Uncoupling of muscle and blood platelets Ca2+ transport ATPases by heparin. Regulation by K+.

摘要: Heparin (1-10 micrograms/ml) inhibits the Ca2+ transport ATPases found in sarcoplasmic reticulum of skeletal muscle, plasma membrane red cells, and dense tubular system blood platelets, but not (Na+ + K+)-ATPase or mitochondrial F1-ATPase. In reversal pump, heparin uncouples synthesis ATP from efflux phosphorylation Ca(2+)-ATPase by Pi, has no effect ATP. The on muscle is abolished KCl NaCl (100 mM) to a lesser extent LiCl. These monovalent cations are effective as antagonists platelet Ca(2+)-ATPase. effects antagonized polyamines spermine, spermidine, ruthenium red. Unlike KCl, equally counteracting both Ca(2+)-ATPases. addition heparin, Ca(2+)-ATPases platelets also inhibited dextran sulfate fucose-branched chondroitin sulfate. inhibition promoted these glycosaminoglycans same manner heparin. Heparan sulfate, hyaluronic acid have studied.