caa a22 4500 477119395 CHVBK 20180405111631.0 cr unu---uuuuu 170330e19960301xx s 000 0 eng 10.1007/BF00240048 doi (NATIONALLICENCE)springer-10.1007/BF00240048 Relationship between mechanical dysfunction and depression of sarcolemmal Ca2+-pump activity in hearts perfused with oxygen free radicals [Elektronische Daten] [Taku Matsubara, Naranjan Dhalla] Although in vitro studies have shown that oxygen free radicals depress the sarcolemmal Ca2+-pump activity and thereby may cause the occurrence of intracellular Ca2+ overload for the genesis of contractile failure, the exact relationship between changes in sarcolemmal Ca2+-pump activity and cardiac function due to these radicals is not clear. In this study we examined the effects of oxygen radicals on sarcolemmal Ca2+ uptake and Ca2+-stimulated ATPase activities as well as contractile force development by employing isolated rat heart preparations. When hearts were perfused with medium containing xanthine plus xanthine oxidase, the sarcolemmal Ca2+-stimulated ATPase activity and ATP-dependent Ca2+ accumulation were depressed within 1 min whereas the developed contractile force, rate of contraction and rate of relaxation were increased at 1 min and decreased over 3-20 min of perfusion. The resting tension started increasing at 2 min of perfusion with xanthine plus xanthine oxidase. Catalase showed protective effects against these alterations in heart function and sarcolemmal Ca2+-pump activities upon perfusion with xanthine plus xanthine oxidase whereas superoxide dismutase did not exert such effects. The combination of catalase and superoxide dismutase did not produce greater effects in comparison to catalase alone. These results are consistent with the view that the depression of heart sarcolemmal Ca2+ pump activities may result in myocardial dysfunction due to the formation of hydrogen peroxide and/or hydroxyl radicals upon perfusing the hearts with xanthine plus xanthine oxidase. Kluwer Academic Publishers, 1996 oxygen free radicals nationallicence cardiac contractile failure nationallicence sarcolemmal Ca2+-pump nationallicence activity nationallicence sarcolemmal Ca2+-stimulated ATPase nationallicence rat heart nationallicence Matsubara Taku Division of Cardiovascular Sciences, St. Boniface General Hospital Research Centre and Department of Physiology, Faculty of Medicine, University of Manitoba, R2H 2A6, Winnipeg, Manitoba, Canada aut Dhalla Naranjan Division of Cardiovascular Sciences, St. Boniface General Hospital Research Centre and Department of Physiology, Faculty of Medicine, University of Manitoba, R2H 2A6, Winnipeg, Manitoba, Canada aut Molecular and Cellular Biochemistry Kluwer Academic Publishers; http://www.wkap.nl 160-161/1(1996-03-01), 179-185 0300-8177 160-161:1<179 1996 160-161 11010 https://doi.org/10.1007/BF00240048 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00240048 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Matsubara Taku Division of Cardiovascular Sciences, St. Boniface General Hospital Research Centre and Department of Physiology, Faculty of Medicine, University of Manitoba, R2H 2A6, Winnipeg, Manitoba, Canada aut NATIONALLICENCE 700 1- Dhalla Naranjan Division of Cardiovascular Sciences, St. Boniface General Hospital Research Centre and Department of Physiology, Faculty of Medicine, University of Manitoba, R2H 2A6, Winnipeg, Manitoba, Canada aut NATIONALLICENCE 773 0- Molecular and Cellular Biochemistry Kluwer Academic Publishers; http://www.wkap.nl 160-161/1(1996-03-01), 179-185 0300-8177 160-161:1<179 1996 160-161 11010 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer