# SKELETAL MUSCLE EXCITATION-CONTRACTION COUPLING

> **NIH NIH R01** · UNIVERSITY OF MINNESOTA · 1993 · $181,198

## Abstract

Skeletal muscle contracts as result of Ca2+ released internally in response
to an electrical signal from the surface membrane, but the exact steps of
excitation-contraction (EC) coupling are not known.  This project is
designed to evaluate the adequacy of a single skinned (plasma membrane
peeled off) fiber preparation for the study of physiological EC coupling
mechanisms, or in other words, skinned fiber Ca2+ release stimulated by via
plasma membrane depolarization.  The hypotheses to be tested are:  1) Ca2+
release can be elicited by a mechanism inhibited by cardiac-glycosides (CG)
and 2) the CG-sensitive component of Ca2+ release is governed by
depolarization of plasma membranes (transverse tubules) within the skinned
fibers.  Rabbit fast and slow twitch fibers and frog fast twitch skeletal
muscle fibers will be studied as to their skinned fiber Ca2+ release
properties.  Ca2+ release will be assayed as isometric tension transients
and net 45 Ca2+ release.  Stimuli for release are abrupt changes in ionic
constituents of the bathing solution thought to bring about depolarization
of any sealed-off internal membranes and caffeine.  Specific experiments
will test whether or not the CG-sensitive component of Ca2+ release is a
consequence of depolarization of sealed-off TT's in the skinned fibers and
determine the characteristics of CG-sensitive component of Ca2+ release.

## Key facts

- **NIH application ID:** 3157047
- **Project number:** 5R01AR035132-08
- **Recipient organization:** UNIVERSITY OF MINNESOTA
- **SAM.gov UEI:** KABJZBBJ4B54
- **Principal Investigator:** Sue Karen Donaldson
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $181,198
- **Award type:** 5
- **Project period:** 1990-06-01 → 1994-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3157047

## Citation

> US National Institutes of Health, RePORTER application 3157047, SKELETAL MUSCLE EXCITATION-CONTRACTION COUPLING (5R01AR035132-08). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3157047. Licensed CC0.

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