Burn-induced stimulation of lysosomal enzyme synthesis in skeletal muscle

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:7189845

Odessey, R

A localized burn injury to a rat hindlimb results in atrophy of soleus muscle (in the absence of cellular damage) which is attributable to an increase in muscle protein breakdown. Previous work has shown that lysosomal enzyme activities (cathepsins B, H, L, and D) are elevated in muscle from the burned leg by 50% to 100%. There is no change in endogenous neutral protease activity (+/- Ca/sup + +/). The increase in protease activity can not be attributed to changes in endogenous protease inhibitors. The latency ((Triton X100 treated - control)/triton treated) of lysosomal enzymes is approximately 50% and is not altered by burn injury. The rate of sucrose uptake is also not altered by burn. These experiments suggest that the rate of substrate supply to the lysosomal apparatus via endocytosis or autophagocytosis is not altered by burn. When muscles are preincubated with /sup 3/H-phenylalanine or /sup 3/H-mannose burn increased incorporation into protein of the fraction containing lysosomes by 100%. Preincubation in the presence of tunicamycin (an inhibitor of glycoprotein synthesis) inhibited incorporation of both labels into a microsomal fraction of the muscle from the burned leg, but has little effect on incorporation in the control muscle. These findings are consistent with the hypothesis that the burn-induced increase in protein breakdown is caused by an increase in lysosomal protease synthesis.

• Research Organization: Louisiana State Univ. Medical Center, New Orleans
• OSTI ID: 7189845
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
550901 -- Pathology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
AMINO ACIDS
ANIMALS
BODY
BODY AREAS
BURNS
CARBOHYDRATES
CARBOXYLIC ACIDS
CELL CONSTITUENTS
ENZYME ACTIVITY
ENZYME INHIBITORS
ENZYMES
HEXOSES
HYDROLASES
INJURIES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIMBS
LYSOSOMES
MAMMALS
MANNOSE
METABOLISM
MONOSACCHARIDES
MUSCLES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANOIDS
PATHOGENESIS
PEPTIDE HYDROLASES
PHENYLALANINE
PROTEINS
RATS
RODENTS
SACCHARIDES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES