Sjögren's syndrome in the NOD mouse model is an interleukin-4 time-dependent, antibody isotype-specific autoimmune disease

NOD.B10-H2b and NOD/LtJ mice manifest many features of primary and secondary Sjögren's syndrome (SjS), respectively, an autoimmune disease affecting primarily the salivary and lacrimal glands leading to xerostomia (dry mouth) and xerophthalmia (dry eyes). A previous study suggested that the T(H2) cytokine, interleukin (IL)-4, plays an integral role in the development and onset of SjS-like disease in the NOD mouse model. To define further the role of IL-4 in onset of murine SjS-like disease, we have examined two IL4 gene knockout (KO) mouse strains, NOD.IL4-/- and NOD.B10-H2b.IL4-/-. Unlike NOD.IL4-/- mice, NOD.B10-H2b.IL4-/- mice are resistant to development of diabetes. The presence of a dysfunctional IL4 gene did not impede leukocyte infiltration of the salivary glands, yet prevented development of secretory dysfunction. Whereas NOD.B10-H2b.IL4-/- mice exhibited many pathophysiological manifestations of SjS-like disease common to the parental strains, these mice failed to produce anti-muscarinic acetylcholine type-3 receptor (M3R) autoantibodies of the IgG1 isotype. Cytokine mRNA expression profiles and adoptive transfers of T lymphocytes from NOD.B10-H2b.Gfp mice into NOD.B10-H2b.IL4-/- mice at different ages suggest IL-4 is required during the pre-clinical disease stage (around 12 weeks of age) to initiate clinical xerostomia. The results of this study indicate that the failure of NOD.IL4-/- and NOD.B10-H2b.IL4-/- mice to synthesize anti-M3R autoantibodies of the IgG1 isotype apparently explains why these mice fail to develop exocrine gland dysfunction, despite exhibiting pre-clinical manifestations of SjS-like disease.

Evaluation of driver stress using biomarker in motor-vehicle driving simulator

Employing the analysis of a biomarker, an oculomotor angle and a subjective evaluation, we have examined the acute, psychological effect human stress of driving using a motor-vehicle driving simulator. Salivary amylase is used as a biomarker, as it is considered to be one of the indicators of sympathetic nervous activity. 20 healthy female subjects in their early twenties were enrolled in this study. The time-course change of their salivary amylase activity (sAMY) is analyzed before and during the driving. At the same time, using a questionnaire, subjective evaluations are conducted with each subject. As for comparison, the effect of operating a car navigation device, which is not directly associated with driving, is also evaluated. Our results indicate that the psychological effect of driving-induced stress, a condition that can not be easily detected or recognized by a subjective evaluation, is quickly quantified using a biomarker in saliva. Moreover, the results suggest that operation of a non-driving-related device may also reduce the capacity to concentrate on driving. These data imply that evaluation of driver stress using a biomarker can be very useful for improvement of safety during driving.

Submandibular gland mucocele: report of two cases

Submandibular gland mucocele should be remembered in the differential diagnosis of swelling at the submandibular triangle. In the cystic lesion of the submandibular area, the biochemical analysis of aspirated material for amylase should be performed. The cases with submandibular gland mucocele should be treated by removing the lesion with both the submandibular and the sublingual glands.

Clock gene expression in the submandibular glands

Clock genes, which mediate molecular circadian rhythms, are expressed in a circadian fashion in the suprachiasmatic nucleus and in various peripheral tissues. To establish a molecular basis for circadian regulation in the salivary glands, we examined expression profiles of clock-related genes and salivary gland-characteristic genes. Clock-related genes-including Per1, Per2, Cry1, Bmal1, Dec1, Dec2, Dbp, and Reverbalpha-showed robust circadian expression rhythms in the submandibular glands in 12:12-hour light-dark conditions. In addition, a robust circadian rhythm was observed in amylase 1 mRNA levels, whereas the expression of other salivary-gland-characteristic genes examined was not rhythmic. The Clock mutation resulted in increased or decreased mRNA levels of Per2, Bmal1, Dec1, Dec2, and Dbp, and in Cry1-/- background, Cry2 disruption also increased or decreased mRNA levels of these clock-related genes and the amylase 1 gene. These findings indicate that the Clock- and Cry-dependent molecular clock system is active in the salivary glands.

The differentiation between pancreatic neoplastic cysts and pancreatic pseudocyst

The number of small and often asymptomatic cystic lesions detected in pancreas has increased during the last decade. Historically the vast majority of the pancreatic cystic lesions were considered pseudocysts, but in recent series the incidence of various neoplastic cysts, such as intraductal papillary mucinous neoplasm, serous cystadenomas and cystic endocrine tumours, has increased. The possible malignant potential in these cystic neoplasms warrants careful diagnostic workup to choose the optimal treatment for each patient. Patient's age, symptoms and a possible history of acute or chronic pancreatitis with known aetiology together with high quality imaging studies are important in the differential diagnosis between pseudocysts and neoplastic cysts. Endoscopic ultrasound, cyst fluid analysis and positron emission tomography may be used in selected patients, but the accuracy of these methods needs further investigation.

Exhaled breath condensate cytokine patterns in chronic obstructive pulmonary disease

Differences in cytokine patterns in stable chronic obstructive pulmonary disease (COPD), exacerbated COPD, smokers without apparent COPD, and healthy volunteers should be of interest for pathophysiological and therapeutic reasons. Methods including lavage, biopsy and sputum have been employed to investigate cytokines in the lung. For asystematic comparison, exhaled breath condensate (EBC) appears to be well suited. We investigated healthy volunteers, smokers without apparent COPD, stable and exacerbated COPD patients (+/- inhalative steroids) and finally those whose exacerbation made mechanical ventilation inevitable, for a more complete picture of inflammatory cytokines in COPD. We chose EBC because it is non-invasive and can be used repeatedly in spontaneous breathing individuals and during mechanical ventilation. EBC cytokines (IL-1 beta, IL-6, IL-8, IL-10, IL-12 p 70, TNF-alpha) were assayed from a single sample using a multiplex array test kit. We observed a significant increase of all cytokines in acute exacerbation compared to stable COPD, smokers, and volunteers. Stable COPD and volunteers exhibited only small differences in cytokine pattern with respect to IL-1 beta and IL-12 (P<0.01). Smokers had increased levels of all investigated cytokines (P<0.01) compared to non-smokers and, with the exception of IL-1 beta, to stable COPD. Inhaled steroids resulted in reduced levels of IL-1 beta, IL-6, IL-8, IL-10, and IL-12 (all: P<0.01) in stable COPD (all: ex-smokers) with dose dependency for IL-8, IL-1 beta and IL-12. EBC analysis successfully characterized important differences in stable COPD compared to exacerbation or smoking and non-smoking healthy individuals.

Parapapillary choledochoduodenal fistula associated with cholangiocarcinoma

Parapapillary choledochoduodenal fistula is a rare disorder. We herein report a case of parapapillary choledochoduodenal fistula associated with cholangiocarcinoma. A 61-year-old woman was admitted to our hospital for further examination of a liver tumor. She had no clinical symptoms, but computed tomography scans showed an irregularly contoured liver tumor which was histologically confirmed to be adenocarcinoma, by a needle biopsy examination. Duodenal fiberscopy revealed a fistula orifice 1.0 cm proximal to the orifice of the papilla of Vater, and endoscopic retrograde cholangiography through the fistula showed a communication to the common bile duct. Hypotonic duodenography demonstrated reflux of contrast material into the choledochoduodenal fistula. The bile sample collected from the common bile duct showed extremely high levels of pancreatic enzymes, including amylase, phospholipase-A2, and elastase-I. Furthermore, Helicobacter DNA was detected in bile by polymerase chain reaction (PCR) analysis. This experience suggests to us that parapapillary choledochoduodenal fistula may be a risk factor for biliary tract carcinoma, and surgical management is the treatment of choice for this rare condition, even when the patient has no significant clinical symptoms.

The use of low dose octreotide prophylaxis in pancreatic transplants with enteric drainage. Results of a prospective randomized single center trial

AIM

The aim of this study was to investigate the effect of octreotide in the perioperative course of pancreas transplants drained into the bowel in terms of fistula formation, pancreatitis, hemorrhage and thrombosis, and to compare the results to patients not receiving octreotide in a prospectively, randomized single center trial.

PATIENTS AND METHODS

Forty pancreas transplant recipients were prospectively randomized to either receive or not to receive octreotide 0.1 mg subcutaneously at the time of operation and 3x/d there after until post-operative day 7. The incidence of pancreatic leakage from the anastomosis and the content of peritoneal fluid drainage regarding amylase and lipase concentrations collected by abdominal drains were registered on day 0-10. Both groups were comparable for age, sex, onset of diabetes, surgical procedure and immunosuppressive regimen.

RESULTS

There were 35 simultaneous pancreas-kidney transplants and five solitary pancreas transplants, two in the octreotide and three in the control group two pancreas after kidney, one pancreas after liver pancreas, one pancreas after simultaneous pancreas kidney transplantation, one pancreas transplant alone. All had enteric drainage. Twenty patients received octreotide and 20 did not. In one patient, receiving octreotide the pancreas had to be removed for septic complications because of an enteric fistula arising from the anastomosis (1/20 = 5%). The incidence in patients on octreotide vs. non-octreotide was 1 vs. 0 for pancreatitis, 2 vs. 3 for hemorrhage, 2 vs. 1 for thrombosis and 2 vs. 0 for pancreatic fistulae resulting in an actual overall 12 months patient survival of 100% in both groups and a pancreas survival of 85% vs. 95%. For primary simulaneous pancreas kidney the pancreas graft survival was 93%. The amylase and lipase concentrations of fluid collections drained into the peritoneum on day 0 to 10 post-operatively indicating pancreatic fistulization was comparable in both groups.

CONCLUSION

The use of octreotide following pancreas transplantation did not prevent pancreatic fistula formation from the anastomosis neither from the pancreatic capsule in pancreas transplantation with enteric drainage. Further studies are required to finally evaluate the benefit of this prophylactic treatment.

The value of biliary amylase and Hepatocarcinoma-Intestine-Pancreas/Pancreatitis-associated Protein I (HIP/PAP-I) in diagnosing biliary malignancies

BACKGROUND/OBJECTIVES

Elevated concentrations of Hepatocarcinoma-Intestine-Pancreas/Pancreatitis-associated Protein I (HIP/PAP-I) in pancreatic juice have been reported in patients with pancreatic adenocarcinoma and have been considered as a promising tumor marker. This study was conducted to investigate whether biliary HIP/PAP-I can be used in the differential diagnosis of the cause of biliary obstruction.

METHODS

Bile was obtained from patients with bile duct obstruction on the day of biliary drainage. The etiology of biliary obstruction included gallstones (n = 131), pancreatic cancer (n = 32), cholangiocarcinoma (n = 47), papilla Vater cancer (n = 13), hepatocellular carcinoma (n = 4) and metastatic cancer (n = 16). In addition to HIP/PAP-I, the samples were analyzed for amylase to check for the presence of pancreaticobiliary reflux.

RESULTS

The biliary concentration of HIP/PAP-I was not statistically different between patients with gallstones (median, 9.70 ng/mL; interquartile range [IQR] 1.80-45.75) and cancers (median, 12.70 ng/mL; IQR, 3.85-36.75), P > 0.05. However, the amylase activity in the bile was markedly elevated in patients with gallstones (median, 228 U/L; IQR, 40-1965), compared to those with cancer (median, 32 U/L; IQR; 30-176), P < 0.001. The area under the ROC curve of amylase was 0.751 (95% CI: 0.69 to 0.81). At a cut-off value of 46 U/L, the biliary amylase distinguished patients with malignant obstruction from those with benign obstruction with a sensitivity of 66% and a specificity of 74%.

CONCLUSIONS

Our data suggest that the biliary HIP/PAP-I measurement is not useful for differentiating causes of biliary obstruction. The divergent extent and duration of biliary obstruction caused by neoplasm and gallstones may contribute to the significant difference in the amylase activity in bile. Thus, amylase in bile represents a candidate marker in the differential diagnosis of the cause of biliary obstruction.

Biological deinking of inkjet-printed paper using Vibrio alginolyticus and its enzymes

Recycling of office waste paper (photocopy, inkjet, and laser prints) is a major problem due to difficulty in removal of nonimpact ink. Biological deinking of office waste paper is reported using several microorganisms and their enzymes. We report here deinking and decolorization of the dislodged ink particles from inkjet printed paper pulp by a marine bacterium, Vibrio alginolyticus isolate no. NIO/DI/32, obtained from marine sediments. Decolorization of this pulp was achieved within 72 h by growing the bacterium in the pulp of 3-6% consistency suspended in seawater. Immobilized bacterial cells in sodium alginate beads were also able to decolorize this pulp within 72 h. The cell-free culture supernatant of the bacterium grown in nutrient broth was not effective in deinking. However, when the culture was grown in nutrient broth supplemented with starch or Tween 80, the cell-free culture supernatant could effectively deink and decolorize inkjet-printed paper pulp within 72 h at 30 degrees C. The culture supernatant of V. alginolyticus grown in the presence of starch or Tween 80 showed 49 U ml(-1) and 33 U ml(-1) amylase and lipase activities, respectively. Dialysis of these culture supernatants through 10 kDa cut-off membrane resulted in a 35-40% reduction in their efficiency in decolorizing the pulp. It appears that amylase and lipase effectively help in dislodging the ink particles from the inkjet printed-paper pulp. We hypothesize that the bacterium might be inducing the formation of low molecular weight free radicals in the culture medium, which might be responsible for decolorization of the pulp.

[Variation of ecological status of Norwegian Sea water determined from hydrolytic enzyme activities]

The capacity of biopolymer transformation involving efficient and highly specific natural enzyme mechanisms was studied in seawater of the dynamic zone of the Norwegian Sea (the Voring Plateau region). Vertical and spatial variation of proteinase and amylase activities was demonstrated in seawater and the potential rates of degradation of specific substrates, azocasein and Procion-5CX-modified starch, were calculated. High proteolytic activity was demonstrated for the upper photic layer (0-10 m) in the southwestern part of the polygon (up to 88 U/l; v(pr) = 7.04 mg/l/h). Proteolytic activity in the abyssal layer (1500 m and below) sharply decreased to 8-16 U/1; v(pr) = 0.64-1.28 mg/l/h. Similar to other regions of the ocean, the pattern of amylase activity in seawater included low rates of polysaccharide destruction (0-4 U/I; v(st) = 0-0.2 mg/l/h) in water with high proteolytic capacity and, conversely, the top amylase activity (up to 246-490 U/l; v(st) 12.3-24.5 mg/l/h) in seawater layers with undetectable or low proteolytic activity. The spatial distribution of the enzyme activities can indicate the presence of water bodies of different genesis. In the southwestern part of the polygon, statistical analysis demonstrated high correlation between hydrophysical indices (temperature, salinity, and salinity gradient) and proteinase and amylase activities. The ecological evaluation based on express enzyme-substrate tests demonstrated a stressful situation for destruction of organic compounds of protein nature in both the photic layer and the layers below 1000 m (t(pr) > or = 10 h).

Performance evaluation of salivary amylase activity monitor

In order to quantify psychological stress and to distinguish eustress and distress, we have been investigating the establishment of a method that can quantify salivary amylase activity (SMA). Salivary glands not only act as amplifiers of a low level of norepinephrine, but also respond more quickly and sensitively to psychological stress than cortisol levels. Moreover, the time-course changes of the salivary amylase activity have a possibility to distinguish eustress and distress. Thus, salivary amylase activity can be utilized as an excellent index for psychological stress. However, in dry chemistry system, a method for quantification of the enzymatic activity still needs to be established that can provide with sufficient substrate in a testing tape as well as can control enzymatic reaction time. Moreover, it is necessary to develop a method that has the advantages of using saliva, such as ease of collection, rapidity of response, and able to use at any time. In order to establish an easy method to monitor the salivary amylase activity, a salivary transcription device was fabricated to control the enzymatic reaction time. A fabricated salivary amylase activity monitor consisted of three devices, the salivary transcription device, a testing-strip and an optical analyzer. By adding maltose as a competitive inhibitor to a substrate Ga1-G2-CNP, a broad-range activity testing-strip was fabricated that could measure the salivary amylase activity with a range of 0-200 kU/l within 150 s. The calibration curve of the monitor for the salivary amylase activity showed R2=0.941, indicating that it was possible to use this monitor for the analysis of the salivary amylase activity without the need to determine the salivary volume quantitatively. In order to evaluate the assay variability of the monitor, salivary amylase activity was measured using Kraepelin psychodiagnostic test as a psychological stressor. A significant difference of salivary amylase activity was recognized between the pre-stress and mid-stress periods. This study demonstrated that broad-range salivary amylase activity monitor was developed that could be used with only 5 microl of saliva.

Mechanism of exocrine pancreatic insufficiency in streptozotocin-induced diabetes mellitus in rat: effect of cholecystokinin-octapeptide

This study investigated the effects of cholecystokinin-octapeptide (CCK-8) on pancreatic juice flow and its contents, and on cytosolic calcium (Ca2+) and magnesium (Mg2+) levels in streptozotocin (STZ)-induced diabetic rats compared to healthy age-matched controls. Animals were rendered diabetic by a single injection of STZ (60 mg kg(-1), I.P.). Age-matched control rats obtained an equivalent volume of citrate buffer. Seven weeks later, animals were either anaesthetised (1 g kg(-1) urethane; IP) for the measurement of pancreatic juice flow or humanely killed and the pancreas isolated for the measurements of cytosolic Ca2+ and Mg2+ levels. Non-fasting blood glucose levels in control and diabetic rats were 92.40 +/- 2.42 mg dl(-1) (n = 44) and >500 mg dl(-1) (n = 27), respectively. Resting (basal) pancreatic juice flow in control and diabetic anaesthetised rats was 0.56 +/- 0.05 ul min(-1) (n = 10) and 1.28 +/- 0.16 ul min(-1) (n = 8). CCK-8 infusion resulted in a significant (p < 0.05) increase in pancreatic juice flow in control animals compared to a much larger increase in diabetic rats. In contrast, CCK-8 evoked significant (p < 0.05) increases in protein output and amylase secretion in control rats compared to much reduced responses in diabetic animals. Basal [Ca2+]i in control and diabetic fura-2-loaded acinar cells was 109.40 +/- 15.41 nM (n = 15) and 130.62 +/- 17.66 nM (n = 8), respectively. CCK-8 (10(-8)M) induced a peak response of 436.55 +/- 36.54 nM (n = 15) and 409.31 +/- 34.64 nM (n = 8) in control and diabetic cells, respectively. Basal [Mg2+]i in control and diabetic magfura-2-loaded acinar cells was 0.96 +/- 0.06 nM (n = 18) and 0.86 +/- 0.04 nM (n = 10). In the presence of CCK-8 (10(-8)) [Mg2+]i in control and diabetic cells was 0.80 +/- 0.05 nM (n = 18) and 0.60 +/- 0.02 nM (n = 10), respectively. The results indicate that diabetes-induced pancreatic insufficiency may be associated with derangements in cellular Ca2+ and Mg2+ homeostasis.

Under pressure: choledochal malformation manometry

PURPOSE

The cause of choledochal (cystic or fusiform) malformation is not known. A favoured hypothesis suggests that abnormal reflux of activated pancreatic secretions via a common pancreatobiliary channel may initiate mucosal injury and mural weakness leading to bile duct dilatation, at normal intraduct pressures. However, bile duct pressures in both normal or disease states are not known in such children.

METHODS

Intraoperative choledochal pressure (CP) measurements were made before any other manipulation. Bile was cultured and its amylase content measured. Biochemical liver function (bilirubin, aspartate aminotransferase, gamma-glutamyl transpeptidase, and alkaline phosphatase) was measured. Data were quoted as median (interquartile range). Statistical tests were parametric, where appropriate, and P = .05 was regarded as significant.

RESULTS

Twenty-five children (age 2.5 [1.25-5.91] years) with choledochal (cystic [n = 13] and fusiform [n = 12]) malformation coming to surgery were studied. Median CP was 13 (8.5-17) mm Hg. Median bile amylase was 6722 (241-18,000) IU/L. Choledochal pressure inversely correlated with bile amylase (r = -0.60, P = .001), serum aspartate aminotransferase (r = 0.46, P = .01), and log gamma-glutamyl transpeptidase (r = 0.4, P = .04) but not with bilirubin (P = .11), alkaline phosphatase (P = .20), or age (P = .11). No difference in CP, bile amylase, or liver biochemistry could be identified between the 2 biliary phenotypes. All bile cultures were sterile.

CONCLUSIONS

Increased CP is inversely related to the level of bile amylase (and hence degree of the functional common channel). This suggests that obstructive stenosis at the level of the pancreatobiliary junction (but not the ampulla) may be a causal factor in a proportion of choledochal malformations.

Opposite effects of antidepressants on unstimulated and stimulated salivary flow

In this study, effects on both stimulated and non-stimulated salivary flow as well as salivary components of different antidepressant drugs were compared. Rats received imipramine (IMI; 10mg/ml), fluoxetine (FLU; 20 mg/ml) or moclobemide (MOC; 30 mg/ml) by gavage. The drugs were administered 24, 5 and 1 h before saliva collection (sub-acute treatment) or as a once a day treatment for 14 days (chronic treatment). Animals were sedated with thiopental and saliva was collected using pre-weighed cotton balls inserted in the mouth for 1 min before and after pilocarpine stimulus. Pilocarpine-stimulated saliva was also collected for biochemical assays of total proteins, amylase, phosphate and calcium, performed through automated colorimetric methods. Non-stimulated salivary flow was decreased by sub-acute IMI 10 mg/kg treatment. Pilocarpine-stimulated salivary flow was significantly increased by acute treatments with IMI, FLU and MOC in comparison to the control group. The same opposite pattern of effects on non-stimulated and pilocarpine-stimulated salivation was seen after chronic treatment with the antidepressants. Increased levels of calcium following sub-acute treatment with IMI and after prolonged treatment with FLU and MOC were detected. In the assayed samples, phosphate was found to be increased following chronic treatment with FLU or MOC. These results may explain the discrepant effects of the antidepressants on salivation described in pre-clinical and clinical studies.

Impact of a common CV evaluation scheme on overall laboratory performance: 8-year experience of a large national proficiency testing program in Japan

In proficiency testing (PT), it is difficult to set rational criteria for determining target values and allowable limits. In Japan, the largest national PT program has for the past 8years used an evaluation scheme based on a “common coefficient of variation” (cCV) to overcome this difficulty. The cCV, the average within-method variation, is derived by one-way analysis of variance from data of peer groups after excluding those with large variations. A unit interval used for grading participants is obtained by multiplying the cCV by the peer-group mean which is computed using an iterative method featuring repeated removal of a large portion of the tails of the distribution and reinflation of the standard deviation (SD) to compensate for the trimming. The evaluation scheme gives a relatively better grade to those participants in peer groups with small CVs, compared to use of individual peer-group CVs. The scheme has expedited the transition to more reproducible methods, resulting in a notable overall improvement in laboratory performance. The cCV evaluation scheme is uniformly applicable to any analyte measured quantitatively. The iterative method, an integral part of the scheme, effectively precludes bias in the evaluation.

Characterization of the TGN exit routes in AtT20 cells using pancreatic amylase and serum albumin

The AtT20 pituitary cell is the one that was originally used to define the pathways taken by secretory proteins in mammalian cells. It possesses two secretory pathways, the constitutive for immediate secretion and the regulated for accumulation and release under hormonal stimulation. It is in the regulated pathway, most precisely in the immature granule of the regulated pathway, that proteolytic maturation takes place. A pathway that stems from the regulated one, namely the constitutive-like pathway releases proteins present in immature granules that are not destined for accumulation in mature granules. In AtT20 cells proopiomelanocortin the endogenous precursor of the accumulated adrenocorticotropic hormone, is predominantly secreted in a constitutive manner without proteolytic maturation. In order to better understand by which secretory pathway intact proopiomelanocortin is secreted by a cell line possessing a regulated secretory pathway, it was transfected with rat serum albumin (a marker of constitutive secretory proteins), and pancreatic amylase (a marker of regulated proteins). COS cells were also transfected in order to serve as control of release by the constitutive pathway. It was observed that both the basal and stimulated secretions of albumin and proopiomelanocortin from AtT20 cells are identical. In addition, secretagogue stimulation when POMC is in transit in the trans-Golgi network decreases its constitutive secretion by 50%. It was also observed using cell fractionation and 20 degrees C secretion blocks that albumin and proopiomelanocortin are present in the regulated pathway, presumably in the immature granules, and are secreted by the constitutive-like secretory pathway. These observations show that stimulation can increase sorting into the regulated pathway, and confirm the importance of the constitutive-like secretory pathway in the model AtT20 cell line.

Soluble guanylyl cyclase is localised in the acinar cells and participates in amylase secretion in rat parotid gland

It is well known that the muscarinic cholinergic agonists, carbachol and methacholine, enhance nitric oxide synthase (NOS) activity, and also stimulate salivary secretion. In the present study, we investigated whether salivary secretion by muscarinic cholinergic stimulation is mediated through the NO/cGMP signaling pathway in rat salivary glands. Since NO activates soluble guanylyl cyclase (sGC) and cGMP may function as a mediator, the localisation of sGC was investigated in the salivary glands. sGC was localized in both the acinar and duct cells of the rat parotid and sublingual glands, and localized only in the acinar cells of the submandibular glands. S-Nitroso-glutathione (NO generator; GSNO) and YC-1 (NO-independent sGC activator) stimulated sGC in the cytosol to synthesise cGMP. The combination of GSNO and YC-1 stimulated sGC synergistically. Carbachol, GSNO and YC-1 enhanced amylase release from the rat parotid glands. Amylase release stimulated by carbachol and GSNO was inhibited by addition of the sGC inhibitor, ODQ, and cGMP-dependent protein kinase inhibitor, KT-5823. These results indicate that amylase release may be mediated through the NO/cGMP signaling pathway.

Effect of psychological stress on the salivary cortisol and amylase levels in healthy young adults

OBJECTIVE

Saliva sampling has the advantage that it is non-invasive, making multiple sampling easy and stress free. We examined the effects of psychological stressor and soother on the salivary cortisol and amylase levels in young adults, and compared the characteristics of these parameters.

DESIGN

The subjects completed the trait version of State-Trait Anxiety Inventory (STAI) to assess the predisposition to personal anxiety. The video of corneal transplant surgery was served as the stressor for 15 min. A scenic beauty video viewing was also used as the soother. Unstimulated whole saliva was collected every 3 min throughout the session.

RESULTS

The amylase level was significantly increased just after the beginning of the stressful video viewing, and immediately returned to the pre-stress level just after the end of the video viewing. The cortisol level was also increased, but to a lesser extent compared with that of amylase. The latency time to the peak level for cortisol was longer than that of amylase. The carry-over effect was not observed in the amylase response but was in cortisol. Although the correlation between the amylase level and the STAI score was highly significant, cortisol level did not. In addition, soothing video viewing significantly decreased the amylase level, but did not affect the cortisol level.

CONCLUSION

Salivary amylase level was more significantly increased and reacted more rapidly than cortisol by psychological stressor, suggesting that it is a better index of stress. Furthermore, it is suggested that the enzyme is a soothing or relaxation index.

[Effects of acarbose on amylase tests]

Acarbose is an antidiabetic drug that inhibits alpha-D-glucosidase and alpha-amylase. We have found discrepancies of serum and urine amylase activities (AA) determined with different assay methods using samples collected from diabetes mellitus patients taking acarbose. As a result of our screening test using the urine samples, we found a 22% probability of discrepancy (the differences between the two methods were > or = 10% at AA > or = 100 U/l). We have measured acarbose in five discrepant samples by high-performance liquid chromatography/mass-spectrometry and quantified very low levels (0.36-0.93 micromol/l) of acarbose in three samples of urine. The inhibition of AA was known not only to be caused by acarbose but also its metabolites. We should suppose that the inhibitory effects of its metabolites on amylase measurements are larger than those of acarbose.