Work

Evidence that lysosomes are not involved in the degradation of myofibrillar proteins in rat skeletal muscle

Year: 1986

Type: article

Abstract: To examine the role of lysosomes in the degradation of skeletal-muscle myofibrillar proteins, we measured the release of N tau-methylhistidine from perfused muscle of starved and fed rats in the presence or absence of agents that inhibit lysosomal proteinase activity. After 1 day of starvation, the release of N tau-methylhistidine by perfused muscle of 4-, 8- and 24-week-old rats increased by 322, 159 and 134% respectively. On the other hand, total protein breakdown, assessed by tyrosine release, increased by 62, 20 and 20% respectively. Inhibitors of lysosomal proteinases as well as high concentrations of insulin or amino acids failed to diminish the release of N tau-methylhistidine by perfused muscle of starved and fed rats, despite a 25-35% inhibition of total protein breakdown. The data strongly suggest that the complete breakdown of myofibrillar proteins occurs via a non-lysosomal pathway. They also suggest that total proteolysis, which primarily reflects non-myofibrillar protein breakdown, occurs at least in part within lysosomes.

Source: Biochemical Journal

DOI: 10.1042/bj2340237

Authors: B B Lowell, N B Ruderman, M N Goodman

Institution: Boston University

Language: English

Topic: Muscle metabolism and nutrition

Subfield: Nutrition and Dietetics

Field: Nursing

Domain: Health Sciences

Open Access status: bronze

Funders: National Institutes of Health, U.S. Public Health Service

Awards: G2059022924, PROTEIN SPARING IN STARVATION--EFFECT OF AGE &OBESITY, G435405106