# EXCITATION-CONTRACTION COUPLING IN SKELETAL MUSCLE

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA LOS ANGELES · 1990 · $145,277

## Abstract

The possibility that a chemical transmission mechanism, involving
inositol (1,4,5) trisphosphate (InsP3) as a second messenger, is
responsible for excitation-contraction coupling in skeletal muscle
will be studied in physiological/biochemical experiments.  The
release of phosphoinositide-derived inositol phosphates induced by
the electrical activation of skeletal muscle will be studied by
the biochemical analysis of metabolic constituents obtained from
rapidly frozen muscles.  The ability of InsP3 and other inositol
phosphates (cyclic InsP3) to rapidly induce release from the
sarcoplasmic reticulum (SR) will be assessed using optical
techniques in skinned skeletal muscle fibers.  The modulation of
this ability by several agents will also be investigated.  Novel
techniques to produce rapid release of Ca2+ and inositol phosphates
(using photoreleasable derivatives) will be developed in order to
investigate the kinetic response of the SR to putative agonists.
These studies will give important kinetic information on the
chemical modulation of the physiological process of Ca2+ release
and they will complement our new findings about the nature of the
transmission delay in E-C coupling.  The role of Na and K
conductances in the T-tubule depolarization and in possible ion
depletion/accumulation phenomena will be studied with the aid of
potentiometric dyes.  The possibility that voltage dependent
phospholipase C activity is endogenously present in the T tubule
membranes will be directly tested in vitro.  Studies in barnacle
muscle fibers will allow us to evaluate the role of inositol
phosphates on the E-C coupling of invertebrate muscle and will
provide insights into the role of extracellular Ca in the
regulation of this process.

## Key facts

- **NIH application ID:** 3155284
- **Project number:** 5R01AR025201-11
- **Recipient organization:** UNIVERSITY OF CALIFORNIA LOS ANGELES
- **SAM.gov UEI:** RN64EPNH8JC6
- **Principal Investigator:** Julio L Vergara
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1990
- **Award amount:** $145,277
- **Award type:** 5
- **Project period:** 1978-12-01 → 1992-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3155284

## Citation

> US National Institutes of Health, RePORTER application 3155284, EXCITATION-CONTRACTION COUPLING IN SKELETAL MUSCLE (5R01AR025201-11). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3155284. Licensed CC0.

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