BACKGROUND The possible existence of an acini–islet–acinar(AIA)reflex,involving mutual amylase and insulin interactions,was investigated in the current acute experiment on pigs.AIM To confirm the existence of an AIA...BACKGROUND The possible existence of an acini–islet–acinar(AIA)reflex,involving mutual amylase and insulin interactions,was investigated in the current acute experiment on pigs.AIM To confirm the existence of an AIA reflex and justify the placement of the exocrine and endocrine pancreatic components within the same organ.METHODS The study was performed on six pigs under general anesthesia.An intravenous glucose tolerance test was performed,with a bolus infusion of 50%glucose to the jugular vein,while amylase(5000 U/kg)or vehicle intrapancreatic infusions were administered via the pancreaticoduodenalis cranialis artery during 30 min with a 1 mL/min flow rate.RESULTS The amylase infusion to pancreatic arterial circulation inhibited and delayed the insulin release peak which is usually associated with the highest value of blood glucose and is typically observed at 15 min after glucose infusion,for>1 h.The intrapancreatic infusion of the vehicle(saline)did not have any effect on the time frame of insulin release.Infusion of 1%bovine serum albumin changed the insulin release curve dramatically and prolonged the high range of insulin secretion,far beyond the glucose peak.CONCLUSION Intrapancreatic arterial infusion of amylase interrupted the integrated glucose–insulin interactions.This confirms an AIA reflex and justifies placement of the exocrine and endocrine pancreatic components within the same organ.展开更多
目的:分析血清淀粉酶(Amylase,AMY)、同型半胱氨酸(Homocysteine,Hcy)、D-二聚体(D-dimer,D-D)水平及联合检测对急性胰腺炎(Acutepancreatitis,AP)患者预后的预测价值。方法:选取2020年5月-2023年6月期间本院收治的AP患者为研究对象。...目的:分析血清淀粉酶(Amylase,AMY)、同型半胱氨酸(Homocysteine,Hcy)、D-二聚体(D-dimer,D-D)水平及联合检测对急性胰腺炎(Acutepancreatitis,AP)患者预后的预测价值。方法:选取2020年5月-2023年6月期间本院收治的AP患者为研究对象。根据患者治疗后的预后情况,将患者分为预后良好组(43例)及预后不良组(19例)。收集并对比两组的一般资料及血清AMY、Hcy、D-D水平。logistic回归模型分析影响AP患者预后的影响因素。分析血清各指标水平联合检测对AP预后的预测效能。结果:预后不良组入院时急性生理功能和慢性健康状况评分系统Ⅱ(Acute physiological function and Chronic health status score SystemⅡscore,APACHEⅡ)评分及血清Hcy、AMY、D-D水平均显著高于预后良好组(P<0.05)。Logistic回归分析显示,入院时血清Hcy、AMY、D-D及APACHEⅡ评分均为患者发生预后不良的危险因素(P<0.05)。入院时AMY、Hcy、D-D水平联合预测患者发生预后不良的曲线下面积(AUC)为0.879。结论:血清AMY、Hcy、D-D水平与AP患者预后密切相关,三者联合检测在患者预后评估中具有重要价值。展开更多
[ Objective] The study was to understand the changes of amylase(AMY) and superoxide dismutase(SOD) isozymes during the ger- mination process of Emmenopterys henryi Oliv seeds. [ Metbod] By employing polyacrylamide...[ Objective] The study was to understand the changes of amylase(AMY) and superoxide dismutase(SOD) isozymes during the ger- mination process of Emmenopterys henryi Oliv seeds. [ Metbod] By employing polyacrylamide gel electrophoresis method, the expressions of AMY and SOD isozymes during seed germination process were analyzed. ~ Result] The main AMY bands remained strong during the whole peri- od and a new band A2 appeared in the middle and late period of seed germination. Some new SOD bands occurred at the early stage, then be- came weak or disappeared in the middle period, and band S6 became intense in the late peried. [ Conclusion.] The expression of AMY and SOD isozyme gene has temporal difference during germination of E. henryi Oliv seeds.展开更多
[Objective] The aims were to investigate the screening and identification of amylase-producing marine bacteria from Arctic sea and the optimization of the amylase producing conditions. [Method] A high-yield strain for...[Objective] The aims were to investigate the screening and identification of amylase-producing marine bacteria from Arctic sea and the optimization of the amylase producing conditions. [Method] A high-yield strain for producing amylase named ArcB84A was isolated from a total of 156 marine bacteria of Arctic sea. Then,the morphological identification of the strain,molecular identification of 16S rRNA and optimization of fermentation conditions were conducted. [Result] ArcB84A strain was a member of Pseudoalteromonas genus. The optimum conditions for enzyme production of B84A strain included that,the initial pH value of the medium was 7.0-8.0,and the best carbon and nitrogen sources respectively were 5‰ glucose and peptone. Surfactants including TritonX-100,Tween20 and Tween80 could increase amylase activity of the strain,in which,the effect of 10‰ Tween80 was the most obvious.展开更多
Starch degradation in cells is closely associated with cereal seed germination, photosynthesis in leaves, carbohydrate storage in tuberous roots, and fleshy fruit development. α_Amylase is considered as one of the ke...Starch degradation in cells is closely associated with cereal seed germination, photosynthesis in leaves, carbohydrate storage in tuberous roots, and fleshy fruit development. α_Amylase is considered as one of the key enzymes catalyzing starch breakdown, but up to date its role in starch breakdown in living cells remains unclear because the enzyme was often shown extrachloroplastic in living cells. The present experiment showed that α_amylase activity was progressively increasing concomitantly with the decreasing starch concentrations during the development of apple ( Malus domestica Borkh cv. Starkrimson) fruit. The apparent amount of α_amylase assessed by Western blotting also increased during the fruit development, which is consistent with the seasonal changes in the enzyme activity. The enzyme subcellular_localization studies via immunogold electron_ microscopy technique showed that α_amylase visualized by gold particles was predominantly located in plastids, but the gold particles were scarcely found in other subcellular compartments. A high density of the enzyme was observed at the periphery of starch granules during the middle and late developmental stages. These data proved that the enzyme is compartmented in its functional sites in the living cells of the fruit. The predominantly plastid_distributed pattern of α_amylase in cells was shown unchanged throughout the fruit development. The density of gold particles (α_amylase) in plastids was increasing during the fruit development, which is consistent with the results of Western blotting. So it is considered that α_amylase is involved in starch hydrolysis in plastids of the fruit cells.展开更多
Objective] The aim of this study was to investigate the effects of exoge-nous amylases and Ca2+, Mn2+ and K+ on the amylase specific activities and starch degradation of the upper leaves of 'KRK26' planted in Yun...Objective] The aim of this study was to investigate the effects of exoge-nous amylases and Ca2+, Mn2+ and K+ on the amylase specific activities and starch degradation of the upper leaves of 'KRK26' planted in Yunnan Province during flue-curing. [Method] The amylase specific activities and starch degradation of the leaves were determined by using spectrophotometry. [Result] The 8 U/g exogenous α-amy-lase could improve the specific activity of the leaf α-amylase at yel owing and color-fixing stages, but could not at stem-drying stage, and similarly, the 80 U/g exoge-nous β-amylase could improved the specific activity of the leaf β-amylase at the yel owing stage and the early period of color-fixing stage. The leaf starch could be enhanced to degrade by the exogenous α- or β-amylases and the enhancing effect of the former was stronger than that of the later. 1.50 mg/ml Ca2+ improved the specific activity of the leaf (α+β)-amylase mainly due to its enhancing effect on the leaf α-amylase, and increased the starch degradation. 4 mmol/L Mn2+ inhibited the leaf α-amylase from yel owing to the early period of color-fixing and the β- and (α+β)-amylases from the yel owing to the later period of color-fixing, but enhanced the leafα-amylase from the later period of color-fixing to the later period of stem-drying and the β- and (α+β)-amylases at the later period of stem-drying. Meanwhile, Mn2+ ham-pered the starch degradation during yel owing, but promoted it from the early period of color-fixing to stem-drying. 1 mg/ml K+ enhanced the leaf α-, β- and (α+β)-amy-lases during the yel owing stage, but lowered them from the early period of color-fix-ing to the later period of stem-drying, and always inhibited the leaf starch degrada-tion. [Conclusion] The exogenous α-, β- amylases and Ca2+ of suitable concentra-tions could be used to treat the tobacco leaves before flue-curing to improve the leaf starch degradation during the curing.展开更多
A seed is the carrier of life,and research on the heat and mass transfer of a seed has already stridden toward the level of microcosm,such as cell protoplasm,cell organism,and molecular membrane.By means of a transmis...A seed is the carrier of life,and research on the heat and mass transfer of a seed has already stridden toward the level of microcosm,such as cell protoplasm,cell organism,and molecular membrane.By means of a transmission electron microscope,the authors of this paper observed the microstructure of cotyledon tissue slices of the Chinese cabbage seed with a moisture content of 13% (on dry basis) and that with a moisture content of 4.3% (on dry basis) for drying 2 h at 45 ℃.The compared result was that only wrinkles had been discovered on the cell walls of the seed dried for 2 h,without any significant change for other organelles.Study on the enzyme activity shows that after a germination for 48 h,the relative activity of α amylase of the Chinese cabbage seed dried for 2 h at 45 ℃,decreased by 5.8%,whereas that of the seed dried 2 h at a temperature of 67 ℃ decreased by 30.1%.This work shows that the drying factors have greatly influence on the seed microstructure,enzyme activity,which is directly positive to seed viability.Combined with the analysis of the critical safe drying temperature of the vegetable seed,it can be concluded that enzyme activity is also the function of the drying temperature,the moisture content and the drying time.展开更多
[Objective] The aim was to study the effect of mercury stress on seed germination and seedlings growth.[Method]using Zhengzhou 9023 as the experimental material and cultured in water,to study the effect of the germina...[Objective] The aim was to study the effect of mercury stress on seed germination and seedlings growth.[Method]using Zhengzhou 9023 as the experimental material and cultured in water,to study the effect of the germinating rate,seedling height,root length,seedling's fresh weight,the activities of peroxidase(POD)and amylase in leaf,root and germinating embryo at different concentrations of Hg2+(0.025,0.050,0.100,0.200,0.300,0.400,0.500 mmol/L).[Result]Low concentrations of Hg2+(≤ 0.10 mmol/L)have little effect on seed germination,seedling height,root length and fresh weight;high concentrations of Hg2+( 0.10 mmol/L)have significantly inhibited seed germination and seedling growth.Low concentration of Hg2+(≥ 0.025 mmol/L)could increase POD activity and inhibit the amylase activity significantly,and the effects have increased with the increasing of Hg2+ concentrations.[Conclusion]Hg2+ stress could change the activities of POD and amylase in leaf,root and germinating embryo,influence the energy and substrate supply which was required for normal metabolism of lipid oxidation,and inhibit seedling growth ultimately.展开更多
Starch degradation in cells is closely associated with cereal seed germination, photosynthesis in leaves, carbohydrate storage in tuber and tuberous roots, and fleshy fruit development. Based on previously reported ...Starch degradation in cells is closely associated with cereal seed germination, photosynthesis in leaves, carbohydrate storage in tuber and tuberous roots, and fleshy fruit development. Based on previously reported in vitro assays, β amylase is considered as one of the key enzymes catalyzing starch breakdown, but up to date its role in starch breakdown in living cells remains unclear because the enzyme was shown often extrachloroplastic in living cells. Recently we have shown for the first time that β_amylase is predominantly immuno_localized to plastids in living cells of developing apple fruit. But it remains to know whether this model of β_amylase compartmentation is more widespread in plant living cells. The present experiment, conducted in tuberous root of sweet potato ( Ipomea batatas Lam. cv. Xushu 18) and via immunogold electron_microscopy technique, showed that β amylase visualized by gold particles was predominantly localized in plastids especially at periphery of starch granules, but the gold particles were scarcely found in other subcellular compartments, indicating that the enzyme is subcellularly compartmented in the same zone as its starch substrates. The density of gold particles (β amylase) in plastids was increasing during growing season, but the predominantly plastid_distributed pattern of β amylase in cells was shown unchanged throughout the tuberous root development. These data prove that the enzyme is compartmented in its functional sites, and so provide evidence to support the possible widespread biological function of the enzyme in catalyzing starch breakdown in plant living cells or at least in living cells of plant storage organs.展开更多
For the last decade, low serum amylase(hypoamylasemia) has been reported in certain common cardiometabolic conditions such as obesity, diabetes(regardless of type), and metabolic syndrome, all of which appear to have ...For the last decade, low serum amylase(hypoamylasemia) has been reported in certain common cardiometabolic conditions such as obesity, diabetes(regardless of type), and metabolic syndrome, all of which appear to have a common etiology of insufficient insulin action due to insulin resistance and/or diminished insulin secretion. Some clinical studies have shown that salivary amylase may be preferentially decreased in obese individuals, whereas others have revealed that pancreatic amylase may be preferentially decreased in diabetic subjects with insulin dependence. Despite this accumulated evidence, the clinical relevance of serum, salivary, and pancreatic amylase and the underlying mechanisms have not been fully elucidated. In recent years, copy number variations(CNVs) in the salivary amylase gene(AMY1), which range more broadly than the pancreatic amylase gene(AMY2A and AMY2B), have been shown to be well correlated with salivary and serum amylase levels. In addition, low CNV of AMY1, indicating low salivary amylase, was associated with insulin resistance, obesity, low taste perception/satiety, and postprandial hyperglycemia through impaired insulin secretion at early cephalic phase. In most populations, insulin-dependent diabetes is less prevalent(minor contribution) compared with insulin-independent diabetes, and obesity is highly prevalent compared with low body weight. Therefore, obesity as a condition that elicits cardiometabolic diseases relating to insulin resistance(major contribution) may be a common determinant for low serum amylase in a general population. In this review, the novel interpretation of low serum, salivary, and pancreas amylase is discussed in terms of major contributions of obesity, diabetes, and metabolic syndrome.展开更多
The changes in the activity of amylase and amylase-isoenzyme and the degradation of starch and pigment of tobacco leaf during flue-curing were studied by using the electric- heated flue-curing barn designed and made...The changes in the activity of amylase and amylase-isoenzyme and the degradation of starch and pigment of tobacco leaf during flue-curing were studied by using the electric- heated flue-curing barn designed and made by the Henan Agricultural University. The temperature and humidity of the barn were controlled automatically. The results indicated that starch in tobacco leaf decreased rapidly and leveled off after 48 h of curring, in the meantime, the content of soluble sugar increased accordingly and reached a peak at the stage of color-fixing. Both of them had a rapid-changing stage in the first 36 hours of yellowing. The changes of starch and soluble sugar contents had highly significant negative-correlation at 1 % level (rNC89 = -0.8962**, rYY85 = -0.9704**). The activity of amylase increased with the proceeding of curing and reached a peak after 36 hours of curing, then decreased. But the activity of amylase kept at a high level when the humidity of curing-environment was very low, even if the tobacco leaf had been dried. The rapid degradation of starch showed a significantly negative correlation with the increase of activity of amylase at 5 % level (rNC89 = -0.8495*, rYY85 = -0.7839*). The degradation of starch and pigment had the same regulation and had highly significant correlation at 1 % level (rNC89= 0.9649**, rYY85= 0.9428**). There were mainly three amylase-isoenzyme bands -A, B, C respectively, in tobacco leaf during flue curing. They were identified as α-AMY, β-AMY, R-AMY, and the activity of β-AMY was the highest. The changes in amylase activity and contents of starch and pigment were affected by the tobacco leaf moisture and environmental humidity during curing.展开更多
Two rice varieties, Xiushui 110 with high cadmium (Cd) tolerance and Xiushui 11 with low Cd tolerance were used to study the effects of Cd stress on seed germination, seedling growth and amylase activities. The low ca...Two rice varieties, Xiushui 110 with high cadmium (Cd) tolerance and Xiushui 11 with low Cd tolerance were used to study the effects of Cd stress on seed germination, seedling growth and amylase activities. The low cadmium concentration had little effect on seed germination rate. However, cadmium stress could significantly inhibit plumule and radicle growth, especially for radicle growth. Germination index, vigour index, radicle length and amylase activities of Xiushui 11 decreased more significantly with the increasing cadmium level compared with Xiushui 110. The cadmium content in seedlings of Xiushui 11 was higher than that in Xiushui 110 when the cadmium concentration exceeded 5 μmol/L, which caused lower mitotic index in root tips and amylase activities, and more serious cadmium toxicity in Xiushui 11.展开更多
Postprandial hyperglycemia is an early indication of type 2 diabetes and the target of many anti-diabetic and anti-obesity studies.α-Glucosidase and α-amylase are the crucial factors in regulating starch digestion a...Postprandial hyperglycemia is an early indication of type 2 diabetes and the target of many anti-diabetic and anti-obesity studies.α-Glucosidase and α-amylase are the crucial factors in regulating starch digestion and glucose absorption,making them key targets for many studies to treat postprandial hyperglycemia.We studied the inhibitory activities of microalgal fucoxanthin against rat-intestinalα-glucosidase and pancreaticα-amylase along with the antidiabetic eff ect to induce diff erentiation in 3T3-L1 pre-adipocytes using Oil Red-O staining.Fucoxanthin displayed strong hindrance activities towardα-amylase in a concentration-dependent manner,with an IC50 value of 0.68mmol/L,whereas weak inhibitory activity against α-glucosidase,with an IC 50 value of 4.75 mmol/L.Fucoxanthin also considerably elevated glucose oxidase activity in 3T3-L1 cells by 31.3%at 5μmol/L.During adipocyte differentiation,fucoxanthin showed lipid accumulation in 3T3-L1 cells with no cytotoxicity up to 20μmol/L.However,fucoxanthin had no inhibitory activity on glucose-6-phosphate dehydrogenase.These results suggest that fucoxanthin might be useful for the prevention of obesity or diabetes by inhibiting carbohydrate-hydrolyzing enzymes and lipid accumulation and be utilized as an ingredient for a functional food or dietary supplement.展开更多
文摘BACKGROUND The possible existence of an acini–islet–acinar(AIA)reflex,involving mutual amylase and insulin interactions,was investigated in the current acute experiment on pigs.AIM To confirm the existence of an AIA reflex and justify the placement of the exocrine and endocrine pancreatic components within the same organ.METHODS The study was performed on six pigs under general anesthesia.An intravenous glucose tolerance test was performed,with a bolus infusion of 50%glucose to the jugular vein,while amylase(5000 U/kg)or vehicle intrapancreatic infusions were administered via the pancreaticoduodenalis cranialis artery during 30 min with a 1 mL/min flow rate.RESULTS The amylase infusion to pancreatic arterial circulation inhibited and delayed the insulin release peak which is usually associated with the highest value of blood glucose and is typically observed at 15 min after glucose infusion,for>1 h.The intrapancreatic infusion of the vehicle(saline)did not have any effect on the time frame of insulin release.Infusion of 1%bovine serum albumin changed the insulin release curve dramatically and prolonged the high range of insulin secretion,far beyond the glucose peak.CONCLUSION Intrapancreatic arterial infusion of amylase interrupted the integrated glucose–insulin interactions.This confirms an AIA reflex and justifies placement of the exocrine and endocrine pancreatic components within the same organ.
文摘目的:分析血清淀粉酶(Amylase,AMY)、同型半胱氨酸(Homocysteine,Hcy)、D-二聚体(D-dimer,D-D)水平及联合检测对急性胰腺炎(Acutepancreatitis,AP)患者预后的预测价值。方法:选取2020年5月-2023年6月期间本院收治的AP患者为研究对象。根据患者治疗后的预后情况,将患者分为预后良好组(43例)及预后不良组(19例)。收集并对比两组的一般资料及血清AMY、Hcy、D-D水平。logistic回归模型分析影响AP患者预后的影响因素。分析血清各指标水平联合检测对AP预后的预测效能。结果:预后不良组入院时急性生理功能和慢性健康状况评分系统Ⅱ(Acute physiological function and Chronic health status score SystemⅡscore,APACHEⅡ)评分及血清Hcy、AMY、D-D水平均显著高于预后良好组(P<0.05)。Logistic回归分析显示,入院时血清Hcy、AMY、D-D及APACHEⅡ评分均为患者发生预后不良的危险因素(P<0.05)。入院时AMY、Hcy、D-D水平联合预测患者发生预后不良的曲线下面积(AUC)为0.879。结论:血清AMY、Hcy、D-D水平与AP患者预后密切相关,三者联合检测在患者预后评估中具有重要价值。
文摘[ Objective] The study was to understand the changes of amylase(AMY) and superoxide dismutase(SOD) isozymes during the ger- mination process of Emmenopterys henryi Oliv seeds. [ Metbod] By employing polyacrylamide gel electrophoresis method, the expressions of AMY and SOD isozymes during seed germination process were analyzed. ~ Result] The main AMY bands remained strong during the whole peri- od and a new band A2 appeared in the middle and late period of seed germination. Some new SOD bands occurred at the early stage, then be- came weak or disappeared in the middle period, and band S6 became intense in the late peried. [ Conclusion.] The expression of AMY and SOD isozyme gene has temporal difference during germination of E. henryi Oliv seeds.
基金Supported by International S&T Cooperation Program of China (No.2007DFA21300)Open Research Fund Program of the Ningbo Key Laboratory (No.2007A22007)+1 种基金Zhejiang Xinmiao Excellent Talents Program (No.2008R40G2210031)Education of Zhejiang Province Program (No.20060190)~~
文摘[Objective] The aims were to investigate the screening and identification of amylase-producing marine bacteria from Arctic sea and the optimization of the amylase producing conditions. [Method] A high-yield strain for producing amylase named ArcB84A was isolated from a total of 156 marine bacteria of Arctic sea. Then,the morphological identification of the strain,molecular identification of 16S rRNA and optimization of fermentation conditions were conducted. [Result] ArcB84A strain was a member of Pseudoalteromonas genus. The optimum conditions for enzyme production of B84A strain included that,the initial pH value of the medium was 7.0-8.0,and the best carbon and nitrogen sources respectively were 5‰ glucose and peptone. Surfactants including TritonX-100,Tween20 and Tween80 could increase amylase activity of the strain,in which,the effect of 10‰ Tween80 was the most obvious.
文摘Starch degradation in cells is closely associated with cereal seed germination, photosynthesis in leaves, carbohydrate storage in tuberous roots, and fleshy fruit development. α_Amylase is considered as one of the key enzymes catalyzing starch breakdown, but up to date its role in starch breakdown in living cells remains unclear because the enzyme was often shown extrachloroplastic in living cells. The present experiment showed that α_amylase activity was progressively increasing concomitantly with the decreasing starch concentrations during the development of apple ( Malus domestica Borkh cv. Starkrimson) fruit. The apparent amount of α_amylase assessed by Western blotting also increased during the fruit development, which is consistent with the seasonal changes in the enzyme activity. The enzyme subcellular_localization studies via immunogold electron_ microscopy technique showed that α_amylase visualized by gold particles was predominantly located in plastids, but the gold particles were scarcely found in other subcellular compartments. A high density of the enzyme was observed at the periphery of starch granules during the middle and late developmental stages. These data proved that the enzyme is compartmented in its functional sites in the living cells of the fruit. The predominantly plastid_distributed pattern of α_amylase in cells was shown unchanged throughout the fruit development. The density of gold particles (α_amylase) in plastids was increasing during the fruit development, which is consistent with the results of Western blotting. So it is considered that α_amylase is involved in starch hydrolysis in plastids of the fruit cells.
基金Supported by Fund from Yunnan Academy of Tobacco Agricultural Sciences for Comparative Study of the Flue-cured Tobaccos of the New Tobacco-growing Areas in Yunnan Province and Those of Zimbabwe(09YN001)~~
文摘Objective] The aim of this study was to investigate the effects of exoge-nous amylases and Ca2+, Mn2+ and K+ on the amylase specific activities and starch degradation of the upper leaves of 'KRK26' planted in Yunnan Province during flue-curing. [Method] The amylase specific activities and starch degradation of the leaves were determined by using spectrophotometry. [Result] The 8 U/g exogenous α-amy-lase could improve the specific activity of the leaf α-amylase at yel owing and color-fixing stages, but could not at stem-drying stage, and similarly, the 80 U/g exoge-nous β-amylase could improved the specific activity of the leaf β-amylase at the yel owing stage and the early period of color-fixing stage. The leaf starch could be enhanced to degrade by the exogenous α- or β-amylases and the enhancing effect of the former was stronger than that of the later. 1.50 mg/ml Ca2+ improved the specific activity of the leaf (α+β)-amylase mainly due to its enhancing effect on the leaf α-amylase, and increased the starch degradation. 4 mmol/L Mn2+ inhibited the leaf α-amylase from yel owing to the early period of color-fixing and the β- and (α+β)-amylases from the yel owing to the later period of color-fixing, but enhanced the leafα-amylase from the later period of color-fixing to the later period of stem-drying and the β- and (α+β)-amylases at the later period of stem-drying. Meanwhile, Mn2+ ham-pered the starch degradation during yel owing, but promoted it from the early period of color-fixing to stem-drying. 1 mg/ml K+ enhanced the leaf α-, β- and (α+β)-amy-lases during the yel owing stage, but lowered them from the early period of color-fix-ing to the later period of stem-drying, and always inhibited the leaf starch degrada-tion. [Conclusion] The exogenous α-, β- amylases and Ca2+ of suitable concentra-tions could be used to treat the tobacco leaves before flue-curing to improve the leaf starch degradation during the curing.
基金the National Natural Science Foundation of China(No.597361 30 )
文摘A seed is the carrier of life,and research on the heat and mass transfer of a seed has already stridden toward the level of microcosm,such as cell protoplasm,cell organism,and molecular membrane.By means of a transmission electron microscope,the authors of this paper observed the microstructure of cotyledon tissue slices of the Chinese cabbage seed with a moisture content of 13% (on dry basis) and that with a moisture content of 4.3% (on dry basis) for drying 2 h at 45 ℃.The compared result was that only wrinkles had been discovered on the cell walls of the seed dried for 2 h,without any significant change for other organelles.Study on the enzyme activity shows that after a germination for 48 h,the relative activity of α amylase of the Chinese cabbage seed dried for 2 h at 45 ℃,decreased by 5.8%,whereas that of the seed dried 2 h at a temperature of 67 ℃ decreased by 30.1%.This work shows that the drying factors have greatly influence on the seed microstructure,enzyme activity,which is directly positive to seed viability.Combined with the analysis of the critical safe drying temperature of the vegetable seed,it can be concluded that enzyme activity is also the function of the drying temperature,the moisture content and the drying time.
文摘[Objective] The aim was to study the effect of mercury stress on seed germination and seedlings growth.[Method]using Zhengzhou 9023 as the experimental material and cultured in water,to study the effect of the germinating rate,seedling height,root length,seedling's fresh weight,the activities of peroxidase(POD)and amylase in leaf,root and germinating embryo at different concentrations of Hg2+(0.025,0.050,0.100,0.200,0.300,0.400,0.500 mmol/L).[Result]Low concentrations of Hg2+(≤ 0.10 mmol/L)have little effect on seed germination,seedling height,root length and fresh weight;high concentrations of Hg2+( 0.10 mmol/L)have significantly inhibited seed germination and seedling growth.Low concentration of Hg2+(≥ 0.025 mmol/L)could increase POD activity and inhibit the amylase activity significantly,and the effects have increased with the increasing of Hg2+ concentrations.[Conclusion]Hg2+ stress could change the activities of POD and amylase in leaf,root and germinating embryo,influence the energy and substrate supply which was required for normal metabolism of lipid oxidation,and inhibit seedling growth ultimately.
文摘Starch degradation in cells is closely associated with cereal seed germination, photosynthesis in leaves, carbohydrate storage in tuber and tuberous roots, and fleshy fruit development. Based on previously reported in vitro assays, β amylase is considered as one of the key enzymes catalyzing starch breakdown, but up to date its role in starch breakdown in living cells remains unclear because the enzyme was shown often extrachloroplastic in living cells. Recently we have shown for the first time that β_amylase is predominantly immuno_localized to plastids in living cells of developing apple fruit. But it remains to know whether this model of β_amylase compartmentation is more widespread in plant living cells. The present experiment, conducted in tuberous root of sweet potato ( Ipomea batatas Lam. cv. Xushu 18) and via immunogold electron_microscopy technique, showed that β amylase visualized by gold particles was predominantly localized in plastids especially at periphery of starch granules, but the gold particles were scarcely found in other subcellular compartments, indicating that the enzyme is subcellularly compartmented in the same zone as its starch substrates. The density of gold particles (β amylase) in plastids was increasing during growing season, but the predominantly plastid_distributed pattern of β amylase in cells was shown unchanged throughout the tuberous root development. These data prove that the enzyme is compartmented in its functional sites, and so provide evidence to support the possible widespread biological function of the enzyme in catalyzing starch breakdown in plant living cells or at least in living cells of plant storage organs.
文摘For the last decade, low serum amylase(hypoamylasemia) has been reported in certain common cardiometabolic conditions such as obesity, diabetes(regardless of type), and metabolic syndrome, all of which appear to have a common etiology of insufficient insulin action due to insulin resistance and/or diminished insulin secretion. Some clinical studies have shown that salivary amylase may be preferentially decreased in obese individuals, whereas others have revealed that pancreatic amylase may be preferentially decreased in diabetic subjects with insulin dependence. Despite this accumulated evidence, the clinical relevance of serum, salivary, and pancreatic amylase and the underlying mechanisms have not been fully elucidated. In recent years, copy number variations(CNVs) in the salivary amylase gene(AMY1), which range more broadly than the pancreatic amylase gene(AMY2A and AMY2B), have been shown to be well correlated with salivary and serum amylase levels. In addition, low CNV of AMY1, indicating low salivary amylase, was associated with insulin resistance, obesity, low taste perception/satiety, and postprandial hyperglycemia through impaired insulin secretion at early cephalic phase. In most populations, insulin-dependent diabetes is less prevalent(minor contribution) compared with insulin-independent diabetes, and obesity is highly prevalent compared with low body weight. Therefore, obesity as a condition that elicits cardiometabolic diseases relating to insulin resistance(major contribution) may be a common determinant for low serum amylase in a general population. In this review, the novel interpretation of low serum, salivary, and pancreas amylase is discussed in terms of major contributions of obesity, diabetes, and metabolic syndrome.
文摘The changes in the activity of amylase and amylase-isoenzyme and the degradation of starch and pigment of tobacco leaf during flue-curing were studied by using the electric- heated flue-curing barn designed and made by the Henan Agricultural University. The temperature and humidity of the barn were controlled automatically. The results indicated that starch in tobacco leaf decreased rapidly and leveled off after 48 h of curring, in the meantime, the content of soluble sugar increased accordingly and reached a peak at the stage of color-fixing. Both of them had a rapid-changing stage in the first 36 hours of yellowing. The changes of starch and soluble sugar contents had highly significant negative-correlation at 1 % level (rNC89 = -0.8962**, rYY85 = -0.9704**). The activity of amylase increased with the proceeding of curing and reached a peak after 36 hours of curing, then decreased. But the activity of amylase kept at a high level when the humidity of curing-environment was very low, even if the tobacco leaf had been dried. The rapid degradation of starch showed a significantly negative correlation with the increase of activity of amylase at 5 % level (rNC89 = -0.8495*, rYY85 = -0.7839*). The degradation of starch and pigment had the same regulation and had highly significant correlation at 1 % level (rNC89= 0.9649**, rYY85= 0.9428**). There were mainly three amylase-isoenzyme bands -A, B, C respectively, in tobacco leaf during flue curing. They were identified as α-AMY, β-AMY, R-AMY, and the activity of β-AMY was the highest. The changes in amylase activity and contents of starch and pigment were affected by the tobacco leaf moisture and environmental humidity during curing.
基金supported by the Project of National Key Basic Research and Development, China (Grant No. 2002CB410804)the Natural Science Foundation of Guizhou Province, China (Grant No. 20072058)the Foundation for Young Scholars Scientists of Guizhou University (Grant No. X060036), China.
文摘Two rice varieties, Xiushui 110 with high cadmium (Cd) tolerance and Xiushui 11 with low Cd tolerance were used to study the effects of Cd stress on seed germination, seedling growth and amylase activities. The low cadmium concentration had little effect on seed germination rate. However, cadmium stress could significantly inhibit plumule and radicle growth, especially for radicle growth. Germination index, vigour index, radicle length and amylase activities of Xiushui 11 decreased more significantly with the increasing cadmium level compared with Xiushui 110. The cadmium content in seedlings of Xiushui 11 was higher than that in Xiushui 110 when the cadmium concentration exceeded 5 μmol/L, which caused lower mitotic index in root tips and amylase activities, and more serious cadmium toxicity in Xiushui 11.
基金a part of the project titled ’Future Marine Technology Development’ funded by the Ministry of Oceans and Fisheries, Republic of Korea
文摘Postprandial hyperglycemia is an early indication of type 2 diabetes and the target of many anti-diabetic and anti-obesity studies.α-Glucosidase and α-amylase are the crucial factors in regulating starch digestion and glucose absorption,making them key targets for many studies to treat postprandial hyperglycemia.We studied the inhibitory activities of microalgal fucoxanthin against rat-intestinalα-glucosidase and pancreaticα-amylase along with the antidiabetic eff ect to induce diff erentiation in 3T3-L1 pre-adipocytes using Oil Red-O staining.Fucoxanthin displayed strong hindrance activities towardα-amylase in a concentration-dependent manner,with an IC50 value of 0.68mmol/L,whereas weak inhibitory activity against α-glucosidase,with an IC 50 value of 4.75 mmol/L.Fucoxanthin also considerably elevated glucose oxidase activity in 3T3-L1 cells by 31.3%at 5μmol/L.During adipocyte differentiation,fucoxanthin showed lipid accumulation in 3T3-L1 cells with no cytotoxicity up to 20μmol/L.However,fucoxanthin had no inhibitory activity on glucose-6-phosphate dehydrogenase.These results suggest that fucoxanthin might be useful for the prevention of obesity or diabetes by inhibiting carbohydrate-hydrolyzing enzymes and lipid accumulation and be utilized as an ingredient for a functional food or dietary supplement.