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Biomedical subjects

S Ghatak

Publications and source records attributed to S Ghatak.

At least 73 records · Page 4Linked to original sources

Monoamine oxidase in adult Ascaridia galli.

Monoamine oxidase (MAO), catalysing oxidative deamination of biogenic monoamines, has been detected in adult Ascaridia galli. MAO was present in mitochondria and deaminated noradrenaline at the maximal rate, although serotonin, adrenaline, tyramine and dopamine were also degraded but more slowly. Of the organs studied, the body wall, female reproductive organ and intestine, the body wall (containing neuronal structures) showed highest MAO activity. Km value for chick ascarid mitochondrial MAO using tyramine as substrate was 1.66 X 10(-3) M and it was most active at 2.5 mM tyramine concentration, pH 7.5 and 40 degrees C. MAO of A. galli appeared to be thermolabile as nearly 80% of its activity was lost when the incubation temperature was increased 5 degrees above optimum.

Animals↗

Lysosomal enzymes in the spleen of albino rats, mice and Mastomys natalensis during Plasmodium berghei infection.

Activities of certain acid hydrolases of the spleen were followed in three different rodents during the course of Plasmodium berghei infection. In albino rats where sterile immunity against the infection develops, the specific activities of a few acid hydrolases first declined then increased from day 7 and showed a several-fold increase over control values when there were no detectable parasites in peripheral circulation. In contrast, in Mastomys natalensis and albino mice which succumb to infection the levels of these enzymes were reduced throughout the course of infection. These results indicate a close correlation between host resistance to infection and the level of lysosomal enzymes in spleen.

Animals↗

Lysosomal enzyme in Mastomys natalensis during Dipetalonema viteae infection.

Activities of certain acid hydrolases (viz. acid phosphatase, beta-glucosidase, beta-galactosidase, N-acetyl-beta-D-glucosaminidase and cathepsine) of post mitochondrial fraction of liver and spleen were studied during the course of Dipetalonema viteae infection in Mastomys natalensis. The values are significantly higher from prepatent to patent phase of infection as compared with normal animals. However, a decrease in the activity of hepatic acid phosphatase and N-acetyl-beta-D-glucosaminidase was noticed in latent phase of infection while a several fold increase in the activity of these enzymes was observed in splenic tissue when there were no detectable microfilariae (mf) in peripheral circulation. The results suggest that lysosomal acid hydrolases which constitute an important component of resistance may be activated by mf products through the sensitized cells of RE system.

Acetylglucosaminidase↗

Setaria cervi: enzymes in microfilariae and in vitro action of antifilarials.

Microfilariae of bovine filarial parasite Setaria cervi are equipped with the enzymes of glycolysis, pentose phosphate and PEP-succinate pathways and thus resemble the adult form in its metabolic pattern. Malate dehydrogenase was the most active enzyme in microfilariae followed by lactic dehydrogenase and fumarase, while phosphoglucoisomerase, PEP-carboxykinase and FDP-aldolase were comparatively less active. The very low ratio of PK/PEPCK in S. cervi microfilariae indicates active fixation of CO2 into PEP to produce oxalacetate. Centperazine and diethylcarbamazine significantly inhibited PEP-carboxykinase, fumarate reductase and succinic dehydrogenase, suggesting that these antifilarials probably exert microfilaricidal action by blocking the PEP-succinate pathway.

Animals↗

Biochemical composition of microfiliarial and adult stages of Setaria cervi.

The microfilariae and adults of Setaria cervi, a filarial parasite of Indian water-buffalo (Bubalus bubalis Linn.) and of other ruminants were analysed for various biochemical constituents. Both stages of the parasite were rich in protein, carbohydrate, and lipids while nucleic acids were detectable in only small amounts. Microfilariae and adults contained 10 and 25% dry matter, 57.4 and 63.0% protein, 8.9 and 14.8% carbohydrate, and 12.8 and 9.2% lipid, respectively. Reducing sugars accounted for 52 and 67% respectively of the total carbohydrate in these two stages. Glycogen accounted for 95% of total carbohydrate in the cold PCA soluble fraction of adult worms while its concentration in microfilariae was very low. Glucose was the main constituent of reducing sugars while concentrations of fructose were very low. Microfilariae contained more lipids, nucleic acids, mucopolysaccharides, and total phosphorus than adults. The phospholipid percentage was higher in microfilariae than in adults. The amino acid pattern of both stages was very similar.

Amino Acids↗

Glycogen pattern in natural and alternate hosts infected with Litomosoides carinii.

Litomosoides carinii infection causes a decrease in liver glycogen levels in the albino rat, an alternate host, but not in its natural host, the cotton-rat. In the albino rat the primary infection is rejected by about 120 days after infection whereas in the cotton-rat rejection does not occur. Consequently, the drop in hepatic glycogen levels in the albino rat has some correlation with the immune status of the host.

Animals↗

Setaria cervi: enzymes of glycolysis and PEP-succinate pathway.

Setaria cervi, the filarial parasite inhabiting the Indian water buffalo (Bubalus bubalis Linn.) contained almost all the enzymes involved in glycogen degradation. Significant activities of glycogen phosphorylase, glucokinase, phosphoglucomutase, phosphoglucose isomerase, phosphofructokinase, FDP-aldolase, glyceraldehyde-3-phosphate dehydrogenase, phosphopyruvate hydratase, pyruvate kinase, lactate dehydrogenase glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were detected in cell-free extracts of whole worms. The presence of PEP-carboxykinase, malate dehydrogenase, fumarase and fumarate reductase revealed the functioning of the PEP-succinate pathway in addition to phosphorylating glycolysis and pentose phosphate pathway in the parasite. Excepting fumarate reductase all other enzymes were localized in the particulate-free cytosol fraction, although small amounts of glycogen phosphorylase, aldolase and lactate dehydrogenase were also detected in the mitochondrial fraction.

Animals↗