Decrease In Amylase Activity Research Articles

Alteration in oxidative stress markers, digestive physiology and gut microbiota of Heteropneustes fossilis and Clarias batrachus exposed to eriochrome black T

Synthetic dyes are the primary cause of water pollution in industrial regions. Azo dyes account for 60–70% of such dyes used in the textile sector due to their numerous beneficial characteristics. Nevertheless, there is a dearth of knowledge regarding the toxicity of Eriochrome Black T (EBT), a widely used azo dye in the textile industry. Therefore, the current study was designed to investigate the effect of EBT exposure on two catfish species, Heteropneustes fossilis and Clarias batrachus. Following 96 h exposure to 1, 10 and 20 mgL−1 of EBT, the MDA content and activities of SOD, CAT and GR exhibited a rising trend. However, as the concentration of EBT increased in both species, GPx showed decreased activity. EBT exposure also altered gut morphometry as well as the three main digestive enzymes activity (increase in lipase and trypsin activity, while decrease in amylase activity). In addition, the exposure of EBT had a significant impact on the gut microbiota of both species. C. batrachus demonstrated the suppression or absence of beneficial gut commensals (Bacillus and Cetobacterium), whereas H. fossilis revealed the proliferation and appearance of beneficial commensal microbes (Bacillus, Bacteroides, Prevotella, and Megashaera). Furthermore, the expansion or absence of these microbial communities indicated that the gut microbiota of both species was involved in dye digestion, immunity and detoxification. Overall, the percent change calculation of all the selected biomarkers, together with gut microbiota analysis, indicates that C. batrachus was more vulnerable to EBT exposure than H. fossilis. The present investigation effectively demonstrated the toxic impact of EBT on fish health by employing oxidative stress markers, digestive enzymes, and the fish gut microbiota as a promising tool for screening the impact of dye exposure on digestive physiology in toxicological research.

Decreased pancreatic amylase activity after acute high-intensity exercise and its effects on post-exercise muscle glycogen recovery.

Our prior results showed that an acute bout of endurance exercise for 6h, but not 1h, decreased pancreatic amylase activity, indicating that acute endurance exercise may affect carbohydrate digestive capacity in an exercise duration-dependent manner. Here, we investigated the effects of acute endurance exercise of different intensities on mouse pancreatic amylase activity. Male C57BL/6J mice performed low- or high-intensity running exercise for 60min at either 10 (Ex-Low group) or 20m/min (Ex-High group). The control group comprised sedentary mice. Immediately after acute exercise, pancreatic amylase activity was significantly decreased in the Ex-High group and not the Ex-Low group in comparison with the control group. To determine whether the decreased amylase activity induced by high-intensity exercise influenced muscle glycogen recovery after exercise, we investigated the rates of muscle glycogen resynthesis in Ex-High group mice administered either oral glucose or starch solution (2.0mg/g body weight) immediately after exercise. The starch-fed mice exhibited significantly lower post-exercise glycogen accumulation rates in the 2-h recovery period compared with the glucose-fed mice. This difference in the glycogen accumulation rate was absent for starch- and glucose-fed mice in the sedentary (no exercise) control group. Furthermore, the plasma glucose AUC during early post-exercise recovery (0-60min) was significantly lower in the starch-fed mice than in the glucose-fed mice. Thus, our findings suggest that acute endurance exercise diminishes the carbohydrate digestive capacity of the pancreas in a manner dependent on exercise intensity, with polysaccharides leading to delayed muscle glycogen recovery after exercise.

Combined effects of pentachlorophenol and nano-TiO2 with different sizes on antioxidant, digestive, and immune responses of the swimming crab Portunus trituberculatus

Marine nano-titanium dioxide (nano-TiO2) and pentachlorophenol (PCP) pollution are escalating concerns in coastal areas. This study investigated the combined effects of continuous exposure to nano-TiO2 (25 nm, 100 nm) and PCP (0, 1, 10 μg/L) for 28 days on the antioxidant, digestive, and immune abilities of the swimming crab Portunus trituberculatus. Compared with the control group, the interaction between nano-TiO2 and PCP was significantly higher than exposure to a single stressor, with a pronounced decrease in amylase activity observed due to the reducing nano-TiO2 particle sizes. Resulting in increased MDA and SOD activity. The expression levels of Toll4, CSP3, and SER genes in crab hemolymph showed perturbations following exposure to nano-TiO2 and PCP. In summary, according to the results of CAT, GPX, PES and AMS enzyme activities, it was concluded that compared to the larger particle size (100 nm), the single stress of nano-TiO2 at a smaller particle size (25 nm) and co-stress with PCP have more significant impacts on P. trituberculatus. However, the potential physiological regulation mechanism of the interaction between these pollutants remains elusive and requires further study.

Mitochondrial malfunction mediates impaired cholinergic Ca2+ signalling and submandibular salivary gland dysfunction in diabetes

Xerostomia (dry-mouth syndrome) is a painful and debilitating condition that frequently occurs in individuals with diabetes and is associated with impaired saliva production and salivary gland hypofunction. Saliva fluid production relies on Ca2+-coupled secretion driven by neurotransmitter stimulation of submandibular acinar cells. Although impairments in intracellular Ca2+ signalling have been reported in various xerostomia models, the specific Ca2+-dependent mechanisms underlying saliva fluid hypofunction in diabetes remain unclear. In this study, we show that diabetic animals exhibit severe xerostomia, evident by reduced saliva flow rate, diminished total protein content, and decreased amylase activity in the saliva secreted by submandibular glands. These impairments remained resistant to exogenous cholinergic stimulation. In submandibular acinar cells, the intracellular Ca2+ signals evoked by cholinergic stimulation were reduced and delayed in diabetes, caused by malfunctioning mitochondria. Upon initiation of cholinergic-evoked Ca2+ signals, mitochondria accumulate higher Ca2+ and fail to redistribute Ca2+ influx and facilitate the store-operated Ca2+ entry effectively. Structural damage to mitochondria was evident in the acinar cells in diabetes. These findings provide insights into the potential targeting of malfunctioning mitochondria for the treatment of diabetic xerostomia as an alternative strategy to the existing pharmacotherapeutic approaches.This article is part of the Special Issue on "Ukrainian Neuroscience"

Also in Crayfish: How Phytase Inclusion Avoids Phytic Acid Effects on Hepatopancreas Enzymes of Redclaw Cherax quadricarinatus

This work aimed to evaluate the effects of dietary phytic acid on the enzymatic activities of the hepatopancreas of the redclaw crayfish, Cherax quadricarinatus. For this purpose, a completely randomized in vitro trial was conducted with three phytic acid levels (0.56, 1.68, and 2.80%) and three phytase doses (0, 250, and 500 PU/kg DM). Solubilized protein, reducing sugars, and soluble phosphorus showed significant responses to the interaction between phytic acid and phytase p < 0.001 . Only the main effects were detected on the released amino acids, in keeping with the main effects of alkaline protease activity, which are negatively affected by phytic acid p < 0.001 and improved by phytase inclusion p < 0.001 . Differences in released reducing sugars were attributed to a reduction in amylase activity by increased levels of phytic acid and not to cellulase activity, where only a negative trend of phytic acid was found p = 0.068 . Phytic acid depresses calcium availability, which would explain the decrease in amylase activity. A 500 PU/kg DM dose improved amino acid, reduced sugars, and phosphorus release. These in vitro results might have in vivo implications for the digestibility of proteins, minerals, and energy. Further investigations are required to determine the chelated calcium effect on redclaw amylase activity, molting, and survival.

Optimizing Acetic Acid Application Strategy Can Effectively Promote the Remediation Performance of Oilseed Sunflower on Cd-Contaminated Soils

Applying exogenous organic acids is an effective method to improve the remediation efficiency of Cd-contaminated soils. To investigate the effects of exogenous acetic acid on Cd forms in rhizosphere soils and phytoremediation performance for Cd-contaminated soils, a potted experiment was performed with oilseed sunflower as the extractive plant. Acetic acid was applied at 1, 2, 3, 4, 5, and 6 mmol/kg at 20, 30, 40, and 50 days after seedling emergence. Soil without acetic acid was used as a control (CK). Emblematic chemical properties and different Cd forms in rhizosphere soils were inspected. Results showed that adding acetic acids improved the biomass of shoot and root; it increased firstly and then decreased with the increase of acetic acid concentrations. For all treatments, acetic acids increased sucrase activity and catalase activity but decreased amylase activity in rhizosphere soils. At 30 or 40 days after seedling emergence, the exchangeable Cd content, Fe-Mn oxide Cd content, and organic Cd content were lower, while the carbonate Cd content was greater. Adding acetic acids improved the removal rate of Cd, and when 1 mmol/kg acetic acid was applied at 40 days after seedling emergence, it was increased by 60%, which was the highest compared to CK. RDA showed that catalase activity, sucrase activity, carbonate Cd, and pH could promote the growth of oilseed sunflower, while organic Cd, Fe-Mn oxide Cd, total Cd, exchangeable Cd, and amylase activity inhibited the growth of oilseed sunflower. These findings suggest that acetic acid can improve the efficiency of phytoremediation in Cd-contaminated soils. In particular, the treatment with 1 mmol/kg acetic acid at 40 days after seedling emergence had the most obvious effect.

Ethanol binge drinking during pregnancy and its effects on salivary glands of offspring rats: oxidative stress, morphometric changes and salivary function impairments

ObjectivesTo investigate the biochemical and morphological effects of ethanol (EtOH) binge drinking during pregnancy on parotid glands (PG), submandibular glands (SMG), and saliva of offspring rats. MethodsPregnant Wistar rats (n = 8) were exposed to EtOH consumption (3 g/kg/day – 20 % w/v) for three consecutive days. The saliva of 40-day-old offspring rats was collected to determine amylase activity and total protein concentration. PG and SMG were collected to performe oxidative biochemistry, morphometric and immunohistochemistry analyses (Student’s t-test, p < .05). ResultsEtOH consumption during pregnancy significantly decreased the total protein concentration and decreased amylase activity. In the PG, the EtOH group showed increased lipid peroxidation and decreased antioxidant capacity against peroxyl. In the SMG, the EtOH group showed increased lipid peroxidation and NOx metabolite levels. PG exposed to EtOH showed a decrease of acini, ducts, and total parenchymal area. SMG exposed to EtOH showed an increase in the total stromal area. The expression of CK-19 and Vimentin were found not different between groups. ConclusionsFor the first time, a three-day EtOH binge-drinking protocol during pregnancy is associated with oxidative stress and morphometric alterations in the salivary glands of offspring rats and with the functional reduction of the main salivary enzyme (amylase). Clinical relevance: EtOH consumption during pregnancy altered the morphology and physiology of the salivary glands of offspring rats.

Secrets, puzzles and mysteries of macroamylasemia

Physiological features of amylase synthesis and excretion are considered in the article, presence of other sources of amylase synthesis different from pancreas and salivary glands is emphasized. Definitions of hyperenzymemia and macroamylasemia (MAE) are given. MAE is a state characterized by presence of circulating complexes of normal serum amylase with protein or carbohydrates in blood. There are 3 types of MAE: first — classical (constant hyperamylasemia, decreased amylase level in urine, high blood concentration of macroamylase complexes); second — hyperamylasemia with slightly decreased amylase activity in urine, macroamylase/normal amylase ratio is less than in the first type; third — normal blood and urine amylase activity, low macroamylase/normal amylase ratio. Pathogenesis is explained by connection of blood amylase and acute phase protein in different inflammatory, infectious diseases, malabsorption. MAE clinical manifestations could be absent, sometimes abdominal pain is possible. Hyperamylasemia and reduced urine amylase activity are typical. MAE diagnostics means determination of macroamylase complexes in blood (chromatography, calculation of the clearance ratio of amylase and creatinine). The article presents clinical cases describing extra-pancreatic MAE in women with malignant ovarian lesions. The question of expediency of thorough diagnostic examination in asymptomatic MAE is raised, which may turn out to be a symptom of cancer. The lack of specific treatment for MAE is emphasized.

Reduced salivary amylase activity in metabolic syndrome patients with obesity could be improved by treatment with a dipeptidyl peptidase IV inhibitor

The present study is to investigate the salivary gland function of metabolic syndrome (MetS) patients, as indicated by salivary flow rate, amylase activity, and salivary oxidative stress, by measuring MDA level. One hundred and eighty-one MetS patients from Maharaj Nakorn Chiang Mai Hospital were enrolled onto this study. The metabolic parameters of each patient were collected and evaluated. Unstimulated saliva was also collected for 5min. Salivary gland functions, including salivary flow rate, amylase activity, and salivary MDA levels, were investigated. High levels of triglycerides, high-density lipoprotein, blood pressure, and waist circumference in MetS patients did not show a correlation with altered salivary gland function. However, a decrease in salivary flow rate was observed in MetS patients with hyperglycemia. In addition, decreased amylase activity was found in MetS patients with obesity (BMI ≥ 23kg/m2). Salivary amylase activity of MetS patients treated with dipeptidyl peptidase IV (DPP-IV) inhibitor was significantly greater than that observed in MetS patients without a DPP-IV inhibitor. Moreover, the salivary amylase activity in MetS patients was found to be independently positively correlated with DPP-IV inhibitor therapy (r = 0.708, p < 0.01). These findings suggest that obesity and hyperglycemia in MetS patients were associated with the impairment of salivary glands. Treatment with a DPP-IV inhibitor was found to exert beneficial effects on the salivary gland. This study demonstrated the impairment of salivary glands of MetS patients and the beneficial effect of DPP-IV inhibitor treatment in the salivary glands.

Chamomile and oregano extracts synergistically exhibit antihyperglycemic, antihyperlipidemic, and renal protective effects in alloxan-induced diabetic rats.

The bio-activities of separate Matricaria chamomilla (chamomile) and Origanum vulgare (oregano) are well studied; however, the combined effects of both natural products in animal diabetic models are not well characterized. In this study, alloxan-induced male albino rats were treated with single dose aqueous suspension of chamomile or oregano at dose level of either 150 or 300 mg/kg body mass or as equal parts as combination by stomach tube for 6 weeks. After treatment, blood samples were assessed for diabetic, renal, and lipid profiles. Insulin, amylase activity, and diabetic renal apoptosis were further evaluated. Treatment with higher dose of the extracts (300 mg/kg) as individual or as mixture of low doses (150 mg/kg of both the extracts) had significant mass gain, hypoglycemic effect (p ≤ 0.05) with decreased amylase activity and increased serum insulin levels. Restoration of renal profile, lipid profile with increase in HDL-c (p ≤ 0.05) along with reversal of pro-apoptotic Bax and anti-apoptotic Bcl-2 were well observed with 300 mg/kg mixture, showing synergistic activity of the extracts compared with individual low dose of 150 mg/kg. Collectively, our results indicate that combination of chamomile and oregano extracts will form a new class of drugs to treat diabetic complications.

Evaluation of the supplementation of a feed additive as a potential protector against the adverse effects of 2.5 ppm T-2 toxin on growing broiler chickens

ABSTRACT A trial was conducted to evaluate a feed additive containing epoxidase activity from a bacterium (Mycofix-S) as a potential protection against the adverse effects of 2.5 ppm dietary T-2 toxin in male growing broiler chickens. A total of 144 one-day-old Ross 308 male chicks were individually wing-banded and allotted into each of the four experimental groups. Group 1: negative control, no T-2 toxin or additive; group 2: Mycofix-S, 2.5 g/kg; group 3: positive control, 2.5 ppm T-2 toxin; group 4: 2.5 ppm T-2 toxin + 2.5 g/kg Mycofix-S. Feed and water were provided ad libitum for 28 days (days 1 to 28 of age). Each experimental treatment was replicated 6 times, with 6 birds per replicate pen. Response variables included performance parameters, serum activity of alkaline phosphatase (ALP) and amylase, relative weight of selected organs and histology of the upper digestive system. T-2 toxin at 2.5 ppm significantly (P = 0.016) decreased the 28-day body weight gain and cumulative feed intake without affecting feed conversion. The feed additive counteracted these adverse effects. Serum enzyme activities were not significantly (P&gt;0.05) affected for the four experimental groups but when data from the groups receiving T-2 toxin was pooled and compared against the pooled data from groups without the toxin a significant decrease in amylase activity was observed in chickens receiving T-2 toxin. The histological examination of the upper digestive system revealed lesions in mouth, esophagus, proventriculus, gizzard and duodenum in the chickens fed T-2 toxin without the additive. Chickens fed T-2 toxin plus the additive showed lesions in the same tissues except in the duodenum. The results of the present study show that the addition of 2.5 g/kg of the feed additive tested protects against adverse effects on performance and also the integrity of the duodenal mucosa.

Effect of Selenium Supplementation on Serum Amylase, Lactate Dehydrogenase and Alkaline Phosphatase Activities in Rats Exposed to Cadmium or Lead

Abstract The purpose of the study was to assess the effect of selenium supplementation on serum amylase, lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) activities in rats, during subacute exposure to toxic doses of cadmium or lead through the drinking water. The experimental groups (n=6) were: Control, Se (Se+4: 0,2 mg/l), Cd (Cd+2: 150 mg/l), Pb (Pb+2: 300 mg/l), Cd+Se (Cd+2: 150 mg/l; Se+4: 0,2 mg/l) and Pb+Se (Pb+2: 300 mg/l; Se+4: 0,2 mg/l). The animals were sacrificed after 56 days. Amylase, LDH and ALP activities were determined from serum. Se and Pb treatments caused an increase in amylase and LDH activities, when compared to Control group while Cd caused an increase in amylase activity and a decrease in LDH and ALP activities. Cd+Se caused a decrease in amylase activity and an increase in LDH activity, when compared to Cd. Pb+Se caused a decrease in amylase activity in comparison to lead. Selenium supplementation alleviated cadmium or lead induced changes in serum amylase activity. Selenium, coadministered with cadmium, caused a marked increase in serum LDH activity, when compared to cadmium alone or Control group while practically it had no effect on lead induced changes in LDH activity. Cadmium and lead induced disturbances in serum ALP activity were not influenced by selenium supplementation.

Partial Purification of Amylase from the Culture Filtrates of Aspergillus flavus Grown on Cassava Peels

Amylase from a Cassava peel culture of Aspergillus flavus was partially purified by Ammonium Sulphate precipitation as well as dialysis. The dialysed 60% (NH4)2 SO4 precipitated enzyme had an activity of 1.087 mg T.R.S released/ min/mg protein which was two folds of the activity of the crude culture filtrate. Hydrogen ion concentration as well as temperature had profound influence on enzyme activity of the partially purified enzyme while Amylase activity increased progressively as pH was increased from 3 to 7 reaching a maximum of 1.68 mg T.R.S released/min/mg/protein at PH 7.0. A rapid decrease in amylase activity was observed as pH was increased from 7 to 9 while the amylase activity increased with increase in temperature from 300C to 450C and reached a maximum of 1.15 mg T.R.S. released/min/mg/protein at 450C. Subsequent increase in temperature resulted into decrease in activity of the amylase enzyme.

Rhythmic oscillations of α-amylase protein and its enzymatic activity levels in Drosophila melanogaster (Diptera: Drosophilidae)

In this report, we show that α-amylase activity is rhythmic in the wild-type fruit fly Drosophila melanogaster, and that this rhythm exhibits the properties of a clock output. Moreover, the rhythm of amylase activity is accompanied by fluctuations in the Amy protein level under 12L : 12D conditions. A strong sexual dimorphism is evident in the oscillations of Amy protein and enzymatic activity. Under light : dark (LD) conditions on the control diet, CantonS wild-type Drosophila melanogaster exhibit a bimodal rhythm of amylase activity, particularly of the AmyD3 (Amy3) isoform, with morning and evening peaks. Under these conditions, Amy protein levels also oscillate significantly, again more strongly for the Amy3 isoform than Amy1 (Amy1). A robust oscillation of Amy3 and Amy1 activity is also observed under DD conditions for both sexes. In constant light (LL) the rhythms dampen out, particularly in the males. A high level of dietary glucose causes an overall decrease in the amplitudes of the rhythmic oscillations of amylase activity, but the processes are nevertheless rhythmic, with peak activities at Zt8 for the females, and at Zt0 for the males in LD. In constant darkness (DD) the rhythms are maintained. Mutants lacking a functioning oscillator, per01, exhibit a slight photoperiodicity in LD, with a decrease in amylase activity in both males and females during the late night in LD, but no rhythmic oscillations in DD.

The effects of deltamethrin on some serum biochemical parameters in mice

Sixty white male mice were used in this study. Three groups, each comprising 20 mice were established. The control group (Group 1) was provided ad libitum pellet feed. On the other hand, the experimental groups, namely, Groups 2 and 3 were given pellet feed containing deltamethrin throughout the day, so that the animals were administered doses of 7.5 and 30 mg/kg/body weight/day, respectively. Blood samples were collected from all groups on the 15th, 30th, 45th, and 60th days of the experiment for measurement of serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), alcaline phosphatase (ALP), amylase and cholinesterase activities, and levels of glucose, urea, creatinine, triglyceride, cholesterol, calcium, phosphor, sodium, potassium, and chloride. According to data obtained, on the 15th day of the study, compared to the control group, statistically significant increase in urea, cholesterol, ALP, cholinesterase, calcium, and potassium levels/activities, and significant decrease in SGOT activity and chloride levels in Group 2, and significant increase in cholesterol, ALP, cholinesterase, calcium, potassium and chloride levels/activities in Group 3, and significant decrease in SGOT activity in Group 3 were determined. On the 30th day of the study, in comparison to the control group, triglyceride and cholesterol levels and ALP activity were determined to be significantly increased in the Group 2, whereas SGOT activity were significantly reduced in Group 2, and triglyceride and cholesterol levels were demonstrated to be significantly increased and SGOT activity was significantly reduced in Group 3. On the 45th day of the study, compared to the controls, significant increase in cholesterol and sodium levels, and significant decrease in triglyceride levels and ALP activity in Group 2, significant increase in creatinine, cholesterol and sodium levels and cholinesterase activity, and significant decrease in glucose, SGPT, ALP and phosphor levels/activities were detected in Group 3. On the 60th day, in other words, in the last period of the study, ALP activity, and triglyceride, calcium, and phosphor levels were determined to be significantly increased and significant decrease in amylase activity in Group 2. Furthermore, significant increase in triglyceride, ALP, amylase, calcium, phosphor, and potassium levels/activities, and significant decrease in glucose and creatinine levels were observed in Group 3. However no correlation was determined to exist between the changes were found to be statistically significant, and the administration dose and duration of deltamethrin in all periods and groups.

Amylase activity in honey bee hypopharyngeal glands reduced by RNA interference

SUMMARYDouble-stranded RNA (dsRNA) has been found to interfere with gene expression in various species, a phenomenon known as RNA interference (RNAi). We show here that RNAi is effective in reducing gene expression in the adult honey bee (Apis mellifera). A 1175 bp fragment of the hypopharyngeal amylase gene from the honey bee was cloned into a modified pGEM-5Zf(+) vector. The gene fragment was inserted between two opposing T7 promotors, thus enabling expression of dsRNA specific for the amylase gene when the plasmid was grown in an Escherichia coli strain expressing T7 RNA polymerase. This dsRNA was introduced into the haemolymph of forager honey bees by intra-abdominal injection and the effects on amylase activity in the hypopharyngeal glands of those bees examined. Compared to controls, injection of amylase gene dsRNA produced a significant decrease in amylase activity of 27.5% 3 days post-injection (P = 0.001). An experiment using radiolabelling to follow the fate of the dsRNA, revealed that most of the radioactive RNA was lost from the haemolymph within 24 h, probably sequestered into cells. In this experiment, bees injected with amylase gene dsRNA showed a reduction of 80% of amylase activity 24 h post-injection (P = 0.001). This indicates that the maximum effect of the amylase gene dsRNA in bees is probably greater than demonstrated in our initial experiment, and that the effect is short-lived. Here we demonstrate that RNAi is effective in reducing gene expression in Hymenoptera in distant organs following intra-abdominal injection of adult bees.

Dialysis with icodextrin interferes with measurement of serum alpha-amylase activity.

The glucose polymer icodextrin has gained a widespread use in peritoneal dialysis especially in patients with low ultrafiltration and high peritoneal transport properties. In patients using a once-daily exchange with icodextrin, a decreased serum amylase activity has been reported. We explored the potential underlying mechanisms of this effect. Using standard chromolytic methods, serum amylase activity was measured in blood samples from 11 patients on icodextrin treatment and from 11 patients on conventional glucose treatment. Samples were additionally supplemented with alpha-amylase and unused icodextrin dialysis fluid. Potential complex formation between icodextrin and alpha-amylase was studied by SDS-gel electrophoresis with protein silver staining and fluorophore-assisted carbohydrate staining with the AMAC (FACE) method, which provides oligosaccharide labelling. Lipase activity was measured in parallel in all samples by two standard methods. Amylase activity was reduced by 90% in serum from patients using icodextrin for the long dwell (15.9+/-10.9 U/l) vs patients using standard glucose (157.1+/-23.7 U/l; P<0.001). Addition of icodextrin to serum samples from patients using conventional glucose solutions induced a dose-dependent decrease in amylase activity. The assay results indicated a substrate competition between ET7-G7PNP and icodextrin. AMAC fluorophore staining of icodextrin and subsequent gel electrophoresis failed to demonstrate complex formation between icodextrin and alpha-amylase. Unlike the amylase findings, icodextrin did not affect lipase activity. The present findings indicate that icodextrin competitively interacts as a substrate in the amylase assay. In support of this, fluorophore-assisted oligosaccharide electrophoresis on SDS gel failed to reveal the formation of an 'amylase/icodextrin complex'. Lipase measurement should provide an alternative and unconfounded method for diagnosing pancreatitis in icodextrin patients.

Immunoglobulin A secretion into pancreatic juice as a novel marker of local immune defense and exocrine pancreatic function.

The importance of secretory immunoglobulin A (IgA) of local immune defense in the gastrointestinal tract has gained increasing acceptance. Bacterial contamination is a major factor related to mortality in acute pancreatitis. However, very little is known about IgA in pancreatic juice. Pure pancreatic juice was collected from 40 patients undergoing pancreatoduodenectomy. The patients were divided into three groups according to the degree of preoperative pancreatic duct obstruction, as follows: normal, narrowed, and obstructed. IgA concentration, amylase activity, and daily volume of pancreatic juice were measured. Daily IgA secretion into pancreatic juice was constant during the early period after the operation. The concentration of IgA in the control group was 5 +/- 0.8 microg/ml, and IgA daily secretion was 1.2 +/- 0.2 mg/day. Pancreatic duct obstruction resulted in a marked decrease in both amylase and pancreatic juice secretion. The concentration of IgA, however, was markedly increased in the narrowed group (11.1 +/- 2.4 microg/ml) and the obstructed group (32.5 +/- 5.4 microg/ml). The concentration of amylase increased with the increase in pancreatic juice. Conversely, the concentration of IgA increased with the decrease in volume of pancreatic juice. Similarly, the increased in IgA concentrations positively correlated with the decrease in amylase activity. In conclusion, the mechanisms that modulate IgA secretion in the human pancreas are essentially different from those that modulate digestive enzyme and fluid secretion. IgA in pancreatic juice may play an important role in pathological conditions such as pancreatic duct obstruction. As such, the measurement of IgA in pancreatic juice may potentially be used as a new marker of local immune defense and exocrine pancreatic function.

Phenotypic Modulation of Hamster Acinar Cells by Culture in Collagen Matrix

The aim of this study was to assess the effect of different culture conditions on the survival and morphological phenotype of cultured acinar cells. Acinar fragments isolated from hamster pancreas were embedded in rat-tail collagen. Four groups were established: Medium 1—5% NuSerum + basic medium (basic medium = DMEM/F12 supplemented with dexamethasone, 3-isobutyl-2-methylxanthine, and antibiotics); Medium 2—10% NuSerum + basic medium. Medium 3—Medium 2 supplemented with epidermal growth factor and cholera toxin; and Medium 4:—Medium 3 supplemented with soybean trypsin inhibitor. Freshly isolated acinar cells were retrieved morphologically intact. In Medium 1, more than 80% of cells retained a normal histological appearance at 34 days in culture. Immunostaining for amylase was observed at the apical pole of the cells. The remaining cells showed variable degrees of degeneration. In Medium 2, approximately 50% of acinar cells appeared normal at 34 days in culture, while the remainder were severely degenerated. A few cystic structures were also observed. Positive immunostaining for amylase was limited to the cells with a normal histological appearance. The cells grown in Media 3 and 4 had similar courses of morphological changes. After 8 days in culture, most acinar fragments disappeared and were replaced by cystic structures, lined by a single layer of cuboidal cells. Some amylase-positive immunoreactive cells were integral components of the cystic wall. Cellular amylase activity was a function of the different culture media, a more rapid decrease in amylase activity being observed in Media 3 and 4. Uptake of [3H]thymidine did not show any significant differences between the media. It was also found that the ductlike cells cultured in Medium 4 had a limited capacity to redifferentiate into acinar cells. This study shows that the acinar cell phenotype can be maintainedin vitrofor more than 1 month. This study also suggests that ductal-like epithelial structures arise from transformation of acinar cells.

An improved procedure for the recovery of pancreatic enzymes with enhanced activity

Pancreatic enzymes were recovered with enhanced activity by a newly designed extraction process. The protease activity was increased to the extent of 65% by using MES buffer, 64mM and duodenum enzyme extracts containing enterokinase at autolysis stage. The decrease in amylase activity due presumably to proteolytic degradation was effectively prevented by treating the enzyme solution with calcium prior to the autolysis.