# CA CHANNELS IN SKELETAL MUSCLE FIBERS

> **NIH NIH R01** · BAYLOR COLLEGE OF MEDICINE · 1991 · $150,717

## Abstract

The long term objective of the proposed research project is to
define the functional role of voltage gated Ca++ entry in skeletal
muscle.  Voltage and current clamp experiments will be carried
out in isolated skeletal muscle from the frog with the cut fiber
preparation in the vaseline gap technique.  Myoplasmic Ca++
transients will be optically measured with Antipyrylazo III.  Ionic
currents, charge movement and changes in intracellular Ca++
concentration will be studied simultaneously.  The slow Ca++
channel is located in the tubular system and it is too slow to be
activated during a single action potential, however this is not the
case for the recently described fast Ca++ channel.  In initial
experiments the effect of reducing external Ca++ on the Ca++
transient associated with the action potential will be investigated.
In order to distinguish the activation of these channel in relation
to charge movement and Ca++ transients, the pharmacology and
modulation of fast and slow Ca++ channels will be studied in
detail.  In addition the recent described fast Ca++ channel will be
further characterize in term of its localization, pharmacology and
kinetic.  These studies will be performed in a comparative way in
preparations with variations of Ca++ channel currents such as the
denervated muscle fiber, the end-plate region and the tail muscle
from tadpoles.  Ca++ channels were recently described in skeletal
tonic fibers, where Ca++ entry may play a role in contraction.
This point will be clarified by simultaneously measuring Ca++
currents, Ca++ transient and charge movement.  An insight on the
role of Ca++ channel activation will be obtained also from
developmental studies, with measurements of Ca++ macroscopic
and single currents that will be performed in primary cultures of
skeletal muscle of new born rats.  To define the physiological role
of voltage gated Ca++ entry in skeletal muscle is a relevant
problem in the medical sciences, since, Ca++ channel alterations
have been recently described in muscle diseases such as muscular
dysgenesis and muscle dystrophia.

## Key facts

- **NIH application ID:** 3159013
- **Project number:** 5R01AR038970-05
- **Recipient organization:** BAYLOR COLLEGE OF MEDICINE
- **SAM.gov UEI:** FXKMA43NTV21
- **Principal Investigator:** ENRICO STEFANI
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1991
- **Award amount:** $150,717
- **Award type:** 5
- **Project period:** 1987-09-01 → 1994-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3159013

## Citation

> US National Institutes of Health, RePORTER application 3159013, CA CHANNELS IN SKELETAL MUSCLE FIBERS (5R01AR038970-05). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3159013. Licensed CC0.

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