# OPTICAL SIGNALS AND CALCIUM RELEASE IN MUSCLE

> **NIH NIH R01** · UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN · 1989 · $76,776

## Abstract

The amount of force produced by a muscle cell is a function of the
intracellular calcium ion concentration.  An intracellular organelle called
the sarcoplasmic reticulum sequesters calcium from the cytoplasm to cause
muscle relaxation and releases it to initiate contraction.  Although it is
known that a change in the electrical voltage across the cell surface
membrane can stimulate calcium release from the SR, the cellular mechanisms
that control and regulate the release process are poorly understood.  This
project is designed to gain a greater understanding of these mechanisms by
studying the way in which a variety of drugs and ions modulate calcium
release from the sarcoplasmic reticulum.  Single amphibian muscle cells
will be used.  The surface membranes of these cells are removed by
microdissection so that the conditions surrounding the SR can be rigorously
controlled.  This technique causes only minor disruption of normal cellular
structure.  A quantitative measure of the rate of calcium release from the
sarcoplasmic reticulum in these isolated cells will be obtained using an
optical technique employing the calcium sensitive dye Arsenazo III.  In
other experiments the permeability of the SR membrane to potassium ion will
be monitored using radioactive tracer techniques.  Specific experiments are
designed to determine the mechanism of action of calcium channel blocking
agents in decoupling the spread of activation from the transverse tubular
membranes to the sarcoplasmic reticulum.  In addition, the importance of
counterion movement in modulating the magnitude of calcium efflux will be
investigated by using potassium channel blocking agents.  The results of
these experiments will add to our knowledge of the cellular processes
involved in the activation of contraction in skeletal muscle.  A better
understanding of the mechanisms underlying this process in healthy cells
will improve our understanding of the changes which occur in the activation
of cells under a variety of pathological states.

## Key facts

- **NIH application ID:** 3156172
- **Project number:** 5R01AR032062-10
- **Recipient organization:** UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
- **SAM.gov UEI:** Y8CWNJRCNN91
- **Principal Investigator:** PHILIP M BEST
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1989
- **Award amount:** $76,776
- **Award type:** 5
- **Project period:** 1979-12-01 → 1990-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3156172

## Citation

> US National Institutes of Health, RePORTER application 3156172, OPTICAL SIGNALS AND CALCIUM RELEASE IN MUSCLE (5R01AR032062-10). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3156172. Licensed CC0.

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