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Updated: Jul 18, 2026

Purification of the Sarco-Endoplasmic Reticulum Ca2+-ATPase from Rabbit Muscle
Published on: March 21, 2025
Effect of some antioxidants on sarcoplasmic reticulum Ca2+-ATPase activity from rabbit skeletal muscle
Miriam Strosová1, Janka Karlovská, Pavol Galbavý
1Institute of Experimental Pharmacology, Slovak Academy of Sciences, Bratislava, Slovakia. exfamima@savba.sk
Objectives:
Effects of phenolic antioxidants, synthetized (trolox, pyridoindole stobadine) and plant extracts (EGb 761 and Pycnogenol) were investigated on the activity of Ca(2+)-ATPase from sarcoplasmic reticulum (SR) of rabbit skeletal muscle to examine their potency to modulate the activity of this calcium level regulating enzyme.
Methods:
SR vesicles and pure Ca(2+)-ATPase were isolated by ultracentrifugation. Ca(2+)-ATPase activity was measured spectrophotometrically by enzyme-coupled assay.
Results:
Pycnogenol (Pyc) significantly decreased the activity of Ca(2+)-ATPase incorporated into SR vesicles as well as the activity of purified Ca(2+)-ATPase, the latter with respect to both enzyme substrates, Ca(2+) and ATP. Trolox, stobadine and EGb 761 did not influence significantly the activity SR- vesicle incorporated or pure Ca(2+)-ATPase, the latter with respect to either substrate, in spite of alterations of kinetic parameters in some cases.
Conclusions:
The decrease of SR Ca(2+)-ATPase activity induced by Pyc may be associated with its proapoptotic and anticancerogenic properties.
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