Detection of calcium sparks in intact and permeabilized skeletal muscle fibers

Methods Mol Biol. 2012:798:395-410. doi: 10.1007/978-1-61779-343-1_23.

Abstract

Ca(2+) sparks are the elementary units of Ca(2+) signaling in striated muscle fibers that appear as highly localized Ca(2+) release events through ryanodine receptor (RyR) Ca(2+) release channels in the sarcoplasmic reticulum (SR). While these events are commonly observed in resting cardiac myocytes, they are rarely seen in resting skeletal muscle fibers. Since Ca(2+) spark analysis can provide extensive data on the Ca(2+) handling characteritsics of normal and diseased striated muscle, there has been interest in developing methods for observing Ca(2+) sparks in skeletal muscle. Previously, we discovered that stress generated by osmotic pressure changes induces a robust Ca(2+) spark response confined in close spatial proximity to the sarcolemmal membrane in wild-type intact mammalian muscles. Our studies showed these peripheral Ca(2+) sparks (PCS) were altered in dystrophic or aged skeletal muscles. Other methods to induce Ca(2+) sparks include permeabilization of the sarcolemmal membrane with detergents, such as saponin. In this chapter, we will discuss the methods for isolation of muscle fibers, the techniques for inducing Ca(2+) sparks in these isolated fibers, and provide guidance on the analysis of data from these experiments.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / analysis*
  • Calcium / metabolism*
  • Calcium Signaling* / drug effects
  • Cell Separation / methods
  • Mice
  • Muscle Fibers, Skeletal / cytology
  • Muscle Fibers, Skeletal / drug effects*
  • Muscle Fibers, Skeletal / metabolism*
  • Osmotic Pressure / drug effects
  • Rats
  • Rats, Sprague-Dawley
  • Saponins / pharmacology

Substances

  • Saponins
  • Calcium