Increase In Acid Phosphatase Activity Research Articles

Aluminium induced acid phosphatase activity in roots of Al-sensitive and Al-tolerant barley varieties

In barley roots significant increase of acid phosphatase activity was observed during Al treatment. Especially steep increase was found in the roots of Al-sensitive cv. Alfor treated with Al in the range of 1–10mM which was followed by sudden decline when higher concentration (10–100mM) was applied. Continual, but significantly lower increase in phosphatase activity was also demonstrated in the roots of Al-tolerant cv. Bavaria in the range of 1–50mM Al. In both cases, Al-induced increase of acid phosphatase activity was accompanied by the increase in the amount of one phosphatase isoforme. Contrary to cv. Alfor where Al-induced changes reached their maximum in the first day of Al treatment in the Al-tolerant cv. Bavaria slight increase continued also on the second day of Al treatment. Our results indicate that different behaviour of acid phosphatase enzyme in barley cultivars during Al stress may play an important function in coping by the plants with Al induced phosphate deficiency syndrome.

Inhibitory Effect of Marine Alga Sargassum horneri Extract on Bone Resorption in Tissue Culture in Vitro.

The effect of marine alga Sargassum horneri extracts on bone resorption in vitro was investigated. Femoral-diaphyseal and -metaphyseal tissues obtained from normal rats were cultured for 48 hr in Dulbecco's modified Eagle's medium (high glucose, 4.5%) supplemented with antibiotics and bovine serum albumin. The experimental cultures contained water-solubilized extracts (10, 25, and 50 μg/ml of medium) of S. horneri. The bone-resorbing factors parathyroid hormone (1-34) (PTH; 10-7 M) and prostaglandin E2 (PGE2; 10-5 M) caused a significant decrease in the diaphyseal and metaphyseal calcium content. The decrease in bone calcium content induced by PTH or PGE2 was completely inhibited by water-solubilized extracts (10, 25, and 50 μg/ml) of S. horneri. In addition, these extracts (25 and 50 μg/ml) completely prevented the PTH (10-7 M)- or PGE2 (10-5 M)-induced increase in medium glucose consumption and lactic acid production by bone tissues. Moreover, S. horneri extracts (10-50 μg/ml) blocked PTH (10-7 M)- increased acid phosphatase activity in the diaphyseal and metaphyseal tissues. These findings indicate that water-solubilized extracts of S. horneri have a direct inhibitory effect on bone resorption in tissue culture in vitro.

Chronic Low-Dose Methylmercury Administration Decreases Mitochondrial Enzyme Activities and Induces Myopathic Changes in Rats.

Methylmercury (MeHg)-induced neurotoxicity includes skeletal muscle symptoms (muscle weakness and wasting, muscle cramp). In this study the effects of long-term low dose exposure to MeHg on skeletal muscle were investigated using rats which had received food containing MeHg (5 ppm Hg; the average intake: 200 μg Hg/kg/day). From six months after the first MeHg administration, total mercury levels in the skeletal muscle remained almost stable at 3.5-5.5 μg/g, about one tenth of the levels achieved in the acute MeHg-intoxicated model receiving 5 mg MeHgCl/kg/day for 12 days. However low-dose, long-term administration of MeHg induces histochemical changes similar to those in the acute model with decreases in mitochondrial electron transport system enzyme activities. The results indicate that even low dose MeHg administration causes disturbances in mitochondrial enzyme activities if the administration continues long term. In rats treated with MeHg for 21 months, mild myopathic changes appeared: variations in fiber size, increases in central nuclei and an increase of acid phosphatase activity. The declining function of the redox system in skeletal muscle during aging may accentuate the effects of chronic MeHg intoxication on skeletal muscle.

Cellular uptake, cytotoxicity and DNA-binding studies of the novel imidazoacridinone antineoplastic agent C1311.

C1311 is a novel therapeutic agent with potent activity against experimental colorectal cancer that has been selected for entry into clinical trial. The compound has previously been shown to have DNA-binding properties and to inhibit the catalytic activity of topoisomerase II. In this study, cellular uptake and mechanisms by which C1311 interacts with DNA and exerts cytotoxic effects in intact colon carcinoma cells were investigated. The HT29 colon cancer cell line was chosen to follow cellular distribution of C1311 over a time course of 24 h at drug concentrations that just inhibited cell proliferation by 50% or 100%. Nuclear uptake of C1311 and co-localization with lysosomal or mitochondrial dyes was examined by fluorescence microscopy and effects on these cellular compartments were determined by measurement of acid phosphatase levels, rhodamine 123 release or DNA-binding behaviour. The strength and mode of DNA binding was established by thermal melting stabilization, direct titration and viscometric studies of host duplex length. The onset of apoptosis was followed using a TUNEL assay and DNA-fragmentation to determine a causal relationship of cell death. Growth inhibition of HT29 cells by C1311 was concomitant with rapid drug accumulation in nuclei and in this context we showed that the compound binds to duplex DNA by intercalation, with likely A/T sequence-preferential binding. Drug uptake was also seen in lysosomes, leading to lysosomal rupture and a marked increase of acid phosphatase activity 8 h after exposure to C1311 concentrations that effect total growth inhibition. Moreover, at these concentrations lysosomal swelling and breakdown preceded apoptosis, which was not evident up to 24 h after exposure to drug. Thus, the lysosomotropic effect of C1311 appears to be a novel feature of this anticancer agent. As it is unlikely that C1311-induced DNA damage alone would be sufficient for cytotoxic activity, lysosomal rupture may be a critical component for therapeutic efficacy. © 1999 Cancer Research Campaign

Acid phosphatase activity in phosphorus‐deficient white lupin roots

White lupin (Lupinus albus L.) develops proteoid roots when grown in phosphorus (P)‐deficient conditions. These short, lateral, densely clustered roots are adapted to increase P availability. Previous studies from our laboratory have shown proteoid roots have higher rates of non‐photosynthetic carbon fixation than normal roots and altered metabolism to support organic acid exudation, which serves to solubilize P in the rhizosphere. The present work indicates that proteoid roots possess additional adaptations for increasing P availability and possibly for conserving P in the plant. Roots from P‐deficient (–P) plants had significantly greater acid phosphatase activity in both root extracts and root exudates than comparable samples from P‐sufficient (+P) plants beginning 10 d after emergence. The increase in activity in –P plants was most pronounced in the proteoid regions. In contrast, no induction of phytase activity was found in –P plants compared to +P plants. The number of proteoid roots present was not affected by the source of phosphorus supplied, whether organic or inorganic forms. Adding molybdate to the roots increased the number of proteoid roots in plants supplied with organic P, but not inorganic P. Increased acid phosphatase activity was detected in root exudates in the presence of organic P sources. Native‐polyacrylamide gel electrophoresis demonstrated that under P‐deficient conditions, a unique isoform of acid phosphatase was induced between 10 and 12 d after emergence. This isoform was found not only within the root, but it comprised the major form exuded from proteoid roots of –P plants. The fact that exudation of proteoid‐root‐specific acid phosphatase coincides with proteoid root development and increased exudation of organic acids indicates that white lupin has several coordinated adaptive strategies to P‐deficient conditions.

Effects of Azinphosmethyl on Some Biochemical Parameters in Blood, Muscle, and Liver Tissues ofCyprinus carpio(L.)

In the present study, the effects of 0.20 and 0.35 ppm azinphosmethyl exposures occurring on days 1, 2, 3, 4, and 15 for on serum enzyme activities and protein and glucose levels in blood, muscle, and liver tissues of fish,Cyprinus carpio(L.), were photometrically investigated. Protein and glycogen contents in muscle and liver tissues were also determined. Azinphosmethyl did not affect the level of total protein in serum. However, there was a decrease in the level of muscle protein in 2 days of treatement while the liver protein elevated after acute exposure to both concentration of azinphosmethyl. It was also found that there was an elevation in the serum glucose content while the muscle and liver glycogen contents were reduced. Serum enzyme activities were also altered. Glutamate-oxaloacetate transaminase and glutamate-pyruvate transaminase activities initially increased following exposure to both concentrations of azinphosmethyl; later there was no change in the activities of these enzymes. Lactate dehydrogenase enzyme activity also increased in the beginning of the experiment, but it was at the control level in 15 days. Alkaline phosphatase enzyme activity decreased on the first of day treatment while it increased second day. However, there was no significant difference during the other exposure times. After acute exposure to 0.35 ppm concentration of azinphosmethyl there was a significant increase in acid phosphatase activity while there was no change in this enzyme activity at the other exposure concentration and periods. Furthermore, sublethal concentrations of azinphosmethyl caused the behavioral and morphological changes inC. carpio.The results of this study showed that tissue necrosis and an elevation of glycogenolysis occurred following acute exposure to azinphosmethyl, but compensatory mechanisms were developed byC. carpioduring chronic exposure.

Myopathy Induced by HMG–CoA Reductase Inhibitors in Rabbits: A Pathological, Electrophysiological, and Biochemical Study

A combination of electrophysiological, pathological, and biochemical studies were performed in myopathy induced by 3-hydroxy-3-methylglutaryl–coenzyme A (HMG–CoA) reductase inhibitors. Simvastatin (a lipophilic inhibitor) or pravastatin (a hydrophilic inhibitor) were administered by gavage to rabbits. In Group I (simvastatin-treated group, 50 mg/kg/day for 4 weeks), four rabbits showed muscle necrosis and high serum creatine kinase (CK) levels, and all six rabbits showed electrical myotonia. In Group II (pravastatin-treated group, 100 mg/kg/day for 4 weeks), no rabbit showed either condition. In Group III (pravastatin-treated group, 200 mg/kg/day for 3 weeks plus 300 mg/kg/day for 3 weeks), one rabbit showed muscle necrosis and high serum CK level and two rabbits showed electrical myotonia. The pathological findings were muscle fiber necrosis and degeneration with increased acid phosphatase activity by light microscopy, autophagic vacuoles and mitochondrial swelling, and disruption and hypercontraction of myofibrils by electron microscopy. Ubiquinone content decreased in skeletal muscle by 22 to 36% in Group I, by 18 to 52% in Group II, and by 49 to 72% in Group III. However, mitochondrial enzyme activities of respiratory chain were normal in all groups. These results indicate that myopathy was not induced by a secondary dysfunction of mitochondrial respiration due to low ubiquinone levels.

Accumulation of tau in autophagic vacuoles in chloroquine myopathy.

Long-term administration of chloroquine to rats induces a vacuolar myopathy, which is specifically termed chloroquine myopathy (CM). In CM, tau mRNA levels were transiently upregulated in the early phase, while tau itself slowly accumulated in the late phase. The temporal profiles of tau mRNA levels and its accumulation were very similar to those of beta-amyloid protein precursor (APP) and its carboxyl-terminal fragments, both of which have been known to be degraded in lysosomes. Immunocytochemistry showed that tau progressively accumulated in the rimmed vacuoles exhibiting increased acid phosphatase activities, and immunoelectron microscopy demonstrated that tau was located within autophagic vacuoles. These results suggest that the accumulation of tau in CM is due to defective tau degradation in the lysosomal compartment in the muscle.

EXERCISE INDUCED DELAYED ONSET MUSCLE DAMAGE, SORENESS AND MUSCLE FUNCTIONAL CHANGES FOLLOWING ECCENTRIC EXERCISE 362

The purpose of this study was to observe changes of muscle function, muscle soreness (MS) and delayed onset muscle damage (DOMD) in 9 college athletes following 200 continuous standing broad jumps. Knee extension and flexion ability were tested isokinetically.Perceptive muscle soreness ratio indicated MS appeared 18 hours post exercise (PE), and peaked between 24 to 48 hours PE. Muscle damage was confirmed by light and electron microscopy from muscle biopsy 48 hours PE. Significant quadriceps strength loss was noted immediately, 3, 24 and 48 hours PE by isometric and isokinetic test at speed of 60°, 180° and 300°/S. In addition to the blood chemistry results below, increased acid phosphatase activity, calcium level, and WBC accumulation were noted in some degenerated muscle fibers after 48 hours PE. This study supported that there were secondary injury factors during PE periods, which enhance the exercise induced microdamage to DOMD.Table

Characterization of the amsI gene product as a low molecular weight acid phosphatase controlling exopolysaccharide synthesis of Erwinia amylovora

The ams region, responsible for amylovoran synthesis of the fireblight pathogen Erwinia amylovora, contains the gene amsI encoding a 144 amino acid protein with homology to mammalian low molecular weight acid phosphatases [Bugert and Geider (1995) Mol. Microbiol. 15, 917–933]. A DNA fragment with amsI was cloned under the control of the lac promoter on a high copy number plasmid. The gene product of amsI is about 17 kDa in a protein expression system and had the enzymatic activity of an acid phosphatase. This is the first report about a low molecular weight acid phosphatase activity in prokaryotes. As part of the large ams transcript, expression of amsI was affected by the activator proteins RcsA and RcsB. Overexpression of amsI in E. amylovora caused a strong increase of acid phosphatase activity, but additionally a strong reduction in EPS synthesis, phenotypically similar to a mutation in the gene. The gene product may participate in changes of phosphorylation required for the biosynthesis of EPS such as recycling the lipid carrier diphosphate to the monophosphate form.

Properties of secretory acid phosphatase from lupin roots under phosphorus-deficient conditions

Phosphorus deficiency induces the synthesis of acid phosphatases in roots of lupin and other plant species. In this study we examined the induction of secretory acid phosphatase (S-APase) at both the molecular and cellular levels. Lupin plants had increased levels of total acid phosphatase activity within two to five days after P was withered and levels approximately doubled by 15 days. Lateral roots and not main tap roots were responsible for this increase in acid phosphatase activity. Immunoblot analysis using antibodies raised against a purified S-APase showed that the synthesis of this protein was induced as early as 2 days in the P deficient treatment and that levels dramatically increased by 15 days. In contrast, no immunoreactive polypeptide was evident from crude extracts prepared from root tissues of—P treated plants. Immunocytochemical analysis revealed that the protein was located on the surface of epidermal cells of main tap roots and in the cell walls and intercellular spaces of lateral roots and lateral roots may actively secrete S-APase as soon as it is synthesized. A cDNA clone encoding the S-APase was isolated from a cDNA library constructed from lupin roots grown without P. The clone was 2,187 bp in length and had a single open reading frame of 637 amino acid residues. The deduced amino acid sequence was identical to the N-terminal region and peptide sequences of S-APase purified from lupin roots. A hydrophobic signal peptide region consisted of 31 amino acids. The primary structure was highly homologous to iron-zinc purple acid phosphatase from Phaseolus vulgaris (76%), secretory purple acid phosphatase from Arabidopsis thaliana (71%), and two Aspergillus phosphate repressible acid phosphatases (59% and 58%).

Programmed cell death during metamorphosis in the blow-fly Calliphora vomitoria.

During metamorphosis, the salivary glands of the blow-fly undergo programmed cell death. Data is presented indicating that this programmed cell death does not in many respects emulate classical apoptosis. The cells are seen to vacuolate and swell rather than condense and shrink. There appears to be a transient enhancement in autophagy and an increase in acid phosphatase activity. This is followed by the characteristic appearance of ribosomal and extracisternal sources of the enzyme leading to autolysis. There appears to be no lysosomal leakage of acid phosphatase. As in apoptosis, the mitochondria persist until the cell fragments. The nucleus, however, does not show the distinct chromatin margination and blebbing that is typical of apoptosis. These changes are compared with necrotic changes induced by experimental anoxia. Overall the results show that a programmed cell death distinct from classical apoptosis is taking place.

Induction of differentiation and down-regulation of c- myb gene expression in ML-1 human myeloblastic leukemia cells by the clinically effective anti-leukemia agent meisoindigo

Meisoindigo, a second generation derivative of indirubin, is an effective chemotherapeutic agent with very low toxicity used in the treatment of chronic myeloid leukemia. To determine the nature of this activity, the effect of a nontoxic concentration (0.72 μg/mL) of this compound on ML-1 human myeloblastic leukemic cells was examined. At such a concentration, differentiation induction was found to be the most pronounced drug effect. During the 3-day drug incubation period, the viable cell number remained essentially constant, with approximately 48% of the cells demonstrating a mature phenotype with increased acid phosphatase activity and nitroblue tetrazolium dye reduction. As observed with other DNA-specific agents, induction of ML-1 differentiation by meisoindigo was accompanied by the down-regulation of c- myb gene expression. These data suggest that induction of leukemic cell differentiation associated with decreased c- myb expression may be one of the mechanisms of the antitumor action of meisoindigo.

Acid phosphatase activity and phosphorus nutrition in Scots pine needles.

From March to October, acid phosphatase activity and phosphorus (P) concentration were measured in four needle age classes of the upper and lower crowns of fertilized and unfertilized Scots pine (Pinus sylvestris L.) trees. Negative correlations between acid phosphatase activity and P concentration were observed in current-year needles and in needles in the upper part of the crown, whereas there was a positive correlation between enzyme activity and P concentration in older needles and in needles in the lower part of the crown. In May and October, needles of all ages showed increased acid phosphatase activity. The most sensitive response of acid phosphatase activity to phosphate supply and phosphorus status of the whole tree was seen in current-year needles on the first whorl where a 300% increase in acid phosphatase activity was observed in response to a decrease in foliar P concentration of 1.7-1.8 mg P g(DW) (-1).

Phosphorus and nitrogen fertilization of a Norway spruce forest-effects on needle concentrations and acid phosphatase activity in the humus layer

Increased atmospheric deposition of N might eventually lead to P deficiency. The relation between needle P concentration and acid phosphatase activity in the humus layer was studied during 1990–93 in a Norway spruce stand where the water and N and P supplies had been experimentally manipulated since 1988. Treatments included control (C), yearly application of ammonium sulphate (NS), N-free fertilizer (V), granulated wood ash (A), irrigation (I), drought (D) and water plus nutrients in an “optimum” combination (IF). We found indications of a feed-back mechanism for P, where low concentrations in the needles were associated with increased acid phosphatase activity in the humus layer. Acid phosphatase estimations made during moist soil conditions were much more informative than those made during dry conditions. We further argue that a site-specific “base-line” exists for acid phosphatase activity in the soil, mainly originating from enzymes immobilized in the field, but active in the assay. Increased phosphatase activity, above the base line, was generally found in the A, I and NS treatments, but in some cases also in C. Although P and N concentrations were significantly higher in the IF treatment as compared to the C and the D treatments, the P as fraction of N was 0.10 and thus balanced in all cases. In the A and I treatment P:N was around 0.09, while it was only 0.07 in the NS treatment, mainly due to high N concentrations. The latter treatment thus created an imbalanced situation where P additions most likely would have increased tree growth.

Tissue culture loading test with storage granules from animal models of neuronal ceroid‐lipofuscinosis (Batten disease): Testing their lysosomal degradability by normal and Batten cells

Storage granules (SGs) from ovine and canine models of Batten disease were found to be easily phagocytosed by four cell types studied. The cell types tested were human fibroblasts and peripheral monocytes (control and from a late infantile Batten disease patient), rat C6 cell line, and neonatal cardiomyocytes. The phagocytosed SGs elicited an increase in acid phosphatase activity which was localized in the phagolysosome. After phagocytosis SGs were followed for various times ranging from 7 to 21 days and were found to be of unchanged density (phase contrast), autofluorescence, and ultrastructural appearance. These findings point to their undergradability, or very low degree of degradability, in phagolysosomes in both normal or Batten cultured cells. The Batten disease SGs are not toxic and did not cause any adverse affect on the host cells. Either the normal clearance rate from lysosomes is too slow to be measured by this technique or subunit c accumulation in lysosomes need not result from a primary lysosomal protease defect. Subunit c may aggregate, because of the lack of some normally preventive factor, resulting in a physical barrier to the degradation of this highly apolar molecule.

Effect of the fungicide chlorothalonil (Bravo) on some metabolic activities of aquatic fungi

Physiological responses ofAchlya proliferoides, Saprolegnia ferax andDictyuchus sterilis as affected by the fungicide chlorothalonil (Bravo) were determined. Glucose consumption differed in dependence on the organisms used. Ammonia and peptide nitrogen secretion were stimulated inS. ferax but inhibited in the other two organisms. All doses of the fungicide used decreased phosphorus absorption and increased acid phosphatase activity. The lowest concentrations (30 ppm) of the fungicide increased DNA, RNA and protein synthesis while inhibition was observed at moderate or high concentrations. Aspartate aminotransferase and alanine aminotransferase activities were inhibited inA. proliferoides, stimulated inS. ferax but remained similar to that of the control inD. sterilis.

Leishmania donovani: Enhanced Expression of Soluble Acid Phosphatase in the Presence of Sinefungin, an Antiparasitic Agent

Sinefungin, an antileishmanial nucleoside, induces morphological and ultrastructural changes in promastigotes of Leishmania donovani. The most important modifications are the enlargement of the flagellar pocket and the increased activity of the Golgi apparatus. Cytoenzymatic labeling demonstrates an increased activity of the soluble acid phosphatase in the flagellar reservoir of sinefungin-treated cells. The affinity constant remained unchanged. Analyzes by Western blot demonstrate an increased amount of the enzyme in the treated cells. The increased amount was not due to impaired enzyme release, as in the external medium the acid phosphatase was also enhanced but to a lesser extent. Under identical conditions the membrane-bound acid phosphatase was not modified. These results indicate that the enlargement of the flagellar pocket is the consequence of the accumulation of acid phosphatase and other Golgi-mediated enzymes provoking unbalanced cytoplasmic exchange. Sinefungin has the same effects on Leishmania tropica promastigotes. However, these effects are not specific to sinefungin. Another molecule, taxol, also induced cell rounding accompanied by increased acid phosphatase activity. Under conditions where cell rounding is not observed, in stationary phase or with compounds which stopped proliferation without shape change, no increase in the amount of acid phosphatase could be observed. These results clearly demonstrate a correlation between morphological, ultrastructural changes and the stimulated expression of acid phosphatase.

Placenta humana chagásica: alteración estructural y citoquímica de vasos sanguíneos

Various authors have demonstrated that coronary blood vessels could llave sorne participation in the pathogenesis of the cardiac alterations of Chagas' disease. The purpose of this work vas to detect structural and cytocheniical niodifications of blood vessels in human chagasic placentas at tcrm with optical and electron microscopy due their possible participation in the pathogenesis of the congenital transmission of the disease. In twa of the six chagasic placentas at term from pregnant women with positive serology, there vas diminution and occlusion of the lumen of the chorionic vi¡¡¡ blood vessels, with hialineaspect of their walls. An increase of acid phosphatase activity in the endothelium vas also observed with electron microscopy. The diminished blood vessel lumen could be due to smooth inuscle and endothelium participation.

Inhibition of growth and increase of acid phosphatase by testosterone on androgen-independent murine prostatic cancer cells transfected with androgen receptor cDNA.

Most androgen-unresponsive prostatic cancer cells are found to lack androgen receptor (AR). To clarify the role of AR in the process of the progression from androgen-dependent to androgen-unresponsive tumor, the AR gene was transfected into an AR-negative rat prostatic cancer cell line CUB-II. AR-transfectant cells expressed AR mRNA and showed binding to R1881. AR was found in nuclei of AR-transfectant cells by histochemical examination. Therefore, AR-transfectant cells were considered to contain functional AR. The growth of AR-transfectant cells was markedly inhibited in culture in the presence of testosterone, and the effect of testosterone was reduced by simultaneous addition of flutamide. Moreover, tumors inoculated with AR-transfectant cells in male mice showed much slower growth than those in females. The tumors of AR-transfectant cells in mice consisted of slightly larger spindle-shaped cells when compared to those of CUB-II cells. Moreover, AR-transfectant cells contained a few polynuclear giant cells. Since CUB-II cells contained acid phosphatase (AcP) activity, the addition of testosterone in culture increased AcP activity of AR-transfectant cells. It is concluded that resumption of androgen-dependent processes reduces the growth rate accompanying changes of phenotype.