Activation of Ca2+ release from sarcoplasmic reticulum vesicles by 4-alkylphenols

Arch Biochem Biophys. 1993 Mar;301(2):216-20. doi: 10.1006/abbi.1993.1136.


4-Alkylphenols induce Ca2+ release from junctional (terminal cisternae) sarcoplasmic reticulum vesicles, but not from nonjunctional sarcoplasmic reticulum vesicles. The 4-alkylphenol concentration required to induce Ca2+ release decreases about threefold for every methylene carbon increase in the alkyl chain length, indicating that the Ca(2+)-releasing potency of 4-alkylphenols is related to their ability to partition into the membrane. The rate and amount of Ca2+ release induced by relatively low 4-octylphenol concentrations (25 nmol/mg protein) are altered by the sarcoplasmic reticulum Ca2+ channel activators, Ca2+ and ATP, and the Ca2+ channel inhibitors, Mg2+ and ruthenium red. Ca2+ release induced by 250 nmol 4-octylphenol/mg protein is much less influenced by Ca2+ channel activators and inhibitors; however, even at this high 4-octylphenol concentration, Ca2+ release is not induced from nonjunctional sarcoplasmic reticulum vesicles. The data indicate that 4-alkylphenols induce Ca2+ release by activating the sarcoplasmic reticulum Ca2+ channel.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Calcium Channels / drug effects
  • Calcium Channels / metabolism*
  • Calcium-Transporting ATPases / metabolism
  • Dose-Response Relationship, Drug
  • Drug Contamination
  • Neuromuscular Junction / metabolism*
  • Phenols / pharmacology*
  • Rats
  • Sarcoplasmic Reticulum / drug effects
  • Sarcoplasmic Reticulum / enzymology
  • Sarcoplasmic Reticulum / metabolism*


  • Calcium Channels
  • Phenols
  • 4-octylphenol
  • 4-ethylphenol
  • Calcium-Transporting ATPases
  • 4-nonylphenol
  • Calcium