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

• Published in: Plant foods for human nutrition (Dordrecht) 1992-10, Vol.42 (4), p.337-349
• Main Authors: Peace, R.W. (Health and Welfare Canada, Ottawa, Ont. (Canada). Bureau of Nutritional Sciences), Sarwar, G, Botting, H.G, Touchburn, S.P
• Format: Article
• Language: English
• Subjects: Amino Acids - blood; Animal Nutritional Physiological Phenomena; Animals; Biological and medical sciences; CRECIMIENTO; CROISSANCE; DEFICIENCY DISEASES; DIET; DIETA; ENFERMEDADES CARENCIALES; ENZYME INHIBITORS; Ethionine - pharmacology; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Glycine max; GROWTH; HEALTH; INHIBIDORES DE ENZIMAS; INHIBITEUR D'ENZYME; Kidney - anatomy & histology; Liver - anatomy & histology; MALADIE DE CARENCE; Male; METHIONINE; Methionine - blood; METIONINA; Organ Size - drug effects; Pancreas - anatomy & histology; PLANT PROTEINS; PROTEINAS VEGETALES; PROTEINE VEGETALE; RAT; RATA; RATS; Rats, Wistar; REGIME ALIMENTAIRE; SALUD; SANTE; SOJA; SOYBEANS; Sulfur - metabolism; TRIPSINA; TRYPSIN; Trypsin Inhibitors - pharmacology; TRYPSINE; Weight Gain - drug effects
• ISSN: 0921-9668; 1573-9104
• DOI: 10.1007/BF02194095

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 100 g 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 of ad 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.