic measures used to calculate the degree of saturation of hydroxyapatite (HAp) and fluorapatite (FAp). EP was determined directly in all saliva samples by monitored dissolution of HAp crystals. RESULTS: Saliva flow rates increased significantly (15-fold) when sucking both tablets (p<0.001). Major changes in saliva composition caused undersaturation of HAp in some samples. However, no dissolution of HAp occurred in the saliva obtained with any of the two tablets. This was most likely due to the limited drop in pH resulting in saliva that was still supersaturated with respect to FAp. CONCLUSION: Both Xerodent with and without fluoride were evaluated as non-erosive, however, for additional caries protection the fluoride variant is preferable.

Salivary changes and dental erosion in bulimia nervosa.

OBJECTIVE: Our aim was to study if bulimia nervosa (BN) has an impact on salivary gland function and if such changes are related to dental erosion. STUDY DESIGN: Twenty women with BN and twenty age- and gender-matched controls participated. Flow rate and composition of whole and glandular saliva, as well as feeling of oral dryness were measured. Dental erosion was measured on casts. RESULTS: Compared with control subjects, unstimulated whole saliva (UWS) flow rate was reduced in persons with BN, primarily owing to intake of medication (P = .007). No major compositional salivary changes were found. In the BN group, the dental erosion score was highest and complaints of oral dryness were more frequent. CONCLUSIONS: The BN persons had impaired UWS, mainly owing to medication; increased feeling of oral dryness; and more dental erosion. Dental erosion was related to the duration of eating disorder, whereas no effect of vomiting frequency or intake of acidic drinks on reduced UWS was observed.

Oral mucosal lesions, microbial changes, and taste disturbances induced by adjuvant chemotherapy in breast cancer patients.

OBJECTIVE: The aim of the study was to examine oral mucosal lesions, microbial changes, and taste disturbances induced by adjuvant chemotherapy (CT) in breast cancer patients during and 1 year after treatment. STUDY DESIGN: Forty-five consecutive breast cancer patients, eligible for adjuvant CT with cyclophosphamide, epirubicin or methotrexate, and 5-fluorouracil were followed before, during, 6 months and 1 year after CT and were compared to a control group of 31 breast cancer patients not receiving adjuvant CT. RESULTS: During CT, oral mucosal lesions developed including erythema (n = 10, 22%) and ulceration (n = 7, 16%). Five patients (11%) were diagnosed with oral candidosis. Scores of dental bacterial plaque and gingival inflammation increased during CT and the oral microbial composition changed towards a more acidophilic flora. Taste disturbances were experienced by 84% (n = 38) of the patients in the CT group. CONCLUSION: In breast cancer patients, moderate-intensive adjuvant CT caused oral mucosal lesions, oral candidosis, taste disturbances and a more acidophilic oral microflora. These adverse effects were temporary and the majority of the patients were mildly affected.

Meal-induced compositional changes in blood and saliva in persons with bulimia nervosa.

BACKGROUND: Binge eating episodes in persons with bulimia nervosa may to some extent be a result of disturbed sensations of hunger and satiety. It has been hypothesized that abnormal appetite sensations may be due to bulimia nervosa-related alterations in the release of hormones that are known to be involved in the physiologic regulation of appetite and metabolism. OBJECTIVE: The objective was to investigate whether circulating concentrations of the appetite-regulating peptides leptin and ghrelin and markers of metabolism (glucose and insulin) are different in persons with bulimia nervosa than in controls before and after intake of a meal and whether these changes may be reflected in saliva. DESIGN: Twenty women with bulimia nervosa and 20 age- and sex-matched healthy controls participated. After an overnight fast, the subjects ate a standardized carbohydrate-rich breakfast. Whole saliva and blood were collected, and visual analogue scales for hunger and satiety were completed once before and continuously for 5 h after the breakfast. RESULTS: A lower pre- and postprandial whole saliva flow rate was found in subjects with bulimia nervosa, which might have been attributable to a concomitant intake of potentially xerogenic medication. Subjects with bulimia nervosa experienced reduced hunger, which could not be explained by pre- or postprandial alterations in circulating ghrelin, leptin, insulin, or glucose concentrations. CONCLUSIONS: There were no apparent differences in the composition of blood and saliva between bulimia nervosa and control subjects, and meal-induced compositional changes in blood were not directly mirrored in saliva composition.

Adjuvant chemotherapy in breast cancer patients induces temporary salivary gland hypofunction.

It is an open question if chemotherapy (CT) per se imposes adverse effects on salivary gland function. The aim of the present study was to investigate effects of CT on salivary function in breast cancer patients during and after adjuvant CT. Forty-five breast cancer patients, eligible for adjuvant CT with CEF or CMF (cyclophosphamide, epirubicin or methotrexate, 5-fluorouracil) were followed before, during, six months and one year after CT. Findings were compared to those in a control group of 31 breast cancer patients not receiving CT. Flow rates and compositions of unstimulated and stimulated whole saliva as well as stimulated parotid saliva (UWS, SWS and SPS) were measured. Feeling of oral dryness and saliva-related complaints were registered. UWS and SWS flow rates decreased during CT (p<0.001 and p<0.01). UWS remained lower six months after, but reached baseline level within one year. SPS flow rate was not significantly affected, suggesting that the decrease in whole saliva production is accounted for by decreased acinar saliva formation by the submandibular glands. Twenty patients (44%) suffered from hyposalivation (UWS < or = 0.1 ml/min and/or SWS < or = 0.5 ml/min) during CT. Xerostomia scores rose during CT and stayed elevated one year after treatment. CT also induced compositional changes by slightly increasing salivary sodium and chloride concentrations as well as decreasing inorganic phosphate concentrations in spite of lower or unchanged flow rates, implying that ductal modification mechanisms are affected. UWS and SWS total protein output and UWS secretory IgA output decreased in response to CT. Thus, the results suggest that acinar and ductal cell functions are affected by adjuvant CT. These adverse drug reactions are temporary, as salivary findings generally returned to baseline values within one year following treatment.

Whole saliva in X-linked hypohidrotic ectodermal dysplasia.

BACKGROUND: X-linked hypohidrotic ectodermal dysplasia (HED) is the most common type of ectodermal dysplasia. Identification of female carriers of X-linked HED can be difficult because of varying degrees of clinical symptoms due to the X-chromosome inactivation. This is the first study about whole saliva flow and composition in males affected by HED and female carriers all confirmed by molecular genetic analysis. HYPOTHESIS AND AIM: As salivary glands derive from ectoderm, we hypothesized that whole saliva flow and composition are altered in males affected by HED and female carriers. DESIGN: Saliva flow and composition were examined in a group of affected males and in a group of female carriers, all confirmed by molecular genetic analysis, and compared with healthy male and female controls. RESULTS: Affected males and female carriers had reduced whole saliva flow and saliva with high concentrations of most inorganic salivary constituents as well as total protein. However, affected males and female carriers seemed to have reduced amylase activity and concentration relative to their total protein concentration. CONCLUSION: Saliva flow and composition may be used as part of a comprehensive clinical examination to identify potential female carriers of HED.

Salivary changes and dental caries as potential oral markers of autoimmune salivary gland dysfunction in primary Sjogren's syndrome.

BACKGROUND: the classification criteria for primary Sjogren's syndrome (pSS) include a number of oral components. In this study we evaluated if salivary flow and composition as well as dental caries are oral markers of disease severity in pSS. METHODS: in 20 patients fulfilling the American-European Consensus criteria for pSS and 20 age-matched healthy controls whole and parotid saliva flow rates and composition, measures of oral dryness, scores of decayed, missing and filled tooth surfaces (DMFS), periodontal indices, oral hygiene, and dietary habits were examined. RESULTS: in pSS, salivary flow rates, pH, and buffer capacities were lower, and DMFS, salivary sodium and chloride concentrations higher than in the healthy controls. DMFS also correlated inversely to salivary flow rates and positively to oral dryness. Apart from slightly increased gingival index, and more frequent dental visits in pSS, the periodontal condition, oral hygiene or sugar intake did not differ between these two groups. In pSS, findings were correlated to labial salivary gland focus score (FS) and presence of serum-autoantibodies to SSA/SSB (AB). The patients having both presence of AB and the highest FS (>2) also had the highest salivary sodium and chloride concentrations, the lowest salivary phosphate concentrations, lowest salivary flow rates, and highest DMFS compared to those with normal salivary concentrations of sodium and chloride at a given flow rate. CONCLUSION: the salivary changes observed in some pSS patients reflect impaired ductal salt reabsorption, but unaffected acinar transport mechanisms, despite low salivary secretion. Our results suggest that changes in salivary flow and composition as well as dental caries may serve as potential markers of the extent of autoimmune-mediated salivary gland dysfunction in pSS. The study also indicates that the ductal epithelium is functionally affected in some pSS patients, which calls for future pathophysiological studies on the mechanisms underlying this impaired salt reabsorption.

Release of peppermint flavour compounds from chewing gum: effect of oral functions.

During chewing, the oral cavity functions like a bellow, forcing volatile flavour compounds into the exhaling air to the nasal compartment. Accordingly, we hypothesised that flavour release from chewing gum is predominantly governed by chewing frequency (CF), although other oral functions, like masseter muscle activity (MMA), chewing force (CFO), and saliva flow rate (SFR), may also play a role. In 10 healthy young males, the retronasal expired air of menthol and menthone from peppermint-flavoured (2%) chewing gum was determined as functions of CF, SFR, MMA, and CFO. The experimental setup comprised three separate series of a 4-min chewing period. These series differed only with respect to CF, i.e., habitual frequency, and 60 and 88 strokes/min. Results showed that more than 50% of the released menthol and menthone could be retrieved in the expired air and saliva. After 2-min of chewing, the concentration of flavour compounds in the expired air depended primarily on MMA and CF, becoming higher with increased MMA and CF. The concentration of flavour compounds in saliva depended primarily on SFR and the duration of the chewing task, becoming lower with high SFR and prolonged chewing duration. An increased volume of saliva in the mouth seemed to keep more flavour compounds in the aqueous phase, thereby diminishing the release via the retronasal route. In conclusion, flavour release to the retronasal compartment was dependent on MMA and CF and influenced by the volume of saliva present in the mouth.

ORAL ADVERSE DRUG REACTIONS TO CARDIOVASCULAR DRUGS.

A great many cardiovascular drugs (CVDs) have the potential to induce adverse reactions in the mouth. The prevalence of such reactions is not known, however, since many are asymptomatic and therefore are believed to go unreported. As more drugs are marketed and the population includes an increasing number of elderly, the number of drug prescriptions is also expected to increase. Accordingly, it can be predicted that the occurrence of adverse drug reactions (ADRs), including the oral ones (ODRs), will continue to increase. ODRs affect the oral mucous membrane, saliva production, and taste. The pathogenesis of these reactions, especially the mucosal ones, is largely unknown and appears to involve complex interactions among the drug in question, other medications, the patient's underlying disease, genetics, and life-style factors. Along this line, there is a growing interest in the association between pharmacogenetic polymorphism and ADRs. Research focusing on polymorphism of the cytochrome P450 system (CYPs) has become increasingly important and has highlighted the intra- and inter-individual responses to drug exposure. This system has recently been suggested to be an underlying candidate regarding the pathogenesis of ADRs in the oral mucous membrane. This review focuses on those CVDs reported to induce ODRs. In addition, it will provide data on specific drugs or drug classes, and outline and discuss recent research on possible mechanisms linking ADRs to drug metabolism patterns. Abbreviations used will be as follows: ACEI, ACE inhibitor; ADR, adverse drug reaction; ANA, antinuclear antigen; ARB, angiotensin II receptor blocker; BAB, beta-adrenergic blocker; CCB, calcium-channel blocker; CDR, cutaneous drug reaction; CVD, cardiovascular drug; CYP, cytochrome P450 enzyme; EM, erythema multiforme; FDE, fixed drug eruption; I, inhibitor of CYP isoform activity; HMG-CoA, hydroxymethyl-glutaryl coenzyme A; NAT, N-acetyltransferase; ODR, oral drug reaction; RDM, reactive drug metabolite; S, substrate for CYP isoform; SJS, Stevens-Johnson syndrome; SLE, systemic lupus erythematosus; and TEN, toxic epidermal necrolysis.

[Research conditions at the preclinical medical, odontological and pharmaceutical fields]. / Forskningens vilkår ved den medicinske praeklinik samt de odontologiske og farmaceutiske områder.

The Danish Medical Research Council has recently published a report (in Danish) entitled "Research Conditions in the Pre-clinical and Dental Institutes of the Health Science Faculties and the Danish University of Pharmaceutical Sciences". According to this report, the Danish educational institutions within health sciences are facing a major generational change among the scientific staff within the coming 5-15 years. It is therefore worrying that young physicians, dentists and pharmacists refrain from choosing a university research career. Possible explanations include more attractive working conditions, salaries, and career possibilities outside universities. The analyses describe a number of problems regarding this matter and outline how the situation might be improved. The Council recommends that to ensure a future optimal staff balance, focus should be placed on recruitment of researchers. It is important that the future scientific staff also includes a substantial number who possess the specific education provided by the faculty. The staff should be made up of a mix of researchers with knowledge about the nature and practice of their specific discipline and researchers with other scientific backgrounds in the health sciences. It is this interplay between the basic and clinical disciplines that must be consolidated in order to meet the future challenges. The interdisciplinary nature of Danish health science has undoubtedly contributed to placing the Danish health care services in the international front line.

Xerostomia and hypofunction of the salivary glands in cancer therapy.

This review presents data from the literature on oral adverse reactions from the perspectives of subjective feelings of dry mouth (xerostomia) and objective measures of salivary gland hypofunction during and after cancer therapy. Special emphasis is paid to the mechanisms behind xerostomia, impaired saliva secretion and changes in the composition of saliva and to how these relate to radiation therapy involving the salivary glands and to systemic chemotherapy. The oral complications that relate to such iatrogenic changes in salivary gland function are also discussed.

Nitric oxide signalling in salivary glands.

Nitric oxide (NO) plays multiple roles in both intracellular and extracellular signalling mechanisms with implications for health and disease. This review focuses on the role of NO signalling in salivary secretion. Attention will be paid primarily to endogenous NO production in acinar cells resulting from specific receptor stimulation and to NO-regulated Ca2+ homeostasis. Due to the fact that NO readily crosses membranes by simple diffusion, endogenous NO may play a physiological role in processes as diverse as modifying the secretory output, controlling blood supply to the gland, modulating transmitter output from nerve endings, participating in the host defence barrier, and affecting growth and differentiation of surrounding tissue. Furthermore, the role of NO in the pathogenesis of human oral diseases will be considered.