Ather H. Siddiqi

Comparative studies on the lipid composition of some digenetic trematodes

Abstract Yusufi A. N. K. & Siddiqi A. H. 1976. Comparative studies on the lipid composition of some digenetic trematodes. International Journal for Parasitology6: 5–8. Neutral lipids and phospholipids of six digenetic trematodes, Cotylophoron cotylophorum, Gastrothylax crumenifer and Gigantocotyle explanatum from water buffalo, Echinostoma malayanum and Fasciolopsis buski from pig and Isoparorchis hypselobagri from cat-fish were analyzed. Total lipid concentrations in trematodes varied considerably irrespective of their hosts and habitats. While triglycerides were the major components in all species, considerable amounts of phospholipids and free fatty acids were present in all species. Cholesterol was minimum (4–9%) in more or less all species, except in F. buski, where cholesterol, phospholipids and triglycerides constituted 13–14% and free fatty acids around 7%. Among phospholipids, choline and ethanolamine phosphatides were major polar lipids. Sphingomyelin and cardiolipin were present as small fractions and lysophosphatidylcholine was evenly distributed among all the species (9–12%) except in F. buski, which contained a little higher content (15%).

Spectrophotometric analysis of haemoglobins of some digenetic trematodes and their hosts

The haemoglobins of six different species of trematodes: Gastrothylax crumenifer, Srivastavaia indica, Gigantocotyle explanatum, Fasciolopsis buski, Gastrodiscoides hominis, Isoparorchis hypselobagri and their three different hosts: Bubalus bubalis, Sus scrofa, and Wallago attu were spectrophotometrically investigated, and were found to contain porphyrin IX as the common prosthetic group. Oxyhaemoglobin, carbonmonoxy-haemoglobin and reduced haemoglobin of all 6 species of trematodes and their 3 hosts under study gave similar absorption maxima. Distinct differences were, however, observed in the nature of the spectral curves of cyanmethaemoglobin which exhibit 2 absorption maxima in the beta and the alpha region in the case of all trematodes whereas in the case of similar host haemoglobin derivatives only one single broad peak in the 536-540 nm region was obtained. With respect to pyridine derivatives all the trematode haemoglobins show a sharp peak in the alpha region and a minor hump in the beta region except Gastrothylax crumenifer. All three host pyridine haemoglobin derivatives show only a single broad peak at 570 nm.

Nonprotein nitrogenous composition of the protonephridial fluid of the trematode Fasciola gigantica

Abstract 1. 1. A simple technique is described for obtaining terminal proto-nephridial fluid in Fasciola gigantica . 2. 2. An analysis detected seven unequally distributed ninhydrin positive substances of which six were identified as proline, alanine, histidine, phenyla-lanine, serine and lysine. Proline, alanine and histidine were by far the most common. 3. 3. Ammonia and urea were found in all samples analysed. 4. 4. Comparison of the amino acid distribution in the protonephridial fluid with that reported for the body tissue and bathing media of F. hepatica suggested possible functions for the protonephridial system in the liver fluke.

Comparison of the hemoglobins of the platyhelminths Gastrothylax crumenifer and Paramphistomum epiclitum (Trematoda: Paramphistomatidae)

1. Gastrothylax crumenifer and Paramphistomum epiclitum parasitize the water buffalo Bubalus bubalis. 2. Gastrothylas hemoglobin consisted of two fractions of ca 30,000 and ca 18,000 by gel filtration. SDS-electrophoresis showed both to be single, ca 15,000 chains. 3. Paramphistomum hemoglobin was ca 16,000 by both gel filtration and SDS-electrophoresis. 4. Reversed-phase chromatography of carboxymethylated trematode and buffalo globins gave single peaks and two peaks, respectively. Although Paramphistomum hemoglobin provided and N-terminal sequence, Gastrothylax hemoglobin did not, suggesting blocked N-terminals. The buffalo sequences were found to be identical to the sequences of the alpha and beta chains of bovine hemoglobin. 5. Although Paramphistomum hemoglobin consists of only one chain, Gastrothylax hemoglobin consists either of one chain which aggregates to a dimer or of two different chains, only one of which aggregates to a dimer.

Purification and properties of the hemoglobins of the platyhelminth Isoparorchis hypselobagri (trematoda: Isoparorchidae) and its host Wallagu attu (catfish)

1. The hemoglobins of the trematode Isoparorchis hypselobagri and of its host Wallagu attu (catfish) were isolated and purified. 2. SDS-polyacrylamide gel electrophoresis showed both to consist of single, 15-17 kDa chains, having different electrophoretic mobilities. 3. Isoelectric focusing showed the trematode hemoglobin to be homogeneous with a pI of 4.2 and the host hemoglobin to consist of several components. 4. Gel filtration of freshly prepared trematode hemoglobin revealed one peak corresponding to M(r) approximately 17 kDa; gel filtration of a preparation which had been stored for 2-3 months demonstrated the presence of two peaks, whose elution volumes corresponded to M(r) of ca 35 and 17 kDa, respectively. 5. Reversed-phase chromatography of carboxymethylated 35 and 17 kDa peaks on a C8 column, gave a single peak a and two peaks b and c, respectively. 6. Edman degradation of peaks a, b and c obtained provided identical sequences of 27 amino acid residues for peaks a and c and another sequence differing at 10 of the 27 positions, for peak b. Edman degradation of the freshly prepared Isoparorchis hemoglobin provided the first 15 amino acid residues found for peaks a and c. The host hemoglobin gave an N-terminal sequence completely different from the trematode sequences. 7. Since gel filtration of the 35 and 17 kDa peaks showed no sign of an interconversion equilibrium, it appears that the 35 kDa peak and peak a represent a disulfide-bonded dimer of a monomer globin chain which shares the 27 N-terminal residues with chain c, the major monomer globin component of the 17 kDa peak.(ABSTRACT TRUNCATED AT 250 WORDS)

Some aspects of carbohydrate metabolism of digenetic trematodes from Indian water buffalo and catfish

SummaryVarious enzymatic systems of glycolysis and tricarboxylic acid cycle were studied in the cell-free extracts of three digenetic trematodes —Gastrothylax crumenifer andSrivastavaia indica from the rumen of the water buffaloBubalus bubalis L., andIsoparorchis hypselobagri from the catfishWallago attu. The significant activities of glucose-6-phosphate dehydrogenase, glucose-6-phosphatase and fructose-1,6-diphosphatase suggested the possible existence of the pentosephosphate pathway and a capacity for gluconeogenesis in all trematodes. However, marked quantitative differences in enzyme activities were found in these parasites.

Gas content of swim bladder of Wallago attu and oxygen consumption in Isoparorchis hypselobagri (Trematoda)

SummaryThe swim bladder gas of Wallago attu contains O2 (22–58 mm Hg) and the presence or absence of Isoparorchis hypselobagri does not influence the O2 content of the swim bladder. Glucose increases the O2 consumption of I. hypselobagri by 50%. With the passage of in vitro culture time, the rate of O2 consumption gradually decreases to the extent of 64% on the 40th day. The optimal temperature for O2 consumption is 30° C beyond which the rise in temperature is detrimental to the fish trematode as manifested by the decrease in their O2 consumption.

Non-specific alkaline phosphomonoesterases of eight species of digenetic trematodes

Alkaline phosphatases from different trematodes occupying the same habitat have identical pH otima but different levels of enzyme activities. Isoparorchis hypselobagri, from the fish Wallago attu, shows four to six times more enzyme activity than Fasciolopsis buski, Gastrodiscoides hominis and Echinostoma malayanum, from the pig Sus scrofa, and Fasciola gigantica, Gigantocotyle explanatum, Cotylophoron cotylophorum and Gastrothylax crumenifer, from the buffalo Bubalus bubalis. At least two peaks of activity at different levels of pH were obtained for each trematode examined. Both Gastrodiscoides hominis and Isoparorchis hypselobagri enzymes had three peaks of alkaline phosphatase activity. The optimum temperature for maximum enzyme activity was 40 degrees C, above which rapid inactivation occurred. At temperatures below 40 degrees C, the enzymes of fish and mammalian trematodes did not behave similarly; I. hypselobagri enzyme being active over a wider range of temperature (20 degrees-40 degrees C. Various concentrations of KCN and arsenate proportionately inhibited enzyme activity. NaF Did not significantly influence enzyme activity, while Mg++ and Co++ acted as activators. The extent of inhibition or activation of enzyme activity of different trematodes varied, probably due to species differences. Both inhibition and activation of I. hypselobagri enzyme was higher than in the case of other trematodes.

Characterization of sterols of three digenetic trematodes of buffalo

Sterols of three digenetic trematodes were isolated and characterized by infrared and 1H nuclear magnetic resonance spectroscopies, and gas-liquid chromatography and gas chromatography-mass spectrometry. Sterols identified were cholesterol, cholestanol, 24-methylcholesterol, 24-methylcholestanol, 24-ethyl-22-dehydrocholesterol, 24-ethyl-22-dehydrocholestanol, 24-ethylcholesterol and 24-ethylcholestanol.

Quantitative studies on acetylcholinesterase in seven species of digenetic trematodes.

SummaryQuantitative estimation of absolute levels and in vitro release of acetylcholinesterase (AChE) in seven species of digenetic trematodes: Isoparorchis hypselobagri from the swim bladder of catfish, Wallago attu; Srivastavaia indica and Gastrothylax crumenifer from the rumen, and Gigantocotyle explanatum from the liver of the water buffalo, Bubalus bubalis; Fasciolopsis buski, Echinostoma malayanum from the small intestine and Gastrodiscoides hominis from the caecum of the pig, Sus scrofa revealed that the enzyme is present in remarkably high quantities in species which inhabit gastrointestinal tract compared with those that parasitize liver and swim bladder. The rate of in vitro release of AChE also varies with the species which supports the view that such differential secretion probably takes place in situ as well to counteract peristalsis and it is a biochemical adaptation on the part of these trematodes.