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The studies were carried out on dispersed acini prepared from pancreas of guinea pigs infected with 5000 invasive eggs of Ascaris suum. The basal amylase secretion and that stimulated with acetylcholine and carbachol or blocked with atropine was determined. The basal secretion of amylase was significantly higher in pancreatic acini isolated from infected animals. The stimulation by acetylcholine and carbachol of these acini was weaker than in the control group. These results suggest that cholinergic stimulation of pancreatic amylase secretion was changed during larval ascaridosis.
The studies were carried out on pancreas extracts from guinea pigs free of parasite invasion. The activity of trypsin was determined according to the method of Anson, and amylase of Fennel method. The measurements of activity were done at the presence of homogenized invasive eggs of Ascaris suum, and the mixture of volatile organic acids C₂-C₆ (at concentrations of 30.3 and 0.3 mM/l). In samples with homogenized invasive eggs of A. suum the amylase activity remained unchanged while the activity of trypsin was considerably higher (p < 0,01). The introduction of the organic acids at conc. 30 mM/l into the samples was the reason of lower amylase activity. No influence of these acids on trypsin activity in pancreas extracts was observed.
The activity of alpha-amylase in the experimental groups of guinea pigs was lower than in control animals. The decreased level of activity of trypsin was noted (p<0.05) also in infected animals, and in treatment with organic acids. In the group of guinea pigs, which was administrated homogenized eggs of parasite, the activity of enzyme was a little higher than in control animals. The infection of animals was associated with increase of relative weight, of lungs. The guinea pigs treatment with organic acids had also a higher weight of spleen.
α-Amylase (EC 3.2.1.1) was purified from the muscle and intestine of the parasitic helminth of pigs Ascaris suum. The enzymes from the two sources differed in their properties. Isoelectric focusing revealed one form of α-amylase from muscles with pI of 5.0, and two forms of amylase from intestine with pI of 4.7 and 4.5. SDS/PAGE sug­gested a molecular mass of 83 kDa and 73 kDa for isoenzymes of a-amylases from in­testine and 59 kDa for the muscle enzyme. α-Amylase from intestine showed maxi­mum activity at pH 7.4, and the enzyme from muscle at pH 8.2. The muscle enzyme was more thermostabile than the intestinal α-amylase. Both the muscle and intestine amylase lost half of its activity after 15 min at 70°C and 50°C, respectively. The Km val­ues were: for muscle amylase 0.22 ,ug/ml glycogen and 3.33 ,ug/ml starch, and for in­testine amylase 1.77 ug/ml glycogen and 0.48 ug/ml starch. Both amylases were acti­vated by Ca and inhibited by EDTA, iodoacetic acid, p-chloromercuribenzoate and the inhibitor of α-amylase from wheat. No significant differences were found between the properties of a-amylases from parasites and from their hosts.
Activity of α-amylase in somatic muscles in different parts of the female body of Ascaris suum was examined. Highest activity was indicated for the head (31.38 u/mg) and the tail (22.98 u/mg). No statistically significant differences of enzyme activity were found between 1-1.5 cm segments into which the remaining part of worm’s body wall was divided. Total α-amylase activity in isolated muscles from the body wall situated posteriorly to the nematode’s vulva was higher than in the anterior part (p<0.05). Higher enzyme activity was also noted in dorsal muscles than in ventral.
The provenance of α-amylase from intestines of adult Ascaris suum was investigated by Ouchterlony method using sera of guinea pigs vaccinated with the enzyme protein extracted from the worm intestine or pig pancreas. No cross-reactivity was observed between sera raised against pig α-amylase and A. suum enzyme. The results support suggestions that α-amylase present in A. suum intestine is produced by the nematode and not required from the host intestine.
The studies were conducted during the school year of 1996/1997 among the children at the age of 5, 6 and 7 years old from Olsztyn and nearby municipality of Purda. In total, 151 children were examined by Graham's method. The presence of eggs of the parasite was confirmed in 13.3% of the total examined population. The infestation was tower in Olsztyn (12.0%) and the lowest in Purda (9.4%) but in the former state-owned Farm village Prajłowo it reached 27.8%. In general, the pinworms were found more frequently in 7 year old children (23.33%) than in case of the others (8.69% and 7.14% for 5 and 6 year old children respectively). In the study, younger boys were more frequently infested than the girls.
The guinea pigs were administrated vit. A (400 i.u.), vit. B₂ (1 mg) or vit. B₁₅ (5 mg). On the 9-th day of the experiment part of them was infectpd with 5000 invasive eggs of Ascaris suum. The invasion lasted 6 days and was controlled by lungs and kidney weight, and number of larvae in the lungs. The activity of amylase was determined by saccharogenic method in both organs. In the lungs of infected animals the activity of alpha-amylase was abouth 3 times lower than in the control. The infection of guinea pigs which were given vitamins did not cause change of enzyme's activity. In the kidney directive tendency was the same, but the differences were smaller. The infection resulted in an increase of relative mass of lungs. This index and number of larvae was considerable smaller in guinea pigs with vitamins A and B₁₅ administration. Any testing agent did not cause change of relative weight of kidney.
The studies were carried out on 40 guinea pig males weighting about 230 g. The experimental animals were infected with 7000 invasive eggs of Ascaris suum. On the 3-rd, 7-th and 10-th day after infection the activity of alpha-amylase was estimated according to Caraway's method in serum, liver, pancreas, lungs, kidneys and spleen. The infection of guinea pigs results in increased activity of enzyme in serum and spleen, and decreased in pancreas, liver, kidneys and lungs. On the 3-rd day after infection the changes in amylase activity were the most intense.
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Similar patterns of hydrolases were observed in three species representing two genera of entomopathogenic nematodes: Steinernema affinis, S. feltiae, and Heterorhabditis zealandica. The same enzymes were present in the studied nematodes but they differed in the level of activity of individual sub-classes of enzymes. A higher activity of esterases and proteolytic enzymes could be observed for H. zealandica than for S. affinis and S. feltiae. On the other hand, the activity of glycosidases in steinernematids was generally much higher than in H. Zealandica.
Introduction. The influence of infection with two species of entomopathogenic nematodes of Steinernematidae family on metabolism of glycogen and trehalose of the host was studied. Material and methods. Last instar larvae (L₇) of Galleria mellonella were experimentally infected with Steinernema affinis and S. feltiae. At 6, 12, 18 and 24 h after infection concentrations of trehalose and glycogen as well as activity of trehalase and α-amylase were determined. Results. The content of glycogen was lower in insects infected with S. feltiae than in the controls and animals infected with S. affinis. The content of trehalose was higher in insects from both infected groups than in the controls. Its concentration was slightly higher in larvae infected with S. affinis than in those infected with S. feltiae. The activity of α-amylase after infection with S. affinis was low. It was significantly higher in insects infected with S. feltiae. In animals of both infected groups, following a significant reduction at 6 h, the activity of trehalase remained at a similar level, higher than in the controls. In the paper the effects of infection with (i) different species of entomopathogenic nematodes and (ii) the importance of the developmental stage of the insect-host for changes in its metabolism of glycogen and trehalose were discussed.
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