2 results
The uptake of radioactive phosphorus from host tissues and fluids by nematode parasites
- W. P. Rogers, Marian Lazarus
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- Journal:
- Parasitology / Volume 39 / Issue 3-4 / February 1949
- Published online by Cambridge University Press:
- 06 April 2009, pp. 245-250
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- Article
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1. Compared with the mammalian intestine, uterus and blood serum, the corresponding organs and perienteric fluid of Ascaris lumbricoides were found to have a high phosphorus content. The muscle of the parasite, however, contained little more than half the phosphorus found in the mammalian muscle.
2. A. lumbricoides took up inorganic ortho-phosphate largely or exclusively through the alimentary tract. Small amounts were taken up by the cuticle and the lateral line system, but did not appear to pass on to other tissues.
3. Nippostrongylus muris in the intestine of the rat took up radioactive phosphorus which had been injected into the host intramuscularly. When the host was dosed per os the radioactivity appeared in the parasites at a lower concentration than in the host's small intestine.
4. Ascaridia galli failed to show any radio-activity when host birds were injected intravenously with inorganic orthophosphate containing P32. A sudden rise and fall in the radioactivity of the parasites were found when host birds were dosed per os.
5. It is suggested that nematode parasites have a high demand for phosphate which they take up largely per os. Ascaridia galli feeds rapidly, but with poor phosphate absorption, on host gut contents. Nippostrongylus muris feeds on host tissues. It is suggested that the different feeding habits of N. muris and Ascaridia galli may have some relation to the efficacy of anthelmintics against these parasites.
The authors are indebted to Dr M. Kamen and Dr E. Reinhard of Washington University, St Louis, for a gift of radioactive phosphorus. Thanks are also due to Mr E. Parrish and Mr L. Turk of the McMaster Laboratory for their capable assistance.
Glycolysis and related phosphorus metabolism in parasitic nematodes
- W. P. Rogers, Marian Lazarus
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- Journal:
- Parasitology / Volume 39 / Issue 3-4 / February 1949
- Published online by Cambridge University Press:
- 06 April 2009, pp. 302-314
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1. The r.q. of whole Neoaplectana glaseri rose from 0·56 to 1·10 when glucose was added to the medium. The Qo2 was only slightly affected. Respiration of other nematode parasites was largely unaffected by exogenous glucose. Pyruvate had little or no effect.
2. Inorganic phosphate increased when Ascaris lumbricoides muscle brei was incubated. In the presence of fluoride, or when aqueous extracts were used, easily and difficultly hydrolysable phosphate was formed. Phosphatase activity was dominant even in aqueous extracts of A. lumbricoides intestinal tissues and fluoride inhibited Po formation only slightly. Ptot., and PresIdual fell markedly in whole A. lumbricoides which had been incubated anaerobically. Under aerobic conditions Po fell slightly, but the other components rose considerably. Phosphorylative activity of A. lumbricoides ovary was greater than in the muscle. Phosphorus compounds in perienteric fluid did not change during incubation.
3. The breakdown of glycogen and the formation of glucose in aqueous extracts of Ascaridia galli was inhibited by fluoride and phloridzin. Polysaccharide was synthesized in fluoride-poisoned preparations when glucose 1-phosphate was added. Polysaccharide formation in Ascaris lumbricoides fluoridepoisoned muscle preparations was demonstrated without the addition of Cori ester.
4. Fructose 1:6-diphosphate added to aqueous extracts of Ascaridia galli and Nematodirus spp. was rapidly metabolized at pH 6·5. At pH 7·2 the fructose content increased.
5. In aqueous extracts of Nematodirus or Ascaridia brei which had been autolysed for short periods, 55–60% of the glycogen utilized appeared as glucose. Only small amounts of lactate were formed. Aqueous extracts of Nematodirus and Ascaridia brei which had been autolysed for long periods formed glucose in excess of the glycogen disappearing. When perienteric fluid, which contained amylase, was removed from A. galli before autolysis, the amount of glucose formed was very much reduced. It is suggested that the excess glucose was formed from dextrins which were not estimated as glycogen and which were hydrolysed by perienteric fluid amylase during incubation.
Lactate decreased during the incubation of extracts prepared from brei which had been autolysed for long periods.
6. Bicarbonate decreased during the anaerobic incubation of aqueous extracts of Nematodirus spp. and Ascaridia galli which were buffered with CO2-bicarbonate. The decrease in bicarbonate was in excess of the CO2 expelled from the medium by acid formation.
7. The acid-soluble phosphorus compounds of the different tissues of Ascaris lumbricoides were examined. Compounds similar to a.t.p. were found in the intestine, ovary, muscle and possibly also in the perienteric fluid. The acid-unstable phosphorus compounds did not appear to be either creatine- or arginine-phosphate. Compounds similar to Embden ester were found in the ovary and muscle. The occurrence of the phosphate compounds found in the parasite is compared with figures given for other organisms.
8. It is concluded that carbohydrate fermentation as far as lactate in nematode parasites was similar to that found in yeast and mammalian muscle. Energy was transferred by means of high-energy phosphate bonds.
9. Phospholipids, which were found in considerable amounts in the tissues of A. lumbricoides, were estimated as lecithin, sphingomyelin and serine- and ethanolamine-containing phospholipids. The amounts of the phospholipids found in the parasite tissues are compared with figures given for other organisms.
The authors are deeply indebted to Prof. D. Keilin and Dr T. Mann of the Molteno Institute, Cambridge, for their advice and critical reading of the manuscript. Thanks are also due to Dr E. F. Gale and Dr E. Friedemann for advice on analytical procedures.