Schistosoma mansoni: Effect of insulin and a low-molecular-weight fraction of serum on schistosomula in chemically defined media

Francesca Levi-Schaffer*, Moshe Smolarsky

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

31 Scopus citations


Improved chemically defined media for the in vitro maintenance of Schistosoma mansoni schistosomula are described. Artificially transformed schistosomula could be maintained for 7-13 days in a mixture of equal volumes of RPMI 1640 and F-12 supplemented with 30 nM sodium selenite (DSM). Addition of 50 μg/ml insulin increased the survival time to 13-22 days. Insulin at concentrations lower than 25 μg/ml was not effective. Other proteins like hemoglobin, bovine serum albumin, human serum albumin, and lysozyme were also ineffective. A low-molecular-weight fraction from human serum that passes through an Amicon PM 10 filter (10K fraction) increased the survival time to 19-30 days. The schistosomula maintained under these conditions were actively motile for the above periods but did not grow to a significant extent and did not reach the closed-gut stage. However schistosomula maintained for 7 days in DSM or in DSM containing 50 μg/ml insulin and then transferred into DSM-serum (1:1) developed normally after an adaptation period. Insulin greatly increased the initial rate of development and the resistance of mechanically transformed schistosomula to antibodies and complement. Thus, in chemically defined synthetic medium (DSM) in the presence of 50 μg/ml insulin, schistosomula developed a resistance similar to that reached in the presence of 50% serum, but at a somewhat slower rate. On the other hand, in synthetic medium alone without insulin, both the development rate and the extent of resistance were much lower.

Original languageAmerican English
Pages (from-to)378-385
Number of pages8
JournalExperimental Parasitology
Issue number3
StatePublished - Dec 1981
Externally publishedYes

Bibliographical note

Funding Information:
This study was supported in part by a grant from the Rockefeller Foundation. We wish to express our gratitude to Professor Ruth Amon for her help and many fruitful discussions. We are grateful to Mr. M. Ferrara for his excellent technical assistance.


  • Antibody
  • Blood fluke
  • Complement
  • Cultivation, in vitro
  • Fractionation
  • Insulin
  • Rabbit
  • Resistance
  • Schistosoma mansoni
  • Schistosomula
  • Serum
  • Trematode


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