# EXERCISE-INDUCED GROWTH OF ADULT RAT SKELETAL MUSCLE

> **NIH NIH R01** · UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON · 1987 · $114,225

## Abstract

A long-term aim is to delineate the mechanisms by which chronic
changes in contractile activity alter the phenotypic expression of
skeletal muscle.  In the regrowth of of atrophied skeletal muscle
after ending limb immobilization, all proteins increase in response
to normal muscle usage.  Further increases in all proteins in
normal adult skeletal muscles are only possible if it undergoes
maximal loading exercise, such as weight-lifting.  In contrast,
repetitive, low-intensity exercise like running results in no
enlargement of normal muscle, but causes an preferential
expression of mitochondrial proteins, such as cytochrome c.  A
strategy of the present application is to compare the responses of
mrna levels, protein synthetic machinery and potential molecular
signals controlling the upregulation of specific protein quantities
in different types of exercises known to cause various phenotypic
expressions.

The following methods will be employed in the comparison among
exercises.  In situ hybridization will permit the localization of
transcripts to nuclei by using intron probes, so a determination
can be made as the time when changes in the levels of specific
nuclear transcripts occur after the exercise and for which
transcripts.  The four cytochrome c mRNAs will be isolated from
a cDNA library, cloned, sequenced and translated so as to provide
information on the functional significance of shifts in their
relative profiles which occur during regrowth from atrophy and
during a program of repeated daily bouts of running.  A rat
genomic library will be screened for fragments containing 5'
upstream and coding sequences for somatic cytochrome c, a
skeletal actin, fast myosin-heavy-chain and rRNA for the
purposes of obtaining intron probes for in situ hybridization.  Also,
the 5' stream sequences will be used for a further proposal to
study regulatory sequences for gene expression.  In accordance
with this long-range plan, studies are initiated in the present
application to identify potential candidates for signals which may
interact,directly r indirectly through a cascade, with the 5'
untranscribed regulatory region of the genome.  The potential
roles of the oncogenes, ATP, creatine phosphate, H+, and Ca++as
the linkers from increased muscle usage to differential gene
expression will be considered.

## Key facts

- **NIH application ID:** 3155034
- **Project number:** 2R01AR019393-11
- **Recipient organization:** UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
- **SAM.gov UEI:** ZUFBNVZ587D4
- **Principal Investigator:** FRANK W BOOTH
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $114,225
- **Award type:** 2
- **Project period:** 1979-08-01 → 1991-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3155034

## Citation

> US National Institutes of Health, RePORTER application 3155034, EXERCISE-INDUCED GROWTH OF ADULT RAT SKELETAL MUSCLE (2R01AR019393-11). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3155034. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*