Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-05T04:07:14.814Z Has data issue: false hasContentIssue false

The role of carbon dioxide in the metabolism of adult Haemonchus contortus, in vitro

Published online by Cambridge University Press:  06 April 2009

P. F. V. Ward
Affiliation:
Biochemistry Department, A.R.G. Institute of Animal Physiology, Babraham, Cambridge, CB2 4AT
N. S. Huskisson
Affiliation:
Biochemistry Department, A.R.G. Institute of Animal Physiology, Babraham, Cambridge, CB2 4AT

Summary

Adult Haemonchus contortus worms simultaneously excrete and fix CO2. Their initial content of CO2 was measured as 4·55 μmoles/100mg wet weight and their excretion rate in air as 1 μmole/100 mg wet weight/h for at least 4 h. When the worms were incubated either aerobically or anaerobically with 14CO2 most of the metabolized radioactivity was associated with propan-1-ol and propionate but small amounts were found in succinate and lactate. No radioactivity was associated with ethanol or acetate, two major catabolites of glucose. Stepwise degradation of the metabolized radioactive propanol and propionate showed that all the radioactivity in both compounds was associated with carbon atom no. 1. These results show that H. contortus has much in common with the anaerobic energy metabolism of Ascaris lumbricoides but they are not inconsistent with the utilization of the tricarboxylic acid cycle by the worm. H. contortus worms were found to metabolize their excretory products. When they were incubated with either [2,3-14C]succinate or [2-14C]acetate, 14CO2 was excreted under aerobic but not under anaerobic conditions. These results are consistent with a pathway similar to that used by Ascaris operating alone under anaerobic conditions and together with the tricarboxylic acid cycle under aerobic conditions.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1980

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Allen, S. H. G., Kellermeyer, R. W., Stjernholm, R. L. & Wood, H. G. (1964). Purification and properties of enzymes involved in the propionie acid fermentation. Journal of Bacteriology 87, 171–87.CrossRefGoogle ScholarPubMed
Bueding, E., Kmetec, E., Swartzwelder, C., Abadie, S. & Saz, H. J. (1961). Biochemical effects of dithiazanine on the canine whipworm Trichuris vulpis. Biochemical Pharmacology 5, 311–22.CrossRefGoogle Scholar
Coadwell, W. J. & Ward, P. F. V. (1977). Annual variation in the growth of Haemonchus contortus in experimental infections of sheep and its relation to arrested development. Parositology 74, 121–32.CrossRefGoogle Scholar
Evans, E. A. (1976). Self decomposition of radiochemicals: principles, control, observations and effects. Review 16, pp. 71–4. The Radiochemical Centre, Amersham, England.Google Scholar
Fairbairn, D. (1954). The metabolism of Heterakis gallinae. II. Carbon dioxide fixation. Experimental Parasitology 3, 5263.CrossRefGoogle Scholar
Huskisson, N. S. & Ward, P. F. V. (1978). A reliable method for scintillation counting of 14CO2 trapped in solutions of sodium hydroxide, using a scintillant suitable for general use. International Journal of Applied Radiation and Isotopes 29, 729–34.CrossRefGoogle Scholar
Peters, J. P. & Van Slyke, D. D. (1932). Quantitative Clinical Chemistry, vol. 2. pp. 269–74, 290–2. Baltimore: Williams and Wilkins.Google Scholar
Pritchard, R. K. & Schofield, P. J. (1968). The metabolism of phosphoenolpyruvate and pyruvate in the adult liver fluke Fasciola hepatica. Biochimica et biophysica acta 170, 6376.CrossRefGoogle Scholar
Saz, H. J. & Lescure, O. L. (1969). The function of phosphoenolpyruvate carboxykinase and malic enzyme in the anaerobic formation of succinate by Ascaris lumbricoides. Comparative Biochemistry and Physiology 30, 4960.CrossRefGoogle ScholarPubMed
Van Vugt, F., Van Der Meer, P. & Van Den Bergh, S. G. (1979). The formation of propionate and acetate as terminal processes in the energy metabolism of the adult live fluke Fasciola hepatica. International Journal of Biochemistry 10, 1118.CrossRefGoogle Scholar
Ward, P. F. V. (1974). The metabolism of glucose by Haemonchus contortus in vitro. Parasitology 69, 175–90.CrossRefGoogle Scholar
Ward, P. F. V. & Huskisson, N. S. (1978). The energy metabolism of adult Haemonchua contortus in vitro. Parasitology 77, 255–71.CrossRefGoogle ScholarPubMed
Watts, S. & Fairbairn, D. (1974). Anaerobic excretion of fermentation acids by Hymenolepis diminuta during development in the definitive host. Journal of Parasitology 60, 621–5.CrossRefGoogle ScholarPubMed