Hostname: page-component-77f85d65b8-grvzd Total loading time: 0 Render date: 2026-04-20T04:32:08.542Z Has data issue: false hasContentIssue false

Activation of skeletal muscle protein breakdown following consumption of soyabean protein in pigs

Published online by Cambridge University Press:  09 March 2007

B. Löhrke*
Affiliation:
Research Institute for Biology of Farm Animals, Dummerstorf-Rostock, Departments of Animal Nutrition “Oscar Kellner“ and Genetics and Biometry, 18059 Rostock, Justus-von-Liebig-Weg 2, Germany
E. Saggau
Affiliation:
Research Institute for Biology of Farm Animals, Dummerstorf-Rostock, Departments of Animal Nutrition “Oscar Kellner“ and Genetics and Biometry, 18059 Rostock, Justus-von-Liebig-Weg 2, Germany
R. Schadereit
Affiliation:
Research Institute for Biology of Farm Animals, Dummerstorf-Rostock, Departments of Animal Nutrition “Oscar Kellner“ and Genetics and Biometry, 18059 Rostock, Justus-von-Liebig-Weg 2, Germany
M. Beyer
Affiliation:
Research Institute for Biology of Farm Animals, Dummerstorf-Rostock, Departments of Animal Nutrition “Oscar Kellner“ and Genetics and Biometry, 18059 Rostock, Justus-von-Liebig-Weg 2, Germany
O. Bellmann
Affiliation:
Research Institute for Biology of Farm Animals, Dummerstorf-Rostock, Departments of Animal Nutrition “Oscar Kellner“ and Genetics and Biometry, 18059 Rostock, Justus-von-Liebig-Weg 2, Germany
S. Kuhla
Affiliation:
Research Institute for Biology of Farm Animals, Dummerstorf-Rostock, Departments of Animal Nutrition “Oscar Kellner“ and Genetics and Biometry, 18059 Rostock, Justus-von-Liebig-Weg 2, Germany
H. Hagemeister
Affiliation:
Research Institute for Biology of Farm Animals, Dummerstorf-Rostock, Departments of Animal Nutrition “Oscar Kellner“ and Genetics and Biometry, 18059 Rostock, Justus-von-Liebig-Weg 2, Germany
*
*Corresponding author: Dr Berthold Löhrke, fax +49 382 08 686 02, email loehrke@fbn-dummerstorf.de
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the 'Save PDF' action button.

Diets with protein of inferior quality may increase protein breakdown in skeletal muscle but the experimental results are inconsistent. To elucidate the relationship, pigs were fed isoenergetic and isonitrogenous diets based on soyabean-protein isolate or casein for 15 weeks, with four to six animals per group. A higher plasma level of urea (2.5-fold the casein group value, P=0.01), higher urinary N excretion (2.1-fold the casein group value, P=0.01), a postabsorptive rise in the plasma levels of urea, 3-methylhistidine and isoleucine in soyabean protein-fed pigs suggested recruitment of circulatory amino acids by protein breakdown in peripheral tissues. Significant differences between dietary groups were detected in lysosomal and ATP-dependent proteolytic activities in the semimembranosus muscle of food-deprived pigs. A higher concentration of cathepsin B protein was found, corresponding to a rise in the cathepsin B activity, in response to dietary soyabean protein. Muscle ATP-stimulated proteolytical activity was 1.6-fold the casein group value (P=0.03). A transient rise in the level of cortisol (2.9-times the casein group value, P=0.02) occurred in the postprandial phase only in the soyabean group. These data suggest that the inferior quality of dietary soyabean protein induces hormonally-mediated upregulation of muscle protein breakdown for recruitment of circulatory amino acids in a postabsorptive state.

Information

Type
Research Article
Copyright
Copyright © The Nutrition Society 2001