The effect of five fasciolicides on malate dehydrogenase activity and mortality of Fasciola gigantica, Fasciolopsis buski and Paramphistomum explanatum

1981 ◽  
Vol 55 (2) ◽  
pp. 115-122 ◽  
Author(s):  
A. J. Probert ◽  
R. K. Sharma ◽  
K. Singh ◽  
R. Saxena

ABSTRACTThe effect of oxyclozanide, hexachlorophene, nitroxynil, rafoxanide and diamphenethide on malate dehydrogenase activity of homogenates of Fasciola gigantica, Fasciolopsis buski and Paramphistomum explanatum was investigated. The ratio of oxaloacetate reduction to malate oxidation in homogenates of Fasciola gigantica, Fasciolopsis buski and P. explanatum was 4·5:1, 3·6:1 and 5·2:1 respectively. Oxyclozanide and rafoxanide at 10−3 M inhibited enzyme activity by 100% in homogenates from all three species while hexachlorophene at 10−3M also caused 100% inhibition in homogenates from Fasciola gigantica and P. explanatum but only 65% of malate oxidation in Fasciolopsis buski homogenates. Nitroxynil at 10−3M produced 60% inhibition in F. buski homogenates yet had little effect at this concentration on preparations from the other species. Little inhibition was seen with diamphenethide, even at high concentrations. Rapid death of Fasicola gigantica and P. explanatum resulted in vitro when 10−3M oxyclozanide, hexachlorophene, nitroxynil or rafoxanide, were added to the incubation medium. Fasciolopsis buski was killed by 10−3M oxyclozanide but at this concentration the remaining compounds only caused reduced activity. Assay of malate dehydrogenase following drug treatment in vitro failed to show any appreciable reduction in enzyme activity in Fasciola gigantica and P. explanatum but oxyclozanide and hexachlorophene produced inhibition in Fasciolopsis buski. The mode of action of these compounds is discussed.

Parasitology ◽  
1973 ◽  
Vol 67 (2) ◽  
pp. 197-204 ◽  
Author(s):  
Madan M. Goil

Biochemical studies on the non-specific phosphomonoesterases have demonstrated the presence of acid phosphomonoesterase with maximum activity at pH 4·0 in Gastrodiscus aegyptiacus (enzyme I) and at pH 4·5 in the case of Fasdolopsis buski (enzyme II). The Km for ρ-nitrophenyl phosphate hydrolysis was 0·66 mM for enzyme I and 1·1 mM for enzyme II. Different concentrations of fluoride, arsenate, tartrate, tartaric acid, cysteine and copper brought about inhibition of both enzymes and magnesium, iodoaeetate, iodoacetamide and EDTA had no influence on either enzyme activity. Cobalt activated both enzymes while zinc inhibited enzyme I and strongly stimulated enzyme II.


1980 ◽  
Vol 58 (6) ◽  
pp. 1052-1059 ◽  
Author(s):  
B. Rutti ◽  
B. Schlunegger ◽  
W. Kaufman ◽  
A. Aeschlimann

Tick (Amblyomma hebraeum) salivary glands are a rich source of Na,K-ATPase (EC 3.6.1.3), the fundamental properties of which are similar to those of Na,K-ATPases from other sources. Inhibition of the enzyme by ouabain is quantitatively similar to the inhibition of fluid secretion by this drug. Harmaline at high concentrations also inhibited the Na,K-ATPase. The nucleotides GTP, ITP, and UTP were utilized as substrates, but all were less effective than ATP. Noradrenaline, dopamine, and phenoxybenzamine, all at concentrations known to influence fluid secretion in vitro, had no effect on enzyme activity.


2000 ◽  
Vol 350 (3) ◽  
pp. 671-676 ◽  
Author(s):  
Zhen-Zhong ZHANG ◽  
Satoru NIRASAWA ◽  
Yoshiaki NAKAJIMA ◽  
Michiteru YOSHIDA ◽  
Kiyoshi HAYASHI

An aminopeptidase from Vibrio proteolyticus was translated as a preproprotein consisting of four domains: a signal peptide, an N-terminal propeptide, a mature region and a C-terminal propeptide. Protein expression and analysis of the activity results demonstrated that the N-terminal propeptide was essential to the formation of the active enzyme in Escherichia coli. Urea dissolution of inclusion bodies and dialysis indicated that the N-terminal propeptide could facilitate the correct folding of the enzyme in vitro. Using l-Leu-p-nitroanilide as the substrate, the kinetic parameters (kcat and Km) of the pro-aminopeptidase and processed aminopeptidases were analysed. The results suggested that the N-terminal propeptide inhibited enzyme activity of the mature region. In contrast, the C-terminal propeptide did not show evidence of forming an active enzyme, of correctly folding in vitro or of inhibiting the active region.


2018 ◽  
Vol 52 (3) ◽  
pp. 189-198 ◽  
Author(s):  
Rafael Simões Gonçalves ◽  
Polliana Mendes Candia Scaffa ◽  
Marina Ciccone Giacomini ◽  
Cristina de Mattos Pimenta Vidal ◽  
Heitor Marques Honório ◽  
...  

The effect of sodium trimetaphosphate (STMP) as an antiproteolytic and remineralizing agent on demineralized dentin was evaluated in vitro. The inhibitory potential of STMP at 0.5, 1.5, 3.5, and 5% against recombinant matrix metalloproteinases (MMPs) MMPs-2 and -9 was assessed by zymography. To investigate its remineralization potential, 40 bovine root specimens were obtained and subjected to a demineralization protocol to produce caries-like dentin lesions. After that, dentin surfaces were divided into 3 areas: (1) mineralized (no treatment); (2) demineralized; and (3) demineralized/treated with STMP and submitted to a pH-cycling associated or not with STMP (1.5, 3.5, or 5% STMP, 10 min of treatment). After that, superficial hardness (SH) and cross-sectional hardness (CSH) were determined. Polarized light microscopy (PLM) was used to qualitatively evaluate mineralization within the caries-like lesions. The zymographic analysis showed that STMP solution is a potent inhibitor of the gelatinolytic activity of MMPs-2 and -9 depending on the dose, since the lowest concentration (0.5%) partially inhibited the enzyme activity, while the higher concentrations completely inhibited enzyme activity. Regarding remineralization effect, only 1.5% STMP solution enhanced both the SH and CSH. PLM showed that the area treated with 1.5% STMP presented similar birefringence as mineralized sound dentin. In conclusion, 1.5% STMP solution is effective as an antiproteolytic agent against MMPs and promotes dentin remineralization.


2000 ◽  
Vol 40 (3) ◽  
pp. 206-215 ◽  
Author(s):  
B K Logan ◽  
A W Jones

The concentration of ethanol in blood, breath or urine constitutes important evidence for prosecuting drunk drivers. For various reasons, the reliability of the results of forensic alcohol analysis are often challenged by the defence. One such argument for acquittal concerns the notion that alcohol could be produced naturally in the body, hence the term ‘auto-brewery’ syndrome. Although yeasts such as Candida albicans readily produce ethanol in-vitro, whether this happens to any measurable extent in healthy ambulatory subjects is an open question. Over the years, many determinations of endogenous ethanol have been made, and in a few rare instances (Japanese subjects with very serious yeast infections) an abnormally high ethanol concentration (<80 mg/dl) has been reported. In these atypical individuals, endogenous ethanol appeared to have been produced after they had eaten carbohydrate-rich foods. A particular genetic polymorphism resulting in reduced activity of enzymes involved in hepatic metabolism of ethanol and a negligible first-pass metabolism might explain ethnic differences in rates of endogenous ethanol production and clearance. Other reports of finding abnormally high concentrations of ethanol in body fluids from ostensibly healthy subjects suffer from deficiencies in study design and lack suitable control experiments or used non-specific analytical methods. With reliable gas chromatographic methods of analysis, the concentrations of endogenous ethanol in peripheral venous blood of healthy individuals, as well as those suffering from various metabolic disorders (diabetes, hepatitis, cirrhosis) ranged from 0–0.08 mg/dl. These concentrations are far too low to have any forensic or medical significance. The notion that a motorist's state of intoxication was caused by endogenously produced ethanol lacks merit.


Blood ◽  
1983 ◽  
Vol 62 (4) ◽  
pp. 808-814
Author(s):  
H Muchi ◽  
Y Yamamoto

Three cases of uncommon childhood hematologic disorders are reported. At presentation, one patient had refractory anemia with an excess of blasts (RAEB) with partial 7-monosomy and was reclassified into RAEB “in transformation” thereafter. Another case was diagnosed as acute myelogenous leukemia with complete 7-monosomy. The other case was diagnosed as RAEB “in transformation” without chromosome aberrations. The cytogenetic studies of the patients with 7-monosomy revealed abnormal karyotypes on bone marrow cells, but normal karyotypes on peripheral blood cells. Polymorphonuclear cells from the two patients with 7-monosomy revealed reduced mitochondrial malate dehydrogenase activity, but those from the patient with RAEB “in transformation” without chromosome aberrations did not. Cytoplasmic malate dehydrogenase activity, having been defined as located on chromosome 2, was within the normal range in those three patients. The decreased mitochondrial enzyme activity in the two patients with 7-monosomy would be a dosage effect of the chromosome aberration, but not caused by their hematologic disorders. The level of mitochondrial enzyme activity in the patients with 7-monosomy was reduced in polymorphonuclear cells, but not in mononuclear cells in peripheral blood. This fact would indicate that such chromosome evolution had involved myeloid cells only, but not lymphoid cells. Both enzymes from leukemic cells of four patients with active disease revealed much higher activities than controls, an expression of partially enhanced oxidative phosphorylation.


1991 ◽  
Vol 65 (3) ◽  
pp. 187-192 ◽  
Author(s):  
P. Dubinský ◽  
B. Rušcinová ◽  
S. L. Hetmanski ◽  
C. Arme ◽  
L. Turčeková ◽  
...  

ABSTRACTThe activities of selected enzymes of carbohydrate metabolism were measured in tetrathyridia of Mesocestoides corti and in adult females and males of Heterakis spumosa. When the species were compared, only lactate dehydrogenase and phosphoenolphyruvate carboxykinase activities were considerably higher in M. corti. Activities of other enzymes were higher in H. spumosa, with malate dehydrogenase activity being considerable so. In H. spumosa, enzyme activity was higher, and succinate dehydrogenase markedly so in males, when compared with females. Tetrathyridia aged 170 and 210 days show relatively stable malate and lactate dehydrogenase activities, and mice of ICR and BALB/c strains are suitable for the maintenance of tetrathyridia.


1999 ◽  
Vol 340 (2) ◽  
pp. 491-495 ◽  
Author(s):  
Charles R. HIPKIN ◽  
Mansour A. SALEM ◽  
Deborah SIMPSON ◽  
Stephen J. WAINWRIGHT

A novel enzyme that catalyses the oxygen-dependent oxidation of 3-nitropropionic acid (3NPA) to malonate semialdehyde, nitrate, nitrite and H2O2 has been purified from leaf extracts of the horseshoe vetch, Hippocrepis comosa, and named 3NPA oxidase. The enzyme is a flavoprotein with a subunit molecular mass of 36 kDa containing 1 molecule of FMN and exhibits little specificity for all nitroalkanes tested other than 3NPA (apparent Km 620 μM). The maximum enzyme activity in vitro was expressed at pH 4.8 and was inhibited strongly by the products nitrate and nitrite. 3NPA oxidase activity was detected in green shoots, which also contain high concentrations of 3NPA, from plants grown with nitrate, ammonium or N2 as sources of nitrogen. Enzyme activity was absent from roots and cell cultures, neither of which accumulate high levels of 3NPA.


1983 ◽  
Vol 210 (1) ◽  
pp. 207-214 ◽  
Author(s):  
S Passarella ◽  
E Marra ◽  
S Doonan ◽  
E Quagliariello

1. It was previously shown [Passarella, Marra, Doonan & Quagliariello (1980) Biochem. J. 192, 649-658] that, when mitochondrial malate dehydrogenase from rat liver is incubated with sulphite-loaded mitochondria from the same source, uptake of the enzyme occurs, as judged by a fluorimetric assay of intramitochondrial enzyme activity. Confirmation of sequestration of the enzyme inside the organelles is provided by its proteinase-resistance after uptake. 2. Enzyme uptake into mitochondria is inhibited by enzyme treatment with mersalyl at concentrations that do not affect its catalytic activity. 3. Enzyme uptake is energy-dependent, as shown by inhibition of the process by carbonyl cyanide p-trifluoromethoxyphenylhydrazone and by antimycin. ATP and oligomycin, on the other hand, both stimulate the process, but stimulation by ATP is inhibited by oligomycin. These results suggest that uptake depends on maintenance of transmembrane ion gradient rather than direct ATP involvement. 4. Measurements of delta psi by means of the ‘redistribution signal’ probe safranine suggest no dependence of malate dehydrogenase uptake on membrane potential. 5. Comparison of the effects of the ionophores valinomycin, nonactin, gramicidin and nigericin shows that uptake depends on maintenance of a transmembrane pH gradient.


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