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A study of carbohydrate metabolism in the eggs (oncospheres) of the tapeworm, Hymenolepis diminuta, with special reference to glucose

Published online by Cambridge University Press:  06 April 2009

P. W. Pappas  and
G. M. Durka
P. W. Pappas
Affiliation:
Department of Zoology, The Ohio State University, 1735 Neil Avenue, Columbus, OH 43210–1293, USA
G. M. Durka
Affiliation:
Department of Zoology, The Ohio State University, 1735 Neil Avenue, Columbus, OH 43210–1293, USA
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Summary

When incubated in vitro for 24 h, intact eggs, chemically shelled eggs (obtained by treating intact eggs with NaOCl), activated larvae (eggs in which the outer shell and inner envelope were removed), and oncospheres (activated larvae treated with papain to remove the embryophore) absorb and metabolize radioactive glucose. Intact eggs, which are covered by the impermeable shell, absorb only small amounts of exogenous radioactive glucose, while chemically shelled eggs, activated larvae, and oncospheres absorb much larger amounts. Only very small amounts of the exogenous glucose are incorporated into the ethanol-precipitable carbohydrate fraction (which would include glycogen) by any of the preparations of eggs/larvae. However, the glucose is incorporated into higher molecular weight end-products that are liberated into the incubation medium. There is a temporal shift in the ability of activated larvae and oncospheres to metabolize exogenous glucose. Activated larvae and oncospheres absorb but do not metabolize glucose during the first 8 h post-activation. Between 8 and 16 h post-activation, however, virtually all of the absorbed glucose is metabolized into higher molecular weight end-products that are liberated into the incubation media. This temporal shift suggests that activation of oncospheres and cysticercoid morphogenesis are accompanied by distinct changes in carbohydrate metabolism.

Keywords

Hymenolepis diminutaoncospherecarbohydrate metabolismglucose metabolism.
Type
Research Article
Information
Parasitology , Volume 106 , Issue 2 , February 1993 , pp. 201 - 209
Copyright
Copyright © Cambridge University Press 1993

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References

REFERENCES

Anderson, R. M. & Lethbridge, R. C. (1975). An experimental study of the survival characteristics, activity and energy reserves of the hexacanths of Hymenolepis diminuta. Parasitology 71, 137–51.CrossRefGoogle ScholarPubMed
Holmes, S. D. & Fairweather, I. (1985). Hymenolepis diminuta: the mechanism of egg hatching. Parasitology 85, 237–50.CrossRefGoogle Scholar
Lethbridge, R. C. (1971 a). The hatching of Hymenolepis diminuta eggs and penetration of the hexacanths in Tenebrio molitor beetles. Parasitology 62, 445–56.CrossRefGoogle ScholarPubMed
Lethbridge, R. C. (1971 b). The chemical composition and some properties of the egg layers in Hymenolepis diminuta eggs. Parasitology 63, 275–88.CrossRefGoogle ScholarPubMed
Lloyd, J. B. & Whelan, W. J. (1969). An improved method for enzymic determination of glucose in the presence of maltose. Analytical Biochemistry 30, 467–70.CrossRefGoogle ScholarPubMed
Moczoń, T. (1977 a). Histochemical studies on the enzymes of Hymenolepis diminuta (Rud., 1819) (Cestoda). VI. Some enzymes of the synthesis and phosphorolytic degradation of glycogen in oncospheres and cysticercoids. Acta Parasitologica Polonica 24, 275–82.Google Scholar
Moczoń, T. (1977 b). Glycogen distribution and accumulation of radioactive compounds in oncospheres and cysticercoids of Hymenolepis diminuta (Cestoda) after incubation in glucose-14C1–6. Acta Parasitologica Polonica 24, 269–74.Google Scholar
Moczoń, T. (1978). Oxygen consumption by oncospheres of Hymenolepis diminuta (Cestoda). Acta Parasitologica Polonica 26, 19–23.Google Scholar
Pappas, P. W. & Durka, G. M. (1991). Purification, quantification and mechanical hatching of eggs of the tapeworm, Hymenolepis diminuta. International Journal for Parasitology 21, 727–9.CrossRefGoogle ScholarPubMed
Pappas, P. W. & Leiby, D. A. (1986). Variation in the sizes of eggs and oncospheres and the numbers and distributions of testes in the tapeworm, Hymenolepis diminuta. Journal of Parasitology 72, 383–91.CrossRefGoogle ScholarPubMed
Pence, D. B. (1970). Electron microscope and histochemical studies on the eggs of Hymenolepis diminuta. Journal of Parasitology 56, 84–97.CrossRefGoogle ScholarPubMed
Roe, J. H. (1955). The determination of sugar in blood and spinal fluid with the anthrone reagent. Journal of Biological Chemistry 212, 335–43.CrossRefGoogle ScholarPubMed
Smyth, J. D. & McManus, D. P. (1989). The Physiology and Biochemistry of Cestodes. Cambridge: Cambridge University Press.CrossRefGoogle Scholar