重金属镉对鲫鱼碱性磷酸酶和酸性磷酸酶活性的影响

研究了重金属镉对鲫鱼肠、肝胰脏、鳃组织碱性磷酸酶和酸性磷酸酶活性的影响。结果表明,在0.2、0.4、0.8mg/L镉浓度条件下静态染毒12h、24h、48h、96h后,鲫鱼肠、鳃组织中碱性磷酸酶(AKP)和酸性磷酸酶(ACP)的活性降低,肝和胰脏的碱性磷酸酶活性没有明显变化,其酸性磷酸酶活性则升高。     

镉、铅对蟾蜍精巢毒作用的酶学研究

为研究镉、铅对精巢的生化毒作用机理 ,应用氯化镉、硝酸铅溶液对成年雄性蟾蜍进行腹腔染毒 (按镉计 0 .1、0 .2、0 .4、0 .8mg/ kg体重 ;按铅计 1、2、4、8mg/ kg体重 ) ,连续染毒 7d后活体解剖 ,测定分析精巢中各种酶的活性。结果显示 ,在镉染毒下 ,精巢乳酸脱氢酶 (L DH)和酸性磷酸酶 (ACP)的活性随镉染毒剂量的增加而降低 ,而碱性磷酸酶 (AL P)未发现明显变化 ;在铅染毒下 ,乳酸脱氢酶 (L DH)和碱性磷酸酶 (AL P)的活性随铅染毒剂量的增加而降低 ,而酸性磷酸酶 (ACP)未发现明显变化 ;乳酸脱氢酶 (L DH)同工酶在镉、铅染毒下则主要表现为酶带 L DH1 、L DH2 的抑制或缺失和 L DH5活性的增强。因此 ,镉、铅对蟾蜍的雄性生殖毒性机理可能与酶的活性存在着一定的关系 ,L DH可以考虑作为反映镉、铅中毒对精巢功能影响程度的一种有价值的生化指标     

养殖半滑舌鳎肝胰、中肾、鳃、头肾、脾和心中酸性磷酸酶、碱性磷酸酶和过氧化物酶的组织化学定位

目的研究半滑舌鳎肝胰、中肾、鳃、头肾、脾和心中酸性磷酸酶(ACP)、碱性磷酸酶(ALP)和过氧化物酶(POX)的分布及组织定位。方法取健康半滑舌鳎肝胰、中肾、鳃、头肾、脾和心组织进行固定,冰冻切片后进行酶组织化学染色和光密度定量统计分析。结果 ACP活性部位为棕色,主要分布于肝胰小叶间胆管和静脉,中肾肾小体中的肾小球和肾间质的肾小管,头肾和脾中的巨噬细胞以及心肌层中,在鳃中未见有分布;ALP活性部位被染为蓝紫色,主要分布于肝胰的胰腺腺泡内,中肾肾间质的肾小管,鳃的鳃丝血管和上皮细胞,脾静脉的管壁处和椭圆体,心外膜和肌膜上以及头肾的血窦腔内皮;POX活性部位被染为茶褐色,主要分布于肝胰小静脉和肝血窦内的血细胞,中肾肾间质的血细胞,鳃的鳃丝血管、鳃小片血窦和上皮细胞,头肾、脾内的血细胞以及心的心肌层和血细胞中。ACP活性由大到小依次为心、肝胰、脾、中肾、头肾;ALP活性由大到小依次为中肾、鳃、头肾、脾、心、肝胰;POX活性由大到小依次为脾、头肾、肝胰、中肾、鳃、心。结论 ACP、ALP和POX在半滑舌鳎6种组织中分布特点不同,其活性大小在不同组织中有显著差异。     

大鼠肝大部分切除前热休克对热休克蛋白和磷酸酶的影响*

定性和定量分析了在大鼠2/3肝切除前8h热休克(46℃,30min)处理(HS-PH)的肝再生期间(0-144h)保持性热休克蛋白70/诱导性热休克蛋白68(HSC70/HSP68)分布和含量变化、酸性磷酸酶(ACP)和碱性磷酸酶(AKP)分布、种类和活性变化.并把上述结果同只进行热休克(46℃,30min)(HS)和只进行2/3肝切除(PH)时这些分子的变化进行了比较.发现三种处理均可提高ACP、AKP活性和HSC70/HSP68表达量,但它们的变化规律不同.进一步分析发现,HS-PH后ACP活性增强是与140kD酶活性增加有关,而AKP活性增强则与140和160-180kD的酶活性增加有关.根据实验结果推测,ACP、AKP和HSC70/HSP68均在肝细胞的热休克反应和肝再生中起作用;它们可能均参与这些过程中的信号传导,但ACP可能在启动肝细胞增殖中起主导作用,AKP和HSC70/HSP68可能在胞质分裂中起主导作用.     

棉铃虫中肠几种酶的组织化学研究

采用酶组织化学方法研究了棉铃虫中肠三磷酸腺苷酶、酸性磷酸酶和碱性磷酸酶的分布和活性。结果显示三种酶在棉铃虫中肠均有分布,但分布部位各不相同,其中,三磷酸腺苷酶在肠壁分泌细胞、肠壁细胞、环肌和纵肌均有分布,以肠壁分泌细胞活性较高;碱性磷酸酶主要分布于肠壁分泌细胞,在肠壁分泌细胞做绒毛处活性最高;酸性磷酸酶分布于肠壁细胞、环肌和纵肌,在肠壁细胞底膜处活性最高。这些酶可以作为棉铃虫中肠不同条件下的生理指标。     

小鼠成长过程中肾、肝、小肠碱性磷酸酶活性变化及组织细胞定位

利用比色、酶的原位复性电泳、组织化学和电镜酶化学等方法,观察了小鼠出生后的成长过程中肝、肾和小肠内碱性磷酸酶(AKP)的活性变化及组织细胞定位.结果表明,在小鼠成长过程中,3种器官内的AKP活性依次为小肠肾肝,小肠和肝AKP活性先上升后下降,肾内酶活性呈上升趋势.AKP活性在小肠主要分布在小肠绒毛上皮细胞的细胞膜、细胞浆、微绒毛和微绒毛表面的糖衣上,在肝主要分布住胆小管,在肾主要分布在皮质肾小管,尤以近曲小管的刷状缘、近曲小管上皮细胞膜和符种管状结构之间的腔隙内分布较多.小鼠成长过程中肝内共出现3条AKP同工酶带,小肠内出现2条,肾内出现3条,各同工酶活性随着小鼠的生长发育发生不同的变化.     

饥饿对草鱼非特异免疫水平的影响

研究了长期饥饿对草鱼(Ctenopharyngodon idellus)非特异性免疫水平的影响。实验选取平均体质量(31.86±1.47)g的草鱼,随机分为2个实验组(对照组和饥饿组),每组3个平行,饥饿处理15、30、45和60 d,测定饥饿对草鱼头肾和脾中自然杀伤(NK)细胞的杀伤活性、血清和肝胰脏中溶菌酶活性、血清中碱性磷酸酶活性的影响。结果表明:受饥饿胁迫的影响,草鱼自然杀伤性细胞在脾和头肾中的杀伤活性显著低于对照组(P0.05)且不随着饥饿时间的延长发生显著性变化;随着饥饿时间的延长,血清和肝胰脏中溶菌酶呈现先升高后降低的趋势,血清碱性磷酸酶在饥饿15、45、60 d时显著低于对照组;饥饿组的碱性磷酸酶活性在饥饿30 d以后,维持恒定。由此可见,长时间的饥饿胁迫降低了草鱼的免疫水平。相比较而言,自然杀伤细胞的杀伤活性在反映鱼类免疫状况时比溶菌酶和碱性磷酸酶可能更为灵敏。     

饥饿胁迫对草鱼鱼种非特异免疫力的影响

研究长期饥饿对草鱼(Ctenopharyngodon idellus)鱼种非特异性免疫力的影响。实验选取平均体质量(31.86?1.47g)的草鱼,随机分为2个实验组(对照组和饥饿组),每组三个平行,饥饿处理15、30、45和60d,测定饥饿对头肾和脾脏中自然杀伤(NK)细胞的杀伤活性、血清和肝胰脏中溶菌酶活性、血清中碱性磷酸酶活性的影响。结果表明：受饥饿胁迫的影响,草鱼鱼种自然杀伤性细胞在脾脏和头肾中的杀伤活性显著低于对照组(P<0.05)且不随着饥饿时间的延长发生显著性变化;随着饥饿时间的延长,血清和肝胰脏中溶菌酶呈现先升高后降低的趋势,血清碱性磷酸酶在饥饿15d、45d、60d时显著低于对照组;,饥饿组的碱性磷酸酶活性在饥饿30d以后,维持恒定。由此可见,长时间的饥饿胁迫降低了草鱼鱼种的免疫力。相比较而言,自然杀伤细胞的杀伤活性在评价鱼类的免疫状况时比溶菌酶和碱性磷酸酶更为灵敏。     

妊娠小鼠子宫腺细胞区的碱性磷酸酶与酸性磷酸酶的研究

小鼠子宫系膜三角区在妊娠后出现上皮样细胞群,群内的细胞称颗粒子宫腺细胞(granu-lated metriial gland cells,GMG细胞),该区改称子宫腺细胞区(metriial gland cell area,MGCA).取孕12～19天MGCA,液氮速冻,恒冷箱切片,偶氮偶联法显示碱性磷酸酶(ALP)与酸性磷酸酶(ACP).结果为,ALP主要分布于GMG细胞群间的疏松结缔组织中;GMG细胞为阴性反应.ACP主要位于GMG细胞内,群间结缔组织含量较少.两种酶的活性随胎龄增加而减弱.ALP与ACP的定位与活性变化特性显示它们与GMG细胞功能关系密切.     

高效氯氰菊酯对草鱼器官酸性磷酸酶活性的影响

研究了暴露于不同高效氯氰菊酯浓度下草鱼Ctenopharyngodon idellas鳃、肝胰脏和肾脏的酸性磷酸酶(Acid Phosphatase,ACP)的活性变化。实验中高效氯氰菊酯浓度设5组,其中对照组1个(0μg/L),处理组4个(0.5μg/L、1.0μg/L、3.0μg/L、5.0μg/L)。每组随机投放40尾草鱼,分别于1d、5d、12d取样,测定鳃、肝胰脏和肾脏的ACP活性。结果显示,鳃ACP活性低浓度(0.5μg/L、1.0μg/L)短时间(1d)暴露下显著增加(P<0.01),高浓度(3.0μg/L、5.0μg/L)暴露时显著下降(P<0.01);肝胰脏ACP活性暴露1d时,除0.5μg/L组外,其他处理组均显著下降(P<0.05、P<0.01),暴露5d、12d时,各处理组均显著上升(P<0.05、P<0.01);肾脏ACP活性除0.5μg/L组在暴露1d、5d时无显著变化(P>0.05)外,其他处理组在暴露时间内均显著下降(P<0.01)。实验表明:高效氯氰菊酯能够通过影响草鱼鳃、肝胰脏和肾脏中酶的活性,干扰这些器官的代谢平衡,进而对这些器官产生毒害作用。     

Carcinoplacental Alkaline Phosphatase

Using HeLa TCRC-1, a cell line which is monophenotypic with respect to the Regan isoenzyme of alkaline phosphatase, we have examined the factors which influence its expression in relation to events of the cell cycle.
DNA synthesis is not required for hormone induction of the Regan isoenzyme as in the presence of hydroxyurea, a specific inhibitor of DNA synthesis, we found induction to occur. Additionally, when partially synchronised cells were allowed to leave the S period prior to hormone treatment, and hydroxyurea was added to prevent cells from entering the next S period, hormone induction of the Regan isoenzyme was still observed. This indicates that initiation of expression of hormone-induced carcinoplacental alkaline phosphatase occur prior to the DNA synthetic phase of the cell cycle.
We propose a hypothetical two-step mechanism of hormone induction to interpret the present findings in relation to previous results.     

Rhizobiales-like Phosphatase 2 from Arabidopsis thaliana Is a Novel Phospho-tyrosine-specific Phospho-protein Phosphatase (PPP) Family Protein Phosphatase

Cellular signaling through protein tyrosine phosphorylation is well established in mammalian cells. Although lacking the classic tyrosine kinases present in humans, plants have a tyrosine phospho-proteome that rivals human cells. Here we report a novel plant tyrosine phosphatase from Arabidopsis thaliana (AtRLPH2) that, surprisingly, has the sequence hallmarks of a phospho-serine/threonine phosphatase belonging to the PPP family. Rhizobiales/Rhodobacterales/Rhodospirillaceae-like phosphatases (RLPHs) are conserved in plants and several other eukaryotes, but not in animals. We demonstrate that AtRLPH2 is localized to the plant cell cytosol, is resistant to the classic serine/threonine phosphatase inhibitors okadaic acid and microcystin, but is inhibited by the tyrosine phosphatase inhibitor orthovanadate and is particularly sensitive to inhibition by the adenylates, ATP and ADP. AtRLPH2 displays remarkable selectivity toward tyrosine-phosphorylated peptides versus serine/threonine phospho-peptides and readily dephosphorylates a classic tyrosine phosphatase protein substrate, suggesting that in vivo it is a tyrosine phosphatase. To date, only one other tyrosine phosphatase is known in plants; thus AtRLPH2 represents one of the missing pieces in the plant tyrosine phosphatase repertoire and supports the concept of protein tyrosine phosphorylation as a key regulatory event in plants.     

Phosphatase from Proteus mirabilis

Cell-free preparations of Proteus mirabilis contained a phosphatase (EC 3.1.3.1), whose activity surpassed that of alkaline phosphatase from Escherichia coli. Phosphatase was also found in the culture liquid of P. mirabilis. The composition of proteins displaying enzyme activity was assayed by polyacrylamide gel electrophoresis. Enzyme synthesis was studied at various stages of bacterial growth. Biosynthesis of phosphatase in P. mirabilis (similarly to that in other bacteria) was shown to be induced under conditions of inorganic phosphate deficiency in the medium.     

Phosphatase from Proteus mirabilis

Cell-free preparations of Proteus mirabiliscontained a phosphatase (EC 3.1.3.1) whose activity surpassed that of alkaline phosphatase from Escherichia coli. Phosphatase was also found in the culture liquid of P. mirabilis. The composition of proteins displaying enzyme activity was assayed by polyacrylamide gel electrophoresis. Enzyme synthesis was studied at various stages of bacterial growth. Biosynthesis of phosphatase in P. mirabilis(similarly to that found in other bacteria) was shown to be induced under conditions of inorganic phosphate deficiency in the medium.     

Phosphatase production byAspergillus ficuum

Summary Effects of nutritional and cultural conditions on cell growth and phosphatase production byAspergillus ficuum were studied.A. ficuum produced high levels of phosphatases when grown on a basal medium that contained a minimal amount (2 mg/100 ml) of phosphorus in an acidic growth medium. The organism produced a nonspecific acid phosphomonoesterase rather than phytin-specific phosphatase. The enzyme hydrolyzed a variety of phosphates and produced orthophosphate. The rate of phosphate hydrolysis was dependent on the pH of the reaction, where the pH optimum for acid phosphatase was 2.5 and that for phytase was 5.0. The organism slowly released the phosphatase, and the enzyme activity in the growth medium increased continually during a one-month growth period. For a high level of phosphatase production, low levels (1–5 mg%) of initial phosphorus were necessary and polyphosphates were the desired form rather than the monophosphate. The addition of surfactants, such as polyoxyethylene ethers and sodium oleate, to fungal culture medium markedly increased the level of phosphatase production.