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001-es BibID:BIBFORM068537
Első szerző:Kovács Árpád (kardiológus)
Cím:Myosin heavy chain and cardiac troponin T damage is associated with impaired myofibrillar ATPase activity contributing to sarcomeric dysfunction in Ca2+-paradox rat hearts / Árpád Kovács, Judit Kalász, Enikő T. Pásztor, Attila Tóth, Zoltán Papp, Naranjan S. Dhalla, Judit Barta
Dátum:2017
ISSN:0300-8177
Megjegyzések:This study aimed to explore the potential contribution of myofibrils to contractile dysfunction in Ca2+-paradox hearts. Isolated rat hearts were perfused with Krebs?Henseleit solution (Control), followed by Ca2+-depletion, and then Ca2+-repletion after Ca2+-depletion (Ca2+-paradox) by Langendorff method. During heart perfusion left ventricular developed pressure (LVDP), end-diastolic pressure (LVEDP), rate of pressure development (+?dP/dt), and pressure decay (-dP/dt) were registered. Control LVDP (127.4???6.1 mmHg) was reduced during Ca2+-depletion (9.8???1.3 mmHg) and Ca2+-paradox (12.9???1.3 mmHg) with similar decline in +dP/dt and ?dP/dt. LVEDP was increased in both Ca2+-depletion and Ca2+-paradox. Compared to Control, myofibrillar Ca2+-stimulated ATPase activity was decreased in the Ca2+-depletion group (12.08???0.57 vs. 8.13???0.19 ?mol Pi/mg protein/h), besides unvarying Mg2+ ATPase activity, while upon Ca2+-paradox myofibrillar Ca2+-stimulated ATPase activity was decreased (12.08???0.57 vs. 8.40???0.22 ?mol Pi/mg protein/h), but Mg2+ ATPase activity was increased (3.20???0.25 vs. 7.21???0.36 ?mol Pi/mg protein/h). In force measurements of isolated cardiomyocytes at saturating [Ca2+], Ca2+-depleted cells had lower rate constant of force redevelopment (ktr,max, 3.85???0.21) and unchanged active tension, while those in Ca2+-paradox produced lower active tension (12.12???3.19 kN/m2) and ktr,max (3.21???23) than cells of Control group (25.07???3.51 and 4.61???22 kN/m2, respectively). In biochemical assays, ?-myosin heavy chain and cardiac troponin T presented progressive degradation during Ca2+-depletion and Ca2+-paradox. Our results suggest that contractile impairment in Ca2+-paradox partially resides in deranged sarcomeric function and compromised myofibrillar ATPase activity as a result of myofilament protein degradation, such as ?-myosin heavy chain and cardiac troponin T. Impaired relaxation seen in Ca2+-paradoxical hearts is apparently not related to titin, rather explained by the altered myofibrillar ATPase activity.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Calcium paradox
Myofibrillar ATPase activity
Isolated cardiomyocytes
Myofilament protein degradation
Megjelenés:Molecular and Cellular Biochemistry 403 : 1-2 (2017), p. 57-68. -
További szerzők:Kalász Judit (1986-) (molekuláris biológus) Pásztorné Tóth Enikő (1966-) (laboratóriumi analitikus) Tóth Attila (1971-) (biológus) Papp Zoltán (1965-) (kardiológus, élettanász) Dhalla, Naranjan S. Barta Judit (1975-) (kardiológus)
Pályázati támogatás:GINOP-2.3.2-15-2016-00043
GINOP
K116940
OTKA
K109083
OTKA
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