1. mRNA levels of the calpain system in longissimus muscle of young pigs during prolonged feeding of a protein-free diet.
- Author
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van den Hemel-Grooten HN, te Pas MF, van den Bosch TJ, Garssen GJ, Schreurs VV, and Verstegen MW
- Subjects
- Aging physiology, Animals, Base Sequence, Biopsy methods, Biopsy veterinary, Body Weight physiology, Calcium-Binding Proteins analysis, Calcium-Binding Proteins metabolism, Calpain analysis, Calpain metabolism, DNA Primers analysis, DNA Primers chemistry, DNA Primers genetics, DNA Probes analysis, DNA Probes chemistry, DNA Probes genetics, DNA, Complementary chemistry, DNA, Complementary genetics, DNA, Complementary metabolism, Eating physiology, Enzyme-Linked Immunosorbent Assay methods, Enzyme-Linked Immunosorbent Assay veterinary, Male, Muscle, Skeletal metabolism, Muscle, Skeletal pathology, Polymerase Chain Reaction methods, Polymerase Chain Reaction veterinary, RNA, Messenger genetics, RNA, Messenger metabolism, Swine growth & development, Swine physiology, Weight Gain physiology, Aging metabolism, Calcium-Binding Proteins genetics, Calpain genetics, Diet veterinary, Diet, Protein-Restricted standards, Muscle, Skeletal chemistry, RNA, Messenger analysis, Swine metabolism
- Abstract
This experiment was conducted to investigate the effects of feeding a protein-free diet on mRNA levels of the calpain system in skeletal muscle of growing pigs during a 15-d feeding trial. Twenty crossbred barrows were divided into two dietary treatments: control or protein-free diet (mean initial weight for both groups: 38.3 kg). Daily diets were provided at 2.5 times energy for maintenance (twice a day). On d 0, 3, and 14, biopsies were taken from longissimus muscle between the third and fourth ribs (d 0 and 3) and between the fourth and fifth rib (d 14). On d 15, animals were slaughtered and longissimus muscles were dissected and analyzed for calpastatin, and mu- and m-calpain activity. From biopsies, mRNA level of skeletal muscle calpain, mu- and m-calpain, and calpastatin were measured using reversed transcription PCR. Subsequently, PCR products were quantified using ELISA. Feeding the protein-free diet lowered growth rate to almost zero. Only total level of mRNA of mu-calpain on d 14 was influenced by dietary treatments, being lower for the protein-free group than for the control group (P < .05). However, proteolytic activities were not different between treatments. Total RNA concentration in longissimus muscle decreased during the experiment for both treatments, but on d 14 this was more pronounced for the protein-free than for the control group (P < .05). If mRNA levels were corrected for this change, specific mRNA level on d 14 of skeletal muscle calpain and mu-calpain were lower (P < .05) for the protein-free than for the control group. These data suggest that activity of the components of the calpain system are differentially regulated.
- Published
- 1997
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