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PubMed1979

Effects of adrenergic agonists on the oxygen uptake and amylase output in rat submandibular gland slices.

Oxygen uptake and amylase output in rat submandibular gland slices were measured by utilizing adrenergic agonists. Adrenaline, noradrenaline and isoproterenol significantly stimulated the oxygen uptake and amylase output. In the presence of propranolol or phenoxybenzamine, adrenaline-stimulated oxygen uptake was obviously blocked. Adrenaline-stimulated amylase output was inhibited by propranolol, but was not inhibited by phenoxybenzamine. The increase in oxygen uptake by nornol-stimulated oxygen uptake and amylase output were strongly inhibited by propranolol. The oxygen uptake due to isoproterenol was little affected by phenoxybenzamine. These results suggest that the increase in oxygen uptake seen with adrenergic agonists is mediated by both alpha- and beta-receptors, and that the amylase output is evoked through the stimulation of beta-receptors.

Adrenergic Agonists↗
PubMed1992

Suppression of alpha-amylase gene expression by antisense oligodeoxynucleotide in barley cultured aleurone layers.

Antisense oligodeoxynucleotides (ODNs) have been applied to regulate gene expression using cell-free media or animal cells. Here we demonstrate the specific inhibition of barley alpha-amylase gene expression by synthetic antisense ODNs. In a cell free system using wheat-germ extracts, 5 microM of a 20-mer antisense ODN prevented the synthesis of the polypeptide corresponding to the predetermined length of alpha-amylase translated in vitro, whereas there was no effect on other protein synthesis. Furthermore, in cultured aleurone cells, alpha-amylase activity was efficiently decreased by addition of ODNs. At the concentrations higher than 5 microM, antisense ODN inhibited alpha-amylase gene expression almost completely. These results imply that ODN could transport into the cultured aleurone cells crossing the cell membrane, and regulate specific gene expression. This simple model system could be applicable not only for the analysis of the alpha-amylase multigene family in barley but also for studying functions of cryptic genes in higher plant.

Base Sequence↗
PubMed1992

Maturation of an NH2-terminally extended thermostable alpha-amylase in Bacillus subtilis: a possible mechanism examined by in vitro experiments.

An artificially inserted extra peptide (21 amino acid peptide) between the B. subtilis alpha-amylase signal peptide and the mature thermostable alpha-amylase was completely cleaved by B. subtilis alkaline protease in vitro. The cleavage to form a mature enzyme was observed between pH 7.5 and 10, but not between pH 6.0 and 6.5, although a similar protease activity toward Azocall was observed between pH 6.0 and 7.5. To analyze the effects of pH on the cleavage, CD spectra at pH 6, 8, and 11 of the NH2-terminally extended thermostable alpha-amylase were analyzed and the results were compared with those of the mature form of the alpha-amylase. It is suggested that the cleavage of the NH2-terminally extended peptide is controlled by the secondary and tertiary structure of the precursor enzyme. Similar cleavage of different NH2-terminally extended peptides by the alkaline protease was also found in other hybrid thermostable alpha-amylases obtained.

Amino Acid Sequence↗
PubMed1993

A neopullulanase-type alpha-amylase gene from Thermoactinomyces vulgaris R-47.

Shimizu et al. and ourselves have reported some enzymatic properties of an alpha-amylase from Thermoactinomyces vulgaris R-47 that hydrolyzed pullulan to produce panose [M. Shimizu et al., Agric. Biol. Chem., 42, 1681-1688 (1978); Y. Sakano et al., Agric. Biol. Chem., 46, 1121-1129 (1982)]. In this study, we cloned a gene for an alpha-amylase, which was different from the one mentioned above but also hydrolyzed pullulan to produce panose, from T. vulgaris R-47, and analyzed the entire primary structure of the gene. We designated the previously reported enzyme as T. vulgaris alpha-amylase I (TVA I), and this novel enzyme as T. vulgaris alpha-amylase II (TVA II). The nucleotide sequence had an open reading frame of 1755 base pairs corresponding to a protein of 585 amino acid residues. Although this novel alpha-amylase, TVA II, hydrolyzed both pullulan and starch, the ratio of pullulan-hydrolyzing activity to starch-hydrolyzing activity of the enzyme was higher than that of TVA I, and the primary structure of the enzyme resembled neopullulanase, which scarcely hydrolyzed starch, rather than that of TVA I.

Amino Acid Sequence↗
PubMed2004

Proteomic identification of alpha-amylase isoforms encoded by RAmy3B/3C from germinating rice seeds.

We isolated and identified 10 alpha-amylase isoforms by using beta-cyclodextrin Sepharose affinity column chromatography and two-dimensional polyacrylamide gel electrophoresis from germinating rice (Oryza sativa L.) seeds. Immunoblots with anti-alpha-amylase I-1 and II-4 antibodies indicated that 8 isoforms in 10 are distinguishable from alpha-amylase I-1 and II-4. Peptide mass fingerprinting analysis showed that there exist novel isoforms encoded by RAmy3B and RAmy3C genes. The optimum temperature for enzyme reaction of the RAmy3B and RAmy3C coding isoforms resembled that of alpha-amylase isoform II-4 (RAmy3D). Furthermore, complex protein polymorphism resulted from a single alpha-amylase gene was found to occur not only in RAmy3D, but also in RAmy3B.

Amino Acid Sequence↗
PubMed1990

An in vitro evaluation of adrenergic action on rat pancreatic amylase secretion: lack of stimulatory effect.

To assess direct evidence of adrenergic stimulation in pancreatic amylase secretion, effects of catecholamines on amylase release and intracellular cyclic AMP accumulation were examined with rat dispersed pancreatic acini. We first carried out control studies with CCK-8 and carbamylcholine to evaluate the usefulness of the material for the examination of amylase secretion, and examined VIP-induced cyclic AMP accumulation to assess the agonist evoked intracellular response. As a result, significant effects of CCK-8, carbamylcholine and VIP were observed, which confirmed that dispersed pancreatic acini used in this study were useful in examining exocrine pancreatic secretion. However, catecholamines failed to stimulate amylase release from pancreatic acini, although a significant increase in intracellular cyclic AMP accumulation was observed. Thus the present study strongly suggests that direct involvement of catecholamine is unlikely in pancreatic amylase secretion, in contrast to results reported previously.

1-Methyl-3-isobutylxanthine↗
PubMed1992

The embryo pancreas is a source of increased yolk amylase in the fertilized eggs of domestic fowls.

The amylases were studied in the yolk of fertilized eggs and in the pancreases of the embryos of domestic fowls. The amylase activity in the yolk increased markedly from 13 days of incubation until hatching, but the activity decreased when the embryos were taken out of the eggs. The isoamylases in the yolk and in the pancreas of the embryo were identical electrophoretically. The amylase occurs mainly in the pancreas of the embryo. We think that the increase in amylase activity in the yolk of fertilized eggs during incubation depends upon the accumulation of pancreatic amylase synthesized by the developing embryo in the egg.

Amylases↗
PubMed2002

Role of mitochondrial NADH shuttle system in acute amylase secretion by acetylcholine from mouse pancreatic acinar cells.

Using the mice that lack mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH), a rate limiting enzyme of the glycerol-phosphate NADH shuttle, we investigated the role of the NADH shuttle system in amylase secretion in response to acetylcholine (ACh) in pancreatic acinar cells. The pancreatic acinar cells of mGPDH-deficient mice were not different in histology and immunohistochemistry from those of wild-type mice. In both types of pancreatic acinar cells from wild-type and mGPDH-deficient mice, ACh similarly potentiated amylase secretion, measured in 30 minutes after the ACh stimulation. A 30 minutes pre-treatment of wild-type cells with aminooxyacetate (AOA), an inhibitor of aspartate aminotransferases of the malate-aspartate NADH shuttle, did not change the rate of ACh-induced amylase secretion, measured in the following 30 minutes. In also mGPDH-deficient cells treated with AOA, thus in this situation all mitochondrial NADH shuttles being dysfunctioning, ACh induced amylase release in a similar amount to that in AOA-untreated cells. The basal levels of intracellular Ca2+ concentration ([Ca2+]i), the ACh-stimulated levels of [Ca2+]i and Ca2+ oscillation patterns in response to ACh were similar in wild-type and mGPDH-deficient cells, and the AOA-treatment did not affect these [Ca2+]i responses. The levels of intracellular concentration of ATP before and during stimulation with ACh were similar in wild-type and mGPDH-defficient cells. In only AOA-treated mGPDH-deficient cells, the level of ATP decreased after the ACh stimulation. These results suggest that acute response of amylase secretion to ACh from mouse pancreatic acinar cells does not require simultaneous functioning of the mitochondrial NADH shuttle system, although the supply of intracellular ATP decreases during the ACh stimulation.

Acetylcholine↗
PubMed1992

A case of amylase-producing lung cancer.

A case of lung cancer with hyperamylasemia was studied. Small cell carcinoma was diagnosed histologically. The salivary gland and pancreas had no clinical involvement in the hyperamylasemia. Saliva-type amylase was dominant as observed from amylase isozyme patterns in the serum and tumorous tissue. Levels of amylase were higher in tumorous tissue than in normal lung tissue. Immunohistochemical study showed amylase localized in tumor cells. Observation of the ultrastructure revealed electron-dense granules in the cytoplasm of the tumor cells. Findings suggested that amylase was being produced by the lung cancer in this case.

Amylases↗
PubMed1983

Dynamic analysis of secretagogue-induced amylase secretion from rat pancreatic acini studied by perifusion system.

A perifusion system was applied for the study on stimulus-enzyme secretion coupling in dispersed pancreatic acini. The system is highly simple, preserves the acini up to more than 3 hr, and makes feasible clear-cut examination on the time course of enzyme secretion caused by secretagogues. Caerulein (10(-9) M) and carbamylcholine (10(-5) M) caused a biphasic amylase secretory pattern consisting of an initial burst secretion and a sustained one. Caerulein induced a persistent amylase release even after cessation of the stimulation, while carbamylcholine-stimulated amylase release returned to basal levels. Atropine inhibited completely carbamylcholine-stimulated amylase release and the successive stimulation by caerulein evoked the amylase secretion with a decreased initial burst secretion. In calcium free medium, caerulein and carbamylcholine induced only a slight secretion, particularly in the sustained secretion phase and a gradual increase occurred with the addition of calcium.

Amylases↗
PubMed1988

Evidence for the direct action of gastrin-releasing peptide (GRP) on amylase secretion from rat pancreatic acini: an assessment using a perifusion system.

We examined the effects of porcine gastrin-releasing peptide (GRP) on exocrine secretion from dispersed rat pancreatic acini using a perifusion system. GRP stimulated amylase secretion, in a dose-dependent manner in the range of 10(-10)-10(-5) M. The submaximum response was observed at 10(-8) M. Stimulation with 10(-8) M GRP caused a biphasic release of amylase. Amylase secretion by GRP stimulation was not affected by the addition of carbachol, dibutyryl cyclic GMP, or atropine. W-7, a calmodulin antagonist, inhibited the amylase secretion induced by GRP. The addition of isobutylmethylxanthine or secretin increased amylase secretion caused by GRP stimulation. These observations suggest that GRP facilitates enzyme secretion by a direct action on pancreatic acini and not through muscarinic and cholecystokinin receptors. The interaction by the Ca2+-calmodulin complex was suggested.

Amylases↗
PubMed2005

Maltose adaptive mutant of heterotrophic marine bacterium, Alteromonas espejiana Bal-31: changes in the growth and the induction of extracellular alpha-amylase.

Growth of the heterotrophic marine bacterium, Alteromonas espejiana Bal-31 was inhibited in the presence of sucrose, maltose and even glucose, but not with starch. Extracellular alpha-amylase was induced with a lag phase of 2 h in the presence of starch. In contrast, cell growth of the S2a mutant was not affected by the addition of maltose, and starch was ineffective in the induction of extracellular alpha-amylase in this mutant. Activity of extracellular alpha-amylase was induced from the S2a mutant with a 4-h lag phase in the presence of maltose, and the high level of enzyme activity was maintained for at least 24 h. Activity of alpha-amylase induced by both wild type starch and S2a mutant maltose cultures were mainly observed in extracellular locations. This activity could be stopped by tetracycline treatment, indicating that enzyme induction was dependant on gene expression and not on enzyme protein secretory mechanisms. Our results showed that the mutation in S2a changed the growth and the modulation of the specific alpha-amylase in response to carbon nutrients.

Adaptation, Physiological↗
PubMed1989

Intravenous injection of caerulein or cholecystokinin increases the parotid-type and pancreatic-type amylase in the serum of rats.

Caerulein and cholecystokinin (CCK) injection (i.v.) into rats caused about a 2.3- and 1.9-fold increase in serum amylase activity within 2 h, respectively. The increase of amylase activity in the serum caused by pilocarpine or isoproterenol injection (i.p.) was only of parotid-type amylase. Caerulein or CCK markedly increased pancreatic-type amylase, and significantly increased parotid-type amylase in the serum.

Amylases↗
PubMed1981

Insulin and its secretagogues activate Ca2+-dependent phosphatidylinositol breakdown and amylase secretion in rat pancreas in vitro.

We studied the effects of insulin and insulin secretagogues on pancreatic phospholipids and the release of amylase from pancreatic fragments incubated in vitro. Insulin provoked rapid, dose-related increases in amylase release, and these were accompanied by decreases in phosphatidylinositol and increases in phosphatidic acid. Glucose and other insulin secretagogues elicited similar changes in amylase release and pancreatic phospholipids; epinephrine blocked these effects of glucose, presumably via inhibition of glucose-induced insulin secretion. Effects of insulin and glucose on phospholipids and amylase release were dependent on Ca2+ in the incubation medium. These findings suggest that, in the pancreas, insulin enhances Ca2+-dependent phosphatidylinositol breakdown, which in turn influences amylase secretion. The effects of insulin on phospholipids may also explain certain other actions of insulin.

Amylases↗
PubMed1981

Effect dietary corn starch intake on pancreatic amylase and intestinal maltase and pH in cattle.

The pH optimum of pancreatic alpha-amylase from grain-fed steers was determined to be 6.9, while that of intestinal maltase was established at 5.8. Both assays were found to be linear up to 1 hr of incubation. The V max of pancreatic amylase was determined to be pancreatic amylase was determined to be 1.15 mg of maltose monohydrate produced/hr. Activities of pancreatic and intestinal maltase were not reduced (P greater than .05) during the interval from sample collection from the animal until analysis 4 hr later when tissues were kept on ice. Twenty-four yearling Holstein steers fed either alfalfa hay at a maintenance level of metabolizable energy (ME) intake or corn at one, two or three times the maintenance ME intake level were slaughtered after being fed 106 days. The pancreas was removed alone with sections of the intestine. Specific activity of pancreatic amylase for steers fed the high level of corn was 129% of that for steers fed the alfalfa diet (P greater than .05). Intestinal maltase activity was highest in the jejunum and decreased toward the ileum. Increasing dietary starch intake resulted in no response (P greater than .05) in maltase activity at 10, 30, 50, 70, or 90% of the small intestine length. The effect of dietary starch level on dieesta pH was dependent on sampling location within the small intestine. There were no dietary effects (P greater than .05) on digesta pH for the first 10% segment of intestine distal to the pylorus. However, in all subsequent sections, digesta pH was higher steers fed the alfalfa diet than for those fed the two higher levels of grain. A calculation for estimating th amount of pancreatic amylase needed to hydrolyze starch presented to small intestine is discussed.

Amylases↗
PubMed1996

Immunohistochemical and quantitative changes in salivary EGF, amylase and haptocorrin following radiotherapy for oral cancer.

Epidermal growth factor (EGF), amylase and haptocorrin are molecules produced in the salivary glands. The aim of the present study was to determine immunohistochemical and quantitative alterations in EGF as compared with haptocorrin and amylase following radiotherapy for oral cancer. Changes in the salivary secretion of EGF are of interest because of the importance of EGF in mucosal regeneration. Immunohistochemical studies on normal tissue from parotid and submandibular glands have demonstrated EGF in the serous acini with a tendency to single cell expression in the parotid gland. Amylase has been found in the serous acini of both the submandibular and parotid glands. Haptocorrin was localized in the duct system of both glands. In the submandibular glands with radiotherapy induced sialoadenitis only very few acini with weak or no staining for EGF and amylase were demonstrated, while no changes were observed in the staining for haptocorrin. Analysis on stimulated whole saliva samples collected from 20 healthy individuals and from 20 patients prior to, and 1, 2 and 3 weeks following radiotherapy showed significant reduction in salivary contents of EGF and amylase after treatment as expressed per g protein (p < 0.0002). The salivary content of haptocorrin increased significantly after treatment (p < 0.002). These alterations may be explained by the different cellular sites of the molecules studied, the serous acini being more sensitive to ionising radiation than the duct system. The concentration of EGF in saliva before treatment was significantly higher in patients than in the control group (p < 0.02), which may indicate that the tumors induce increased secretion of salivary EGF, or alternatively that the oral tumors contribute with EGF to the saliva. In conclusion we have demonstrated a reduction in the mitogenic peptide EGF both immunohistochemically and quantitatively following irradiation for oral cancer, results which may contribute to the understanding of the clinical signs of mucositis.

Aged↗
PubMed1985

Visual tests for urinary amylase investigated in the routine laboratory.

Ninety-seven fresh urine specimens were tested in the routine laboratory with the Rapignost Amylase test strip, and the results were compared to those obtained using Phadebas Amylase test tablets to investigate the transferability of the results obtained by the Rapignost method to those of the Phadebas method under routine conditions. The fraction of conflicting negative results of Phadebas-positive specimens was 9% and the corresponding fraction of conflicting positive results was 13%. An attempt to improve the transferability by changing the comparison scale slightly did not succeed. However, a visual binary test based on 180 s incubation at 37 degrees C of 400 microliters urine in a suspension of a Phadebas Amylase test tablet seemed more suitable in selection of specimens with Phadebas amylase activity less than 2000 U/l (upper limit of the reference interval). These specimens amounted to approximately 75% of all amylase specimens in our laboratory.

Amylases↗
PubMed1995

alpha-Amylase and isoamylase levels in renal transplant recipients compared to uremic patients.

Hyperamylasemia is a common finding in chronic renal failure (CRF) patients. The present study was designed to evaluate the frequency, the type, and the hyperamylasemia levels in renal transplant recipients (RTR) compared to patients with renal failure with or without replacement of renal function. One hundred and forty-one subjects [42 with varying degree of renal insufficiency (group A), 74 on hemodialysis (group B), and 25 RTR (group C)] and 47 normal individuals were studied. Total serum alpha-amylase (Ta) as well as pancreatic (Pa) and salivary (Sa) types of serum isoamylases were elevated in all groups when compared to the levels found in normal subjects. A remarkable proportion of patients belonging to groups A and B had Ta as well as Pa levels over three times the upper normal limits. On the contrary, no RTR had such increased levels of both Ta and isoamylases. A statistically significant correlation was found between Ta, Pa, and Sa and serum creatinine in RTR. However, no statistically significant correlation was found between urine amylases and serum creatinine or between urine and serum levels in all amylases in this group. In conclusion, serum amylase levels are increased in RTR. However, no subject in this group had amylase and isoamylase values more than three times the upper normal limits, which was a common finding in the other groups of patients.

Analysis of Variance↗