# ANALYSIS OF CELLULAR CALCIUM COMPARTMENTS IN MUSCLE

> **NIH NIH R01** · UNIVERSITY OF PITTSBURGH AT PITTSBURGH · 1988 · $74,078

## Abstract

The contractile mechanism of vertebrate striated muscle is activated by the
binding of calcium to troponin.  Studies relating force to free calcium
concentration show that the calcium activating mechanism has the properties of a
cooperative system.  One aspect of this cooperativity is that calcium-receptor
interactions can be modulated by cross-bridge attachments formed between myosin
and actin filaments.  The aim of this study will be to analyze and interpret the
calcium-troponin interaction as a dynamic property of the working myofilament
system.
A double isotope technique and EGTA buffers will be used to make simultaneous
measurements of bound Ca 2 ion, force development, and ATPase activity in rabbit
psoas muscle fibers extracted with detergent and glycerol.  Questions to be
answered are:  1) what is the quantitative relationship between receptor
occupancy, ATPase activity, and the mechanical output?, 2) how do mechanical
parameters such as force and length alter calcium receptor properties?, and 3)
in the intact myofilament system what is the influence on calcium binding of
variations in chemical environment which are known to alter mechanical activity?
 These studies should enhance our understanding of how calcium mobilization and
binding are controlled by the mechanical and chemical conditions which prevail
during the contraction cycle of living muscle.

## Key facts

- **NIH application ID:** 3154713
- **Project number:** 5R01AR010551-23
- **Recipient organization:** UNIVERSITY OF PITTSBURGH AT PITTSBURGH
- **SAM.gov UEI:** MKAGLD59JRL1
- **Principal Investigator:** FRANKLIN FUCHS
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $74,078
- **Award type:** 5
- **Project period:** 1978-05-01 → 1990-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3154713

## Citation

> US National Institutes of Health, RePORTER application 3154713, ANALYSIS OF CELLULAR CALCIUM COMPARTMENTS IN MUSCLE (5R01AR010551-23). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3154713. Licensed CC0.

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