REGULATION OF SKELETAL MUSCLE METABOLISM

Project: Research project

Description

The overall objectives of this project are to identify and examine the
regulatory steps involved in the control of protein turnover and amino acid
metabolism in skeletal muscle with respect to: a) the effects of hormone
deprivation and replacement in vivo; b) the modulation by insulin,
glucocorticoids, growth hormone, thyroxine, and certain other hormonal
interactions in vitro; and c) the influence of diet, substrate availability, and
contractile activity. We are also attempting to determine the influence of
these factors on the turnover of ribosomal RNA, investigate the mechanisms of
intracellular protein degradation, and further characterize the reactions
involved in peptide initiation.
The studies employ the perfused rat hemicorpus as the principal experimental
model. This preparation consists predominantly of skeletal muscle and remains
in excellent physiological condition during perfusion. The preparation is used
to localize the effects of hormones, substrates, and other factors to specific
steps in the pathway of protein synthesis, i.e. amino acid transport, amino acid
activation, peptide initiation, and peptide elongation. Effects of the various
conditions on rates of protein degradation are determined in the perfused
hemicorpus and related to the activities of various lysosomal and non-lysosomal
proteases in skeletal muscle. The perfused hemicorpus also permits studies of
the biochemical mechanisms underlying alanine and glutamine production and
branched-chain amino acid oxidation in skeletal muscle.
StatusFinished
Effective start/end date9/1/778/31/87

Funding

  • National Institutes of Health

Fingerprint

Skeletal Muscle
Peptides
Proteolysis
Amino Acids
Ribosomal RNA
Glutamine
Thyroxine
Alanine
Glucocorticoids
Growth Hormone
Proteins
Perfusion
Hormones
Insulin
Diet