1. Regulation of muscle cathepsin B proteolytic activity in protein-depleted patients with chronic diseases
- Author
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Alessandra Bosutti, Beniamino Ciocchi, Gabriele Guarnieri, Gabriele Toigo, Gianni Biolo, Roberta Situlin, Bosutti, Alessandra, Toigo, Gabriele, Ciocchi, Beniamino, Situlin, Roberta, Guarnieri, Gabriele, and Biolo, Gianni
- Subjects
Male ,proteolysis ,medicine.medical_specialty ,Vastus lateralis muscle ,Phenylalanine ,RT-PCR ,Skeletal muscle ,Muscle Proteins ,proteolysi ,Microarray ,Critical Care and Intensive Care Medicine ,Polymerase Chain Reaction ,Protein-Energy Malnutrition ,Cathepsin B ,Internal medicine ,Dietary energy ,medicine ,Humans ,RNA, Messenger ,Muscle, Skeletal ,Cathepsin ,Pig ,Dietary energy, Gene transcription, Microarray, Pig, Skeletal muscle ,Analysis of Variance ,Nutrition and Dietetics ,Nutritional Support ,business.industry ,Biopsy, Needle ,Middle Aged ,Acute Disease ,chronic disease ,Pathophysiology ,medicine.anatomical_structure ,Endocrinology ,Real-time polymerase chain reaction ,Gene transcription ,Chronic Disease ,Regression Analysis ,Female ,Myofibril ,business - Abstract
Background & aims: The lysosomal cathepsin system contributes to degrading cellular skeletal muscle proteins in many catabolic diseases. We have assessed the relationships between cathepsin B mRNA levels and the enzyme activity for this protease in the skeletal muscle of acutely ill patients with severe trauma (n=7) and in patients with a variety of chronic disease states (hemodialysis, n=3; nervous anorexia, n=1; type 2 diabetes, n=2; prolonged immobilization, n=1). Methods: Muscle biopsies were taken from the vastus lateralis muscle in patients and controls to assess tissue levels of cathepsin B mRNA by competitive–quantitative polymerase chain reaction, cathepsin B proteolytic activity and myofibrillar protein content as alkali-soluble protein to DNA ratio (ASP/DNA). In the trauma patients, muscle protein loss was assessed by the arteriovenous balance technique as rate of phenylalanine release from leg muscle. Results: The acute trauma patients exhibited a significant net phenylalanine release from leg muscle (33±4 nmol phenylalanine/min/100 ml leg volume) despite a continuous nutritional support. The muscle ASP/DNA ratio was lower (P
- Published
- 2002
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