TY - JOUR
T1 - Immune system stimulation reduces the efficiency of whole-body protein deposition and alters muscle fiber characteristics in growing pigs
AU - McGilvray, Whitney D.
AU - Johnson, Bradley
AU - Wooten, Hailey
AU - Rakhshandeh, Amanda R.
AU - Rakhshandeh, Anoosh
N1 - Publisher Copyright:
© 2019 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2019
Y1 - 2019
N2 - The effects of immune system stimulation (ISS), induced by repeated injection of Escherichia coli lipopolysaccharide, on the whole-body protein synthesis versus degradation rates, the efficiency of protein deposition (PD), and muscle fiber characteristics in pigs were evaluated. Twelve growing gilts were assigned to two levels of amino acid intake that was predicted based on the potential of each group’s health status for PD and feed intake. Isotope tracer, nitrogen balance, and immunohistochemical staining techniques were used to determine protein turnover, PD, and muscle fiber characteristics, respectively. Protein synthesis, degradation, and PD were lower in immune-challenged pigs than in control pigs (p < 0.05). Strong tendencies for a higher protein synthesis-to-PD ratio (p = 0.055) and a lower protein synthesis-to-degradation ratio (p = 0.065) were observed in immune-challenged pigs. A decrease in muscle cross-sectional area of fibers and a shift from myosin heavy chain (MHC)-II towards MHC-I fibers (p < 0.05) were observed in immune-challenged pigs. These results indicated that ISS reduces PD not only by suppressing the whole-body protein synthesis and degradation rates, but also by decreasing the efficiency of PD in growing pigs. In addition, ISS induces atrophy in skeletal muscles and favors a slow-twitch oxidative fiber type composition.
AB - The effects of immune system stimulation (ISS), induced by repeated injection of Escherichia coli lipopolysaccharide, on the whole-body protein synthesis versus degradation rates, the efficiency of protein deposition (PD), and muscle fiber characteristics in pigs were evaluated. Twelve growing gilts were assigned to two levels of amino acid intake that was predicted based on the potential of each group’s health status for PD and feed intake. Isotope tracer, nitrogen balance, and immunohistochemical staining techniques were used to determine protein turnover, PD, and muscle fiber characteristics, respectively. Protein synthesis, degradation, and PD were lower in immune-challenged pigs than in control pigs (p < 0.05). Strong tendencies for a higher protein synthesis-to-PD ratio (p = 0.055) and a lower protein synthesis-to-degradation ratio (p = 0.065) were observed in immune-challenged pigs. A decrease in muscle cross-sectional area of fibers and a shift from myosin heavy chain (MHC)-II towards MHC-I fibers (p < 0.05) were observed in immune-challenged pigs. These results indicated that ISS reduces PD not only by suppressing the whole-body protein synthesis and degradation rates, but also by decreasing the efficiency of PD in growing pigs. In addition, ISS induces atrophy in skeletal muscles and favors a slow-twitch oxidative fiber type composition.
KW - Immune system stimulation
KW - Muscle fibers
KW - Pigs
KW - Protein turnover
UR - http://www.scopus.com/inward/record.url?scp=85099549722&partnerID=8YFLogxK
U2 - 10.3390/ANI9060323
DO - 10.3390/ANI9060323
M3 - Article
AN - SCOPUS:85099549722
SN - 2076-2615
VL - 9
SP - 1
EP - 16
JO - Animals
JF - Animals
IS - 6
M1 - 323
ER -