Journal article
The effects of ryanodine on passive calcium fluxes across sarcoplasmic reticulum membranes
The Journal of biological chemistry, Vol.262(6), pp.2711-2718
1987
DOI: 10.1016/S0021-9258(18)61565-0
PMID: 2434490
Abstract
Ryanodine at concentrations of 0.01-10 microM increased, while greater concentrations of 10-300 microM decreased the calcium permeability of both rabbit fast twitch skeletal muscle junctional and canine cardiac sarcoplasmic reticulum membranes. Ryanodine did not alter calcium binding by either sarcoplasmic reticulum membranes or the calcium binding protein, calsequestrin. Therefore, the effects by this agent appear to involve only changes in membrane permeability, and the characteristics of the calcium permeability pathway affected by ryanodine were those of the calcium release channel. Consistent with this, the actions by ryanodine were localized to junctional sarcoplasmic reticulum membranes and were not observed with either longitudinal sarcoplasmic reticulum or transverse tubular membranes. In addition, passage of the junctional sarcoplasmic reticulum membranes through a French press did not diminish the effects of ryanodine indicating that intact triads were not required. Under the conditions used for the permeability studies, the binding of [3H]ryanodine to skeletal junctional sarcoplasmic reticulum membranes was specific and saturable, and Scatchard analyses indicated the presence of a single binding site with a Kd of 150-200 nM and a maximum capacity of 10.1-18.9 pmol/mg protein. [3H]ryanodine binding to this site and the increase in membrane calcium permeability caused by low concentrations of ryanodine had similar characteristics suggesting that actions at this site produce this effect. Depending on the assay conditions used, ryanodine (100-300 microM) could either increase or decrease ATP-dependent calcium accumulation by skeletal muscle junctional sarcoplasmic reticulum membranes indicating that the alterations of sarcoplasmic reticulum membrane calcium permeability caused by this agent can be determined in part by the experimental environment.
Details
- Title: Subtitle
- The effects of ryanodine on passive calcium fluxes across sarcoplasmic reticulum membranes
- Creators
- Frank A Lattanzio Jr - Univ. Texas health sci. cent., dep. physiology, Dallas TX 75235, United StatesRobert G Schlatterer - Univ. Texas health sci. cent., dep. physiology, Dallas TX 75235, United StatesMichael Nicar - Univ. Texas health sci. cent., dep. physiology, Dallas TX 75235, United StatesKevin P Campbell - Univ. Texas health sci. cent., dep. physiology, Dallas TX 75235, United StatesJohn L Sutko - Univ. Texas health sci. cent., dep. physiology, Dallas TX 75235, United States
- Resource Type
- Journal article
- Publication Details
- The Journal of biological chemistry, Vol.262(6), pp.2711-2718
- DOI
- 10.1016/S0021-9258(18)61565-0
- PMID
- 2434490
- NLM abbreviation
- J Biol Chem
- ISSN
- 0021-9258
- eISSN
- 1083-351X
- Publisher
- American Society for Biochemistry and Molecular Biology; Bethesda, MD
- Language
- English
- Date published
- 1987
- Academic Unit
- Neurology; Molecular Physiology and Biophysics; Iowa Neuroscience Institute
- Record Identifier
- 9984068366802771
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