Modulation by fatty acids of Ca2+ fluxes in sarcoplasmic-reticulum vesicles

Abstract

The fatty acids palmitic (C(16:0)), stearic (C(18:0)), arachidic (C(20:0)) and arachidonic (C(20:4)) acids inhibit Ca2+ uptake and enhance Ca2+ efflux measured in vesicles derived from the sarcoplasmic reticulum of skeletal muscle. These effects of the fatty acids are impaired by the Ca2+-ATPase ligands Mg2+, Ca2+ and K+, and by drugs that block the leakage of Ca2+ through the Ca2+-ATPase such as Ruthenium Red, spermine and thapsigargin.