Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “AMYLASE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources
PubMed1990

Alpha-amylase gene transcription in tissues of normal dog.

We studied the distribution of alpha-amylase mRNA in normal dog tissues by northern blotting (NB) and reverse transcription-polymerase chain reaction (RT-PCR) with human pancreatic (AMY2) and salivary (AMY1) alpha-amylase cDNA-specific primers. Analysis of poly(A+) RNA from various normal tissues by NB indicated the presence of detectable levels of alpha-amylase mRNA transcripts only in pancreas. Dot-blot analysis of DNA amplified with primers common to both (human) isoamylase mRNAs showed presence of alpha-amylase gene transcripts not only in pancreas but also in liver, small intestine, large intestine and fallopian tube. Traces of amylase gene transcripts were also observed in ovary, uterus and lung. Interestingly, amylase transcripts were not detectable in the parotid gland by NB or RT-PCR. We have also localized alpha-amylase mRNA transcripts to dog pancreas by in situ transcription and in situ hybridization. Our results suggest that there is high degree of homology between the alpha-amylase mRNA sequences in dog and human at least in the exon 3-4 regions of the human gene.

Animals↗
PubMed1995

Skin-prick tests for hypersensitivity to alpha-amylase preparations.

Twenty-five asthmatic subjects with suspected alpha-amylase hypersensitivity were studied by skin-prick tests, a capture ELISA, immunoblotting and bronchial provocation tests. At the same time, different amylases were analysed by SDS-PAGE and immunoblotting using a polyclonal rabbit antiserum. Eight patients showed a positive bronchial response to amylase. Seven of them had positive skin-prick tests, with this method being the most sensitive approach for diagnosis. However, in four cases, skin tests were also positive although the patients had a negative provocation test, thus demonstrating that skin tests are not specific. ELISA and blotting showed similar results in terms of sensitivity and specificity. The enzymes used by the workers included several antigens besides alpha-amylase. The rabbit antiserum to alpha-amylase detected a protein in a wheat flour extract. In one case, the IgE antibodies were specific only for a contaminant of lower molecular weight than amylase. These facts suggest that proteins from the culture medium could be responsible for some cases of amylase hypersensitivity, making the diagnosis difficult. The presence of amylase in another enzymatic extract, a protease produced by Aspergillus oryzae, was proved by means of skin tests and immunoblotting, thus demonstrating the allergenic properties of this enzymatic preparation.

Asthma↗
PubMed1990

Crystallization and preliminary crystallographic study of bacterial alpha-amylases.

Crystallization of bacterial alpha-amylases has been achieved by the hanging-drop vapor diffusion method. The crystals of Bacillus licheniformis and B. licheniformis 584 amylases are isomorphous to each other. The crystals of B. licheniformis amylase belong to the tetragonal system, space group P4(2)2(1)2 with cell dimensions of a = 119.3 and c = 85.4 A. The asymmetric unit contains one molecule of amylase, with a volume per molecular mass, Vm, of 2.75 A3/Da. The crystals of B. licheniformis and B. licheniformis 584 amylases diffract beyond 2.5 A resolution and are suitable for X-ray diffraction analysis. The crystals of B. amyloliquefaciens amylase are orthorhombic, and have space group C222(1), with cell dimensions of a = 154, b = 298, and c = 90 A. The asymmetric unit contains three to five molecules. In the crystallization of B. licheniformis and B. licheniformis 584 amylases, the addition of EDTA was indispensable to obtain large single crystals, while it had an adverse effect on the crystallization of B. amyloliquefaciens amylase, producing a large amount of small crystals.

Bacillus↗
PubMed1991

Cyclic AMP antagonist Rp-cAMPS inhibits amylase exocytosis from saponin-permeabilized parotid acini.

Rp-cAMPS, the Rp-diastereomer of adenosine 3',5'-phosphorothioate, is often referred to as a cAMP antagonist, since it binds to the regulatory subunit of cAMP-dependent protein kinase without dissociation of free catalytic subunits. To evaluate the role of cAMP-dependent protein kinase in amylase exocytosis, we examined the effect of Rp-cAMPS on amylase release from rat parotid acini. Rp-cAMPS did not stimulate amylase release from saponin-permeabilized parotid acini, whereas its Sp-isomer strongly evoked amylase release. Rp-cAMPS dose-dependently inhibited amylase release stimulated by Sp-cAMPS. In the presence of Rp-cAMPS, the dose-response curve of Sp-cAMPS was shifted to the right. The inhibitory effect of Rp-cAMPS on isoproterenol-induced amylase release was not detected in intact acini, but was clearly observed in the permeabilized ones. Rp-cAMPS markedly inhibited protein phosphorylation evoked by Sp-cAMPS, indicating that Rp-cAMPS prevents the dissociation of cAMP-dependent protein kinase. These results, taken together with synergistic increase in amylase release by the combination of site-selective cAMP analogues [T. Takuma (1990) J. Biochem. 108, 99-102], suggest that cAMP-dependent protein kinase is involved in the exocytosis of amylase from parotid acini.

Amylases↗
PubMed1994

PCR cloning and sequencing of the beta-amylase cDNA from barley.

Polymerase chain reaction (PCR) amplification of mRNA from developing barley (cultivar Haruna two-rows) endosperm was used to clone and sequence full-length cDNA encoding beta-amylase. The beta-amylase cDNA was 1,775 bp in length. The beta-amylase was deduced to be composed of 535 amino acid residues and its molecular weight was calculated to be 59,610. Kreis et al. reported that the beta-amylase cDNA from barley (cultivar Hiproly) was 1,754 bp in length and coded for a polypeptide of 535 amino acids [Eur. J. Biochem. (1987) 169, 517-525]. A comparison of the beta-amylase sequences from Haruna two-rows and Hiproly barleys revealed nine differences in the nucleotide sequence which resulted in three changes in the amino acid residues and 21 additional nucleotides at its 3'-end in the cultivar Haruna two-rows. The three changes were as follows: Ala-233, Ser-347, Met-527 (Haruna two-rows) and Val-233, Met-347, Ile-527 (Hiproly). Lundgard and Svensson pointed out that 23 amino acid residues of the peptide fragment derived from the COOH-terminal region of barley (cultivar Gula) beta-amylase were in agreement with the deduced amino acid sequence reported by Kreis et al., with the exception of a single position (Met-527 compared to Ile) [Carlsberg Res. Commun. (1986) 51, 487-491]. Our findings described above showed Met-527 is reasonable. In the cases of beta-amylases from soybean and sweet potato, the positions that corresponded to those at 233 and 347 in the amino acid sequence of beta-amylase from barley were Ala and Ser, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed2005

Involvement of alpha-amylase I-1 in starch degradation in rice chloroplasts.

To determine the role of alpha-amylase isoform I-1 in the degradation of starch in rice leaf chloroplasts, we generated a series of transgenic rice plants with suppressed expression or overexpression of alpha-amylase I-1. In the lines with suppressed expression of alpha-amylase I-1 at both the mRNA and protein levels, seed germination and seedling growth were markedly delayed in comparison with those in the wild-type plants. However, the growth retardation was overcome by supplementation of sugars. Interestingly, a significant increase of starch accumulation in the young leaf tissues was observed under a sugar-supplemented condition. In contrast, the starch content of leaves was reduced in the plants overexpressing alpha-amylase I-1. In immunocytochemical analysis with specific anti-alpha-amylase I-1 antiserum, immuno-gold particles deposited in the chloroplasts and extracellular space in young leaf cells. We further examined the expression and targeting of alpha-amylase I-1 fused with the green fluorescent protein in re-differentiated green cells, and showed that the fluorescence of the expressed fusion protein co-localized with the chlorophyll autofluorescence in the transgenic cells. In addition, mature protein species of alpha-amylase I-1 bearing an oligosaccharide side chain were detected in the isolated chloroplasts. Based on these results, we concluded that alpha-amylase I-1 targets the chloroplasts through the endoplasmic reticulum-Golgi system and plays a significant role in the starch degradation in rice leaves.

Chloroplasts↗
PubMed2000

Analysis of structural and physico-chemical parameters involved in the specificity of binding between alpha-amylases and their inhibitors.

Enzyme-inhibitor specificity was studied for alpha-amylases and their inhibitors. We purified and cloned the cDNAs of two different alpha-amylase inhibitors from the common bean (Phaseolus vulgaris) and have recently cloned the cDNA of an alpha-amylase of the Mexican bean weevil (Zabrotes subfasciatus), which is inhibited by alpha-amylase inhibitor 2 but not by alpha-amylase inhibitor 1. The crystal structure of AI-1 complexed with pancreatic porcine alpha-amylase allowed us to model the structure of AI-2. The structure of Zabrotes subfasciatus alpha-amylase was modeled based on the crystal structure of Tenebrio molitor alpha-amylase. Pairwise AI-1 and AI-2 with PPA and ZSA complexes were modeled. For these complexes we first identified the interface forming residues. In addition, we identified the hydrogen bonds, ionic interactions and loss of hydrophobic surface area resulting from complex formation. The parameters we studied provide insight into the general scheme of binding, but fall short of explaining the specificity of the inhibition. We also introduce three new tools-software packages STING, HORNET and STINGPaint-which efficiently determine the interface forming residues and the ionic interaction data, the hydrogen bond net as well as aid in interpretation of multiple sequence alignment, respectively.

Amino Acid Sequence↗
PubMed2003

Alpha-amylase supplementation of broiler diets based on corn.

A 42-d trial was conducted to study the influence of exogenous alpha-amylase on digestive and performance traits in broilers fed a corn-soybean meal diet. There were two treatments (control and alpha-amylase supplemented diet) and six replicates (14 Cobb male chicks caged together) per treatment. At 7 d of age, alpha-amylase supplementation improved daily gain by 9.4% (P < or = 0.05) and feed conversion by 4.2% (P < or = 0.01). At the end of the trial, birds fed the alpha-amylase-supplemented diet ate more and grew faster (P < or = 0.05) and hadbetter feed conversion (P < or = 0.10) than broilers fed the control diet. Also, alpha-amylase supplementation improved apparent fecal digestibility of organic matter and starch (P < or = 0.01) and AMEn of the diet (P < or = 0.001). However, no effects were detected for CP or fat digestibility. Nutrient digestibility and AMEn of the diet increased with age (P < or = 0.001); however, no interactions of alpha-amylase x age were observed for any trait. Coefficients of apparent ileal and fecal digestibility of starch at 28 d of age were similar, which indicated that most of the undigested starch was not fermented in the hindgut of the chick. alpha-Amylase supplementation reduced relative pancreas weight (P < or = 0.001) but did not affect the weight of the remaining organs. Age consistently reduced intestinal viscosity and relative weights of all the organs (P < or = 0.001). The data indicated that alpha-amylase supplementation of a corn-soybean meal diet improved digestibility of nutrients and performance of broilers.

Aging↗
PubMed1975

Inhibition of serum and urine amylase activity in pancreatitis with hyperlipemia.

In 6 of 7 patients with acute pancreatitis and hyperlipemia, inhibition of serum amylase activity was detected by dilution of the serum before assaying for amylase and by correcting for tthe dilution factor. In 4 patients the inhibition phenomenon disappeared within the first few days of hospitalization as the elevated serum triglycerides fell. However, in 2 others there was no relation between triglyceride level and amylase inhibition. Removal of the excess serum lipids by ultracentrifugation did not eliminate the inhibition of amylase activity. Inhibition of amylase activity also occurred in the urine of these patients. No amylase inhibition was demonstrable in lipemic serum from patients without pancreatitis or in pancreatitis serum to which excess lipids were added. The data suggest the presence of a circulating inhibitor of amylase, distinct from the elevated serum lipids, in the serum and urine of patients with acute pancreatitis associated with hyperlipemia. The diagnosis of acute pancreatitis in the patient with abdominal pain and lactescent serum can be facilitated by correcting the serum amylase activity by dilution.

Acute Disease↗
PubMed1997

Serum amylase level on admission in the diagnosis of blunt injury to the pancreas: its significance and limitations.

OBJECTIVE: The objective of this study was to elucidate the significance and limitations of serum amylase levels in the diagnosis of blunt injury to the pancreas. SUMMARY BACKGROUND DATA: Several recently published reports of analyses of patients with blunt abdominal trauma have indicated that determination of the serum amylase level on admission seemed to be of little value in the diagnosis of acute injury to the pancreas. Few previous reports have described clearly the significance and the limitations of the serum amylase level in diagnosing injury to the pancreas. METHODS: Retrospective analysis of 73 patients with blunt injury to the pancreas during 16-year period from February 1980 to January 1996 was performed. The factors analyzed in the current study included age, gender, time elapsed from injury to admission, hypotension on admission, type of injury to the pancreas, intra-abdominal- and intracranial-associated injuries, and death. RESULTS: The serum amylase level was found to be abnormal in all patients admitted more than 3 hours after trauma. Various comparisons between patients with elevated (n = 61, 83.6%) and nonelevated (n = 12, 16.4%) serum amylase levels showed the statistical significance solely of the time elapsed from injury to admission (7 +/- 1.5 hours vs. 1.3 +/- 0.2 hour, p < 0.001). The major factor that influences the serum amylase level on admission appeared to be the time elapsed from injury to admission. Determination of the serum amylase level is not diagnostic within 3 hours or fewer after trauma, irrespective of the type of injury. CONCLUSIONS: To avoid failure in the detection of pancreatic injury, the authors advocate determination of serum amylase levels more than 3 hours after trauma.

Abdominal Injuries↗
PubMed1988

Galanin inhibits amylase secretion from isolated rat pancreatic acini.

The neuropeptide galanin is present in intrapancreatic nerve fibers and is known to affect the secretion of the islet hormones. Its most potent effect is thereby the inhibition of insulin secretion. In the present study, we investigated whether galanin influences amylase secretion from isolated rat pancreatic acini. Acini were isolated by the collagenase digestion technique and incubated for 45 min in a Krebs-Henseleit medium with or without addition of the cholinergic agonist carbachol or the C-terminal octapeptide of cholecystokinin (CCK-8) in the presence or absence of galanin. Carbachol, at its optimal concentration (10(-5) M), stimulated amylase secretion to 11.8 +/- 0.5% of total amylase content compared to 4.3 +/- 0.3% in controls (p less than 0.001). Galanin, (10(-8)-10(-9) M), reduced the carbachol-induced amylase secretion to 10.4 +/- 0.3% (p less than 0.01). Galanin at concentration levels below 10(-10) M had no significant effect. At 10(-8) M, CCK-8 stimulated amylase secretion to 9.7 +/- 0.6% compared with 5.2 +/- 0.3% in controls (p less than 0.01). Galanin (10(-7) M) reduced this stimulation to 8.0 +/- 0.4% (p less than 0.05). Galanin did not affect basal amylase secretion. It is concluded that the intrapancreatic neuropeptide galanin weakly inhibits carbachol- and CCK-8-induced amylase secretion from isolated rat pancreatic acini. Thus, galanin has the capability to directly affect not only endocrine but also exocrine pancreatic secretion although its effect of inhibiting amylase secretion seems weak.

Amylases↗
PubMed1997

Endogenous arachidonic acid release and pancreatic amylase secretion.

Recent studies have suggested the involvement of phospholipase A2 (PLA2) in pancreatic amylase secretion. The present study was designed to investigate the secretory role of arachidonic acid (AA) in carbachol (Cch)-stimulated rat pancreatic acini and its origin. From enzymatic assays, PLA2 and diacylglycerol (DAG) lipase were activated by Cch and respectively inhibited by the PLA2 inhibitors, mepacrine and aristolochic acid, and by the DAG lipase inhibitor, RHC 80267. Melittin-activated PLA2 activity was also inhibited by the PLA2 inhibitors. Cch-stimulated endogenous AA release from pancreatic acini was partially inhibited by 150 microM RHC 80267 and by 150 microM mepacrine or 200 microM aristolochic acid and totally inhibited by a combination of the two enzyme inhibitors. Exogenous AA caused amylase release in a concentration-dependent manner. Eicosatetraynoic acid (a cyclooxygenase and lipoxygenase inhibitor), significantly increased basal and Cch-induced AA release and amylase secretion. RHC 80267 and the PLA2 inhibitors separately and partially suppressed Cch-stimulated amylase secretion, with an additive effect observed when the DAG lipase and the PLA2 inhibitors were combined. A combination of RHC 80267, mepacrine, or aristolochic acid and the phospholipase C (PLC) inhibitor U73122 completely inhibited Cch-stimulated amylase secretion. Finally, the PLA2 activator melittin-stimulated amylase secretion was blocked by the two PLA2 inhibitors. We conclude that exogenous and endogenous AA can induce amylase secretion. Therefore, AA released from either PLC-DAG lipase or PLA2 pathways can be considered an additional and important intracellular mediator of amylase secretion.

Amylases↗
PubMed1998

A comparison of lipase and amylase in the diagnosis of acute pancreatitis in patients with abdominal pain.

The clinical value of amylase and lipase measurement for the diagnosis of acute pancreatitis was evaluated in 253 patients presenting with acute abdominal pain. Acute pancreatitis was detected in 32 patients by computed tomography or ultrasound. In the serum samples collected on days 0-1 after the onset of symptoms, lipase was elevated in 100% and amylase in 95%. A 95% sensitivity/specificity was reached at a lipase cutoff near twofold above normal. The receiver-operating characteristics (ROC) showed similar curves for both enzymes, lipase being slightly superior to amylase. The ROC curves from days 2-3 demonstrated a much lower sensitivity/specificity of both enzymes. Lipase, however, was notably superior to amylase: at a sensitivity of 85% the specificity of lipase (amylase) was 82% (68%). In samples from days 4-5 the accuracy of the enzyme assays was even worse; at a sensitivity of 60% the specificity did not increase above 70%. The diagnostic value of simultaneous measurement of amylase and lipase was tested at different cutoffs in two groups: the OR group, in which one of the two parameters had to be elevated, and the AND group, in which both parameters had to be above normal. Combination of both parameters mainly improved the specificity of the assay (from 91 to 98% on days 2-3 and from 93 to 97% on day 4-5) but only when, in the OR group, twofold elevated amylase was combined with lipase. We conclude that the simultaneous determination of serum lipase and amylase marginally improved the diagnosis of acute pancreatitis in patients with acute abdominal pain, however, the sensitivity of the assay with samples collected 4-5 days after onset of the disease remained low.

Abdominal Pain↗
PubMed2002

Dibutyltin dichloride modifies amylase release from isolated rat pancreatic acini.

INTRODUCTION: Dibutyltin dichloride (DBTC) is widely used as a stabilizer for polyvinylchloride plastics and is of particular toxicologic interest. AIM: To examine the effects of DBTC on pancreatic exocrine function in isolated rat pancreatic acini. METHODOLOGY: Isolated rat pancreatic acini were incubated with various secretagogues in the presence or absence of DBTC. We investigated the effects of DBTC on amylase release, receptor binding, and protein kinase C (PKC) enzyme activity. RESULTS: DBTC reduced cholecystokinin octapeptide (CCK-8)-stimulated and carbamylcholine-stimulated amylase release and the binding of [(125)I]CCK-8 to isolated rat pancreatic acini. Conversely, DBTC potentiated secretin-stimulated amylase release, although it slightly inhibited [(125)I]secretin binding to its receptors. In addition, DBTC potentiated amylase release stimulated by vasoactive intestinal peptide, 8-bromoadenosine 3', 5'-monophosphate (8Br-cAMP) or calcium ionophore A23187, whereas it had no influence on amylase release stimulated by 12-O-tetradecanoylphorbol 13-acetate. The protein kinase C (PKC) inhibitor calphostin C abolished the DBTC-induced potentiation of amylase release stimulated by 8Br-cAMP or A23187. Moreover, DBTC caused a significant translocation of PKC enzyme activity from cytosol to membrane fraction. CONCLUSIONS: These results indicate that DBTC reduces CCK-8- and carbamylcholine-stimulated amylase release by inhibiting their receptor bindings to pancreatic acini, whereas it potentiates cAMP-mediated amylase release by activating PKC in isolated rat pancreatic acini.

Amylases↗
PubMed1992

Structure of yeast pGKL 128-kDa killer-toxin secretion signal sequence. Processing of the 128-kDa killer-toxin-secretion-signal-alpha-amylase fusion protein.

The linear double-stranded DNA plasmid pGKL1 in yeast encodes a killer toxin consisting of 97-kDa, 31-kDa and 28-kDa subunits. A 128-kDa protein precursor of the 97-kDa and 31-kDa subunits, was first synthesized with a 29-amino-acid extension at its NH2-terminus as a secretion signal sequence. In the present study, the property of this signal sequence was studied by the analysis of a fusion protein with mouse alpha-amylase. Using the secretion signal sequence of the killer protein, the mouse alpha-amylase was successfully secreted into the culture medium. An intracellular precursor form of alpha-amylase was identified and purified. Analysis of the NH2-terminal sequence of this precursor molecule indicated that it corresponded to the secretory intermediate (pro form) of alpha-amylase with the removal of the hydrophobic segment (Met1-Gly16) of the secretion signal. Both the secretion of alpha-amylase into the culture medium and the detection of the pro-alpha-amylase species in the cells were prohibited by a sec 11 mutation, or by the conversion of Gly to Val at the 16th position of the secretion signal. These results strongly suggest that the cleavage occurs between Gly16 and Leu17 by a signal peptidase, and that this cleavage is required for the secretion of alpha-amylase into the medium. Based on the data from the NH2-terminal amino acid sequences of secreted alpha-amylases, we conclude that the 29-amino-acid secretion signal present in the 128-kDa killer toxin precursor protein is a prepro structure.

Amino Acid Sequence↗
PubMed1993

Expression and mutation of soybean beta-amylase in Escherichia coli.

The cDNA clones corresponding to soybean beta-amylase mRNA were isolated and sequenced. The cDNA contained an open-reading frame composed of 496 amino acids. The comparison of the amino acid sequence deduced from the cDNA with the N-terminal peptide sequence from mature enzyme proved that beta-amylase had no leader sequence. Employing the cDNA, the beta-amylase was directly synthesized in Escherichia coli by the expression vector pKK233-2 controlled by the tac promoter. The enzyme activity detected in E. coli lysate drastically increased with a lower cultivation temperature, and the total activity and specific activity of the enzyme in E. coli lysate cultured at 13 degrees C was 130-fold and 280-fold, respectively, the value at 37 degrees C. The enzyme produced in E. coli was purified by the affinity column chromatography of cyclomaltohexaose-immobilized Sepharose 6B. Employing the established expression and purification system of the enzyme, the functional ionizable groups in the active site were searched. His93, involving an imidazole, and Asp348, involving a carboxylate, in the highly conserved regions within the beta-amylases were replaced by Arg (H93R) and Ash (D348N) by site-directed mutagenesis, respectively. All beta-amylases, including the non-mutant and mutant beta-amylases, produced in E. coli exhibited lower Vmax values than that of beta-amylase isolated conventionally from soybean seeds. Especially the Vmax value of [H93R]beta-amylase was reduced drastically compared to that of the non-mutant; however, none of them lost their enzyme activities completely. Therefore, neither His93 nor Asp348 may participate in the catalytic reaction directly.

Amino Acid Sequence↗
PubMed1994

Comparison of amylase-binding proteins in oral streptococci.

Certain species of oral streptococci bind salivary amylase to their cell surface. The patterns of amylase-binding proteins produced by a range of streptococci have been compared by ligand blotting and several characteristics of the binding proteins investigated. Streptococcus gordonii was the most homogeneous species and almost all strains produced proteins migrating with molecular mass 82 kDa and 20 kDa. Other species were more heterogeneous, releasing proteins that resolved at 87 or 82 kDa and/or between 20 and 36 kDa. Binding of amylase to the 82/87-kDa proteins on ligand blots was prevented by amylase inhibitors, amylase substrates and periodate treatment but these had limited or no effect on amylase binding to 20-36 kDa proteins. Also, the 20 kDa protein of S. gordonii Challis was released into culture medium before the 82-kDa protein. These data suggest that there is significant variation in amylase-binding proteins among streptococci and that the high and low molecular mass proteins differ in the way they interact with salivary amylase.

Amylases↗
PubMed1978

Relation of amylase to starch and Lycasin metabolism in human dental plaque in vitro.

Acid production activity (APA) in plaque suspensions from glucose, boiled soluble starch and hydrogenated starch hydrolysate (Lycasin) was studied in 11 subjects. Amylase (alpha-1,4-glucan 4-glucanohydrolase, EC 3.2.1.1) activity was measured in plaque and whole saliva samples from the same persons. Lycasin was found to be hydrolyzed by salivary amylase under the formation of di- and oligosaccharides, however, with a lower rate than starch. A high correlation was found between APA from glucose and from soluble starch and between APA from soluble starch and plaque amylase activity. No correlation was found between amylase activity in saliva and APA from soluble starch or between amylase activity in saliva or plaque and APA from Lycasin. APA from Lycasin was about 62% and from soluble starch about 76% of the APA from glucose. 0-25% of the total number of cultivable microorganisms from the plaque produced extracellular starch-degrading enzymes. No correlation was found between number of starch-degrading microorganisms and APA from soluble starch or between these numbers and the plaque amylase activity. By electrophoreses only amylase fractions of human origin were found in whole saliva, plaque supernatants and plaque suspensions, indicating that the microbial amylase activity in the plaque is low compared with that of salivary origin.

Acids↗