Plant Foods for Human Nutrition

, Volume 42, Issue 4, pp 337–349 | Cite as

Influence of dietary soybean trypsin inhibitors and DL-ethionine on sulfur amino acid adequacy of diets for young rats

  • R. W. Peace
  • G. Sarwar
  • H. G. Botting
  • S. P. Touchburn


Weanling male Wistar rats were fed 20% protein diets based on casein or either of two combinations of soy protein isolate and ground raw soy providing three levels of soybean trypsin inhibitors (SBTI; 0,448 and 808 mg of trypsin inhibited per 100g of diet respectively). DL-ethionine was included at three levels (0,0.05% and 0.10%) with each level of SBTI. After 4, 8 and 12 weeks ofad libitum feeding, diets containing SBTI without DL-ethionine were associated with decreases in weight gain, feed efficiency, serum cholesterol and serum urea nitrogen. Higher levels of triglycerides, glutamate pyruvate transaminase (SGPT) and altered serum free amino acid levels were also found. Increased dietary levels of DL-ethionine also resulted in deficits in growth and feed efficiency, decreased serum cholesterol, increased SGPT and similar alterations in serum free amino acids. Combination of dietary SBTI with DL-ethionine resulted in even greater growth deficits and serum cholesterol decreases as well as increases in SGPT and serum triglycerides and changes in serum free amino acid levels. Methionine deficiency in the young rats fed SBTI and DL-ethionine was indicated by the changes in serum amino acids and growth deficits. Moderation of some effects over the 12 week test period suggested decreased methionine requirements in the older rats.

Key words

Trypsin inhibitors ethionine Wistar rats growth sulfur amino acids 


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Copyright information

© Kluwer Academic Publishers 1992

Authors and Affiliations

  • R. W. Peace
    • 1
    • 2
  • G. Sarwar
    • 1
  • H. G. Botting
    • 1
  • S. P. Touchburn
    • 2
  1. 1.Bureau of Nutritional Sciences, Health Protection BranchHealth and Welfare Canada, Tunney's PastureOttawaCanada
  2. 2.Department of Animal Science and McGill Nutrition and Food Science Centre, Macdonald CollegeMcGill UniversityQuebecCanada

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