Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-28T13:43:52.679Z Has data issue: false hasContentIssue false

Schistosoma mansoni: temporal distribution of radioselenium-labelled schistosomula in lungs of mice during the first two weeks of infection

Published online by Cambridge University Press:  06 April 2009

Jay R. Georgi
Affiliation:
New York State College of Veterinary Medicine, Cornell University, Ithaca, New York 14853
D. A. Dean
Affiliation:
United States Naval Research Institute, Bethesda, Maryland 20014
Beverly L. Mangold
Affiliation:
United States Naval Research Institute, Bethesda, Maryland 20014

Summary

The number of schistosomula in lungs was determined by compressed organ autoradiography at intervals up to 14 days after exposure of mice to 75Se-labelled cercariae by tail immersion. Probit analysis of compressed lung autoradiogram focus counts, expressed as percentages of initial infection level, yielded estimates of the average time of arrival, peak accumulation in the lungs and average time of departure of schistosomula: 4·5±0·87, 6·3 ± 0·45 and 11±0·58 days, respectively. At peak accumulation 92±3·5 % of the initial number of schistosomula were found in the lungs. It thus appears that little or no significant attrition of schistosomula occurred in the skin and, instead, that most of the 50–70% of penetrant cercariae that fail to reach adulthood are lost somewhere between the pulmonary and hepatic phases of development. Loss of 75Se label from schistosomula during the first 14 days was exponential, with an average half-life of 4·5±0·81 days. However, the high sensitivity of autoradiography tended to compensate for this rather rapid rate of label loss. It was pointed out that autoradiographic detection of schistosomula as discrete loci of radioactivity can also be expected to overcome the problem posed by the accumulation in such tissues as liver and kidney of 75Se label that has become separated from larvae.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1983

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

Clegg, J. A. & Smithers, S. R. (1968). Death of schistosome cercariae during penetration of the skin. II. Penetration of mammalia skin by Schistosoma mansoni. Parasitology 58, 111–28.Google Scholar
Colley, D. G., Magalhães-Filho, A. & Barros-Coelho, R. (1972). Immunopathology of dermal reactions induced by Schistosoma mansoni cercariae and cercarial extract. American Journal of Tropical Medicine and Hygiene 21, 558–68.Google Scholar
Georgi, J. R. (1982). Schistosoma mansoni: quantification of skin penetration and early migration by differential external radioasssay and autoradiography. Parasitology 84, 263–81.Google Scholar
Georgi, J. R., Dean, D. A. & Chandiwanna, S. K. (1982). Quantification of Schistosoma mansoni in mouse lungs by radioassay and autoradiography of 75Se labeled schistosomula. Journal of Parasitology (in the Press).Google Scholar
Lichtenberg, F. von, Sher, A., Gibbons, N. & Doughty, B. L. (1976). Eosinophil-enriched inflammatory response to schistosomula in the skin of mice immune to Schistosoma mansoni. American Journal of Pathology 84, 479500.Google Scholar
Miller, K. L. & Smithers, S. R. (1980). Schistosoma mansoni: the attrition of a challenge infection in mice immunized with highly irradiated live cercariae. Experimental Parasitology 50, 212–21.CrossRefGoogle ScholarPubMed
Miller, P. & Wilson, R. A. (1978). Migration of the schistosomula of Schistosoma mansoni from skin to lungs. Parasitology 77, 281302.CrossRefGoogle ScholarPubMed
Smithers, S. R. & Gammage, K. (1980). The recovery of Schistosoma mansoni from the skin, lungs and hepatic portal system of naive mice and mice previously exposed to S. mansoni: evidence for two phases of parasite attrition in immune mice. Parasitology 80, 289300.Google Scholar
Stirewalt, M. A. (1959). Chronological analysis, pattern and rate of migration of cercariae of Schistosoma mansoni in body, ear and tail skin of mice. Annals of Tropical Medicine and Parasitology 53, 400–13.CrossRefGoogle ScholarPubMed
Wilson, R. A. & Lawson, J. R. (1980). An examination of the skin phase of schistosome migration using a hamster cheek pouch preparation. Parasitology 80, 257–66.Google Scholar